stunthanger.com
General control line discussion => Open Forum => Topic started by: Tim Wescott on January 28, 2015, 10:30:29 PM
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Well, it's January of 2015, and I'm finally starting work on my new stunter for 2014. After much backing and forthing (I owe Bob Hunt at least one totally trouble free purchase of a set of wing cores), and a long hiatus first to build some equipment for Howard Rush's trip to the Worlds, and then to catch up on my work, I'm building a Legacy from a Brodak kit.
The kit came to me from Don Curry, then president of the NW Fireballs. He had been given the kit by someone who got it from who knows where, and he gave it to me because he had no use for it. Somewhere along the line someone got the wing halves built and bollixed it up so badly that it needs a new wing. The thing's a horror. My flying buddy suggested that I string it up on a jig and sheet it, but the spar and leading edge aren't even fully seated in the notches everywhere -- there are spots where there's 3/32" of air between the notch bottom and the spar. So that wing is going onto the campfire at the flying field sometime soon.
I sorta semi remembered that Brodak sold wing kits, so I emailed them and asked. It turns out that while they don't catalog wing kits, if you ask nicely they'll make one for you. It also turns out that you need to be careful what you ask for -- had I asked for a Vector-not-40 wing kit, I would have gotten the right thing the first time. Imagine my disappointment when I finally got my bench cleaned off, a new building board (2' x 8' x 3/4" melamine) laid down, and started building only to find that I had the wrong kit.
Brodak is full of extremely nice, helpful folks who will fix their errors, even if you just want to keep what they shipped you by mistake and buy a rib kit for the right wing. They'll be getting more of my business, for sure.
I bought a set of 60" x 8mm carbon fiber rods from a kite shop to use for my wing jig. This will allow me to build the wing all in one piece if I want. I also got some shorter rods so I can build two halves. This wing is going to be jig built, and it's going to be as straight as I can make it.
While I'm waiting for the correct box of goodies to arrive from Brodak, I decided that I'm going to make this kit with a molded leading edge, and that I'm going to make the buck for it. This should be an adventure, because I've never cut foam for real. Hopefully I won't waste much time on this -- if I do, I may back out of the molded LE decision and just make it the old fashioned way.
Since I'm doing the cutting in an off-the-cuff what-the-heck sort of way, I just bought a chunk of foam from Home Depot. Unfortunately, Home Depot (at least around here) doesn't sell foam thicker than 2". So tonight's work was to make a 4" thick blank using two layers of 2" thick foam.
I'm starting from near-scratch here. I made a bow from a 5/8" dowel, some 1x2, finish nails, and some used .015" flying lines. What you see in the picture has about 29" between the bow arms, which is just about exactly what I need to do the job.
I'm using a 12V power supply that I use for charging batteries. It seems to hold the wire at a decent temperature -- at least, it's not getting hugely hot, and it does cut the foam nicely if I'm patient. My 30 inches of wire pulls about one amp from the supply. I have no clue if it's too hot, too cold or just right -- but I'm confident that with care I can cut a buck that'll be good enough to mold leading edges on.
I made a test cut, freehand with the bow and some scrap foam -- it seemed to come out OK.
My flying buddy had, until today, infinitely more experience cutting foam than me -- he has a friend who cuts foam and chats. I knew from Tom that you want to make tick marks on your cut, and count them out as they go by. After one cut that happened too fast, my assistant suggested that I make the tick marks spaced closer together, and please count them out as eight notes, in 4/4 time (he's a musician. that makes perfect sense if you're a musician).
The final picture is my blanks glued together into one master blank. I'm gluing with epoxy (I don't know what else will cure nicely inside of foam), being careful not to leave any epoxy anywhere that I'll want to cut later. I'm using my favorite relativistic clamping system, that uses the very curvature of space-time itself to induce force on the items being clamped.
Tomorrow I'll cut the buck and either joyously start molding leading edges, or cursing myself for screwing things up somehow.
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On your power supply, does it have any means of controlling the current, or is it just a function of your hot wire's resistance ?
I'm liking that relativistic clamp, so as I can figer out what it is.
Molded LE is the way to go. If your not completely happy with own results let Hunt make a set of bucks for you.
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On your power supply, does it have any means of controlling the current, or is it just a function of your hot wire's resistance ?
It's just constant voltage, that happens to be good enough. I'm sure that if I got more serious I'd want a controllable supply.
I'm liking that relativistic clamp, so as I can figer out what it is.
It's just gravity and weights. Don't tell anyone.
Molded LE is the way to go. If your not completely happy with own results let Hunt make a set of bucks for you.
I'm on a schedule for this one, so if I mess up these bucks I'll build it the old way, and do the next one right.
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I like your spirit and attitude Tim, I bet everything is going to come out great on this. I still sheet those leading edges the old fashioned way so I am anxious to see how this goes.
Mike
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If you were local you could borrow the bucks we got with the Legacy lost foam jig. Actually most modern wings are close enough you could probably use the bucks from just about any lost foam jig.
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If you were local you could borrow the bucks we got with the Legacy lost foam jig. Actually most modern wings are close enough you could probably use the bucks from just about any lost foam jig.
If only. There's probably bucks somewhere in Portland that I could borrow if only I knew who to ask.
If you know me, you know that I can spend a lot of time grinding through all the possibilities before I start a project. But there comes a time where, if you want to make progress, you just have to move forward no matter what -- that's where I am now, and if I'm a bit inefficient because of it, at least I'm moving forward.
Besides, I want to do at least a bit of foam cutting, just to see what all the fuss is about.
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If you go to the building and finishing section at the top of the building part is a thread on how Bobby Hunt does the molding of leading edges. It is great you are trying this as I still have my foam cutting set up from years ago. I had to go with the Home Depot foam to make my wings and such. Yes I did mess up a few pieces of foam learning. Probably would have saved time and money if I had just let Bobby do it for me. But, it was fun.
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Buck back bonded. Life is more fun when you use scrap lumber. The template ends were copied from existing ribs carefully separated from the existing wing. Not readily apparent is the fact that there are 42 tick marks on each template, so that we can count out the cutting process as we go around the core. This was done in my lunch hour, with 5-minute epoxy, so by the time help arrives it should be ready to cut.
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On a buck for stunt wing I think it's best to leave about an inch of foam in front of the templates and cut all the way around the templates. One of the most difficult parts of cutting, especially without a temperature controlled wire is dishing the front of the leading edge. I would guess it will take you many tries to get it right...of course you might be luckier than me. It took me about 10 pieces of foam before I got the hang of it and even then it occassionally goes awray...Just stick with it. Foam is cheap.
The main reason for leaving more foam around the front is that the area (foam area) gets hotter and the cut must go a little faster when there is less of it!
I spent a lot of time in the past cutting combat wings...a little less critical but I'm a bit of a perfectionist when producing something!
I leave the stunt wing cutting to Bob Hunt now because He does such a fantastic job of it. Talk about perfectionists!
Randy Cuberly
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There was foam all the way around the templates, but it did end up dished in the leading edge -- you can see in the picture that we were going much too fast at the end as we went off the edge there. So next time we'll have to go slower (or get a different power supply for the foam cutter).
I just corrected the dishing with a sanding board, making sure that I'm maintaining the right rib contour. I had to take about 1/16" of length off of each end. It's probably not right, but I suspect it's still better than I could do without the molded leading edge.
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I'm totally flying blind here, so much of what I'm doing is b'guess and b'gosh. It all makes sense to me though. Don't go copying this method until you see that I've finished things and gotten good results!
I couldn't see trying to join the leading edge sheet after I formed it, so I made a wide sheet from two pieces. I was also concerned about putting the join between two sheets right at the LE -- so I didn't. The picture shows a central sheet, with the other sheet split in half and glued on to the outside. Everything is tapered to match the taper on the actual LE sheet, except that I took half an inch off of each side of the wide sheet, then half an inch off of each of the split-off pieces. The tapered pieces are glued together, so that the grain will run parallel to the spar and the leading edge, with grain running toward the splices from all sides.
I sorted out the sheets available in the kit -- the two that look most like A grain are my 'middle' sheet, while the ones that look like 'C' grain (actually, they look a bit mixed) are going on the outside.
Glue is Ambroid, mixed 50-50 with acetone (I hang out with an indoor free flight guy, who has poisoned my brain). This allows me to make a nice joint with minimal actual glue left after all the solvent evaporates. Ambroid was chosen because it's light, plenty strong gluing balsa to balsa, it gives me some working time, and it's not soluble in water.
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There was foam all the way around the templates, but it did end up dished in the leading edge -- you can see in the picture that we were going much too fast at the end as we went off the edge there. So next time we'll have to go slower (or get a different power supply for the foam cutter).
I just corrected the dishing with a sanding board, making sure that I'm maintaining the right rib contour. I had to take about 1/16" of length off of each end. It's probably not right, but I suspect it's still better than I could do without the molded leading edge.
Tim,
The reason for increasing the foam around the front is to keep the mass of foam there about the same as on the sides of the template so the wire and foam temperature remains about the same throughout the cut. As the foam gets thinner (less mass) around the front the wire getts hotter and the foam cuts differently. The wire cuts a broader swath which is often the cause of the dishing. Try to keep the foam mass about the same throughout the cut because trying to vary the speed of the cut never works very well.
You also need to maintain a lot of spring tension on the wire as it stretches as it heats (I know you know that as an engineer) but it often has more effect than one thinks on the wire tension...very tight wire means cleaner cut!
Randy Cuberly
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I'm totally flying blind here, so much of what I'm doing is b'guess and b'gosh. It all makes sense to me though. Don't go copying this method until you see that I've finished things and gotten good results!
I couldn't see trying to join the leading edge sheet after I formed it, so I made a wide sheet from two pieces. I was also concerned about putting the join between two sheets right at the LE -- so I didn't. The picture shows a central sheet, with the other sheet split in half and glued on to the outside. Everything is tapered to match the taper on the actual LE sheet, except that I took half an inch off of each side of the wide sheet, then half an inch off of each of the split-off pieces. The tapered pieces are glued together, so that the grain will run parallel to the spar and the leading edge, with grain running toward the splices from all sides.
I sorted out the sheets available in the kit -- the two that look most like A grain are my 'middle' sheet, while the ones that look like 'C' grain (actually, they look a bit mixed) are going on the outside.
Glue is Ambroid, mixed 50-50 with acetone (I hang out with an indoor free flight guy, who has poisoned my brain). This allows me to make a nice joint with minimal actual glue left after all the solvent evaporates. Ambroid was chosen because it's light, plenty strong gluing balsa to balsa, it gives me some working time, and it's not soluble in water.
You're absolutely correct in joining the three parts of the LE sheet before forming it. The center sheet is the one obviously that wraps around the front of the LE so there' not undue stress on the glue joint.
I can't tell from the picture how you are forming it but the idea is to make the form significantly wider (front to back) than the sheet (at least about a quarter inch)...and the width of the formed sheet should be a little wider than what you want for the
actual leading edge sheeting and then trimmed nice and straight after forming. Mark the dimensions you want on the edge of the sheet after forming and while still around the form.
Of course you know to soak the balsa in warm water for about 5 minutes then wipe it dry and carefully wrap it around the form then wrap it fairly tightly with and ACE bandage being very careful to keep the whole thing in place and STRAIGHT...Did I mention be careful and keep it STRAIGHT!!!
I apologize if I'm being too elementary here and you already know all this "crap", but it's very important that you do it this way if you want it to work and not twist your wing when you install it.
I assume you know how to install it and glue it with a long nozzle and CA while the whole thing is stable.
Randy Cuberly
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You're absolutely correct in joining the three parts of the LE sheet before forming it. The center sheet is the one obviously that wraps around the front of the LE so there' not undue stress on the glue joint.
Good, I guessed right then!
I can't tell from the picture how you are forming it but the idea is to make the form significantly wider (front to back) than the sheet (at least about a quarter inch)...and the width of the formed sheet should be a little wider than what you want for the
actual leading edge sheeting and then trimmed nice and straight after forming. Mark the dimensions you want on the edge of the sheet after forming and while still around the form.
Of course you know to soak the balsa in warm water for about 5 minutes then wipe it dry and carefully wrap it around the form then wrap it fairly tightly with and ACE bandage being very careful to keep the whole thing in place and STRAIGHT...Did I mention be careful and keep it STRAIGHT!!!
That pretty much sums up what I'm doing, although without your warning I may have had more errors in the "keeping it straight" department.
I apologize if I'm being too elementary here and you already know all this "crap", but it's very important that you do it this way if you want it to work and not twist your wing when you install it.
I assume you know how to install it and glue it with a long nozzle and CA while the whole thing is stable.
Don't worry about being too elementary -- as I said, I'm flying blind here, figuring it out as I go. One of the reasons I like posting build threads is that sometimes I'm joyfully driving straight toward a cliff, and someone points out my error before I go over.
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Tim,
I would further reccommend that you get one of Bob Hunts instruction sheets that He publishes with his Lost Foam Jigs, even though you're not using a lost foam jig there is a lot of information in there about installing the formed sheeting and forming the sheeting. Good as Gold info!
Sounds like you're doing things right.
Incidentally you should consider building your next one with a lost foam jig from Bob...you'll never look back if you do!
Randy Cuberly
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Incidentally you should consider building your next one with a lost foam jig from Bob...you'll never look back if you do!
Actually, for my next build I'm planning on getting a set of cores from Bob and building a foam wing.
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Randy has good advice. Have you seen Bob's video (or instructions elsewhere) about sanding the edges of the sheets before sticking them together? One problem I had with edge-glued sheets is that they'd form a ridge that got worse with sanding. I think it's because I squeezed the sheets together too hard. I think it works better if you squeeze them with very little force. Next time I do it I may ask Robby for instruction.
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I always edge-sand sheets before splicing like that. There's no way you can strip them evenly enough with a knife and a straight edge.
For that matter, if you're going to strip off a significant amount from a sheet you should plan on taking a bit more off to straighten things up -- when I whacked the one sheet down the middle, the two 2" wide pieces were bowed by about 1/20".
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I always edge-sand sheets before splicing like that. There's no way you can strip them evenly enough with a knife and a straight edge.
For that matter, if you're going to strip off a significant amount from a sheet you should plan on taking a bit more off to straighten things up -- when I whacked the one sheet down the middle, the two 2" wide pieces were bowed by about 1/20".
Yeah, quarter grain wood seems to be the worst for that. It keeps stress relieving itself for a long time. I always try to use only straight grain consistant wood for spliced sheeting. Much easier to work with. Like the old cowboy said..."Makes for a much more harmonious outcome".
LL~ LL~
Randy Cuberly
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Stuff soaking. I didn't have a tub that long that wasn't a bathtub (and in the wrong building), so I made a frame from furring strips and draped it with plastic. I haven't figured out how to drain it yet without leaving my shop awash -- one thing at a time here. As soon as I get done typing, I'll go see if the wood is flexible enough to wrap around the form.
The water is just hot (well, "really warm") from the tap: hopefully that'll be enough. If you hear swearing from the West in a few minutes, that'll be me, finding out that I didn't soak/heat/whatever enough.
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Oooh, that went well. It's definitely easier to do this part than to make the buck. The picture is the whole mess wrapped in some Vet Wrap that I filched from my wife's horsey first aid kit. Now comes the hard part, and the harder part: figuring how to get the water out of my clever ad-hoc tub, and then waiting until this time tomorrow to see what I have.
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I always edge-sand sheets before splicing like that. There's no way you can strip them evenly enough with a knife and a straight edge.
For that matter, if you're going to strip off a significant amount from a sheet you should plan on taking a bit more off to straighten things up -- when I whacked the one sheet down the middle, the two 2" wide pieces were bowed by about 1/20".
Heres a good tool (jig) for sanding sheeting edges. While back I had made this "gluing trough" (for lack of a better name) to glue up the 3-piece laminated LE's & TE's for Lincoln Log wings. See pics 1 & 2. Its just a shallow channel made from Melamine shelf material,48" long and about 11" wide with the 2 sides an inch high. In use I would make up 2 sets of the LE or TE and put one set up against either side. Then cut a long (24~30") filler piece from 1/4" Masonite material to go between the laminations with a 1/4" or so gap. Then to provide the clamping action, the filler piece is ripped on a long taper to create two opposing wedges, with there outer edges parrallel. (May still have pictures of that if someone is not clear and needs to see it)
Anway, back to the edge sanding. On a later project with foam wings, I needed to prep the edges of lots of sheeting for wing skins when I came up with this minor mod to the gluing trough allowing it to be used in conjunction with the Great Planes sanding bars. The rest of the pictures pretty much tell the story. The 2 sides of the trough had only been screwed (no glue) to the bed, so it was easy to take apart and run it thru the table saw. I just cut a kerf about 1/4" deep the right distance from each side so the sanding bars would sit in the kerf perpendicular to the bed. I use the 2 carpenter squares as a base so the "sanding jig" is at a 45 like a drafting board which makes gravity your friend. The Melamine surface is slick which makes it easy to slide your balsa sheet back and forth. I put one sanding bar (100~120grit) in the groove and resting against the side of trough. The bar has a hole drilled in the middle and I pin it to the bed with 1/4" bolt to fix it from sliding side to side. I place balsa sheet next to the bar, with the jig's bed tilted at 45 gravity keeps it there. I put a second sanding bar (80grit gives good bite) on top of the sheet I am sanding and use the bar as a long handle to slide the workpiece back an forth. The long handle applys even down pressure along the full length of the sheet and this is what produces perfectly straight edges. I have experimented with just using a hand on either end and the result is not as good as with the bar. You do not have to apply any force to the sheet against the sanding bar, just the weight of the sheet and the 2nd bar on top of it is all it takes. And with the slick Melamine surface it takes minimal effort to slide workpiece back and forth. It only takes 7 or 8 strokes on the 120grit bar, then swap out with a 220grit bar for another 4~5 and the edge is perfect. I get invisible glue joints, on both sides of the skins.. I use Titebond or Elmer's carpenter glue, and the masking tape & tent hinge method. The trick there is laying in just the perfect bead of glue, so you get minimal glue squeeze and one quick swipe with damp rag takes care of it. The perfect bead of glue, took a while but I finally figured that out too.
Couple more notes:
1> Some of the sanding bars shown are 44" long. Pretty sure those are no longer available but you can still get the 33" bars which should work fine. Nice to have three but you can get by with just two.
2> In pics 1 & 2 you will see a saw kerf in middle of the trough, disregard that relative to this post. It was part of another tool I was working on and will post about that later when completed. Thread title will be "Ultimate Modeling Table Saw"
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Oooh, that went well. It's definitely easier to do this part than to make the buck. The picture is the whole mess wrapped in some Vet Wrap that I filched from my wife's horsey first aid kit. Now comes the hard part, and the harder part: figuring how to get the water out of my clever ad-hoc tub, and then waiting until this time tomorrow to see what I have.
Tim,
You mentioned waiting until this time tomorrow. Be very careful about unwrapping it too soon. Typically I wait a couple of days to insure that it's very dry. I use Ace bandages and they may be a bit denser than the horsey wraps.
If you unwrap it too soon you will get warps as it finishes drying...Did I mention VERY DRY before unwrapping!!!
Randy Cuberly
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Surprised no one has mentioned the use of strips of old linen sheets to wrap the form with. It will not leave marks like the Ace bandage wrap. But then again it is not Eleatic either.
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Well, I unwrapped the first one today, and got the second one on the buck. Everything looks good on LE #1 -- I often screw up the second time that I try something new: I have my fingers crossed that it won't happen this time.
Tim,
You mentioned waiting until this time tomorrow. Be very careful about unwrapping it too soon. Typically I wait a couple of days to insure that it's very dry. I use Ace bandages and they may be a bit denser than the horsey wraps.
If you unwrap it too soon you will get warps as it finishes drying...Did I mention VERY DRY before unwrapping!!!
I waited until today (two days instead of the one that I originally planned). The wood seems to be as dry as a bone. Moreover, I stuck it on one of the part-built wing panels that I'm throwing out with the shucks taped over it, as a keeper. So hopefully I'm safe.
Surprised no one has mentioned the use of strips of old linen sheets to wrap the form with. It will not leave marks like the Ace bandage wrap. But then again it is not Eleatic either.
I had forgotten the warning about wrapping too tightly, and I know that I was not paying attention to it on the first one. So I was quite happy to see my very first molded wood attempt come out looking good.
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I have 3 fluorescent light fixtures in my basement and they have a plastic cover that goes over the entire fixture. They are 3 inches deep and 4 feet long. I took the best one and filled the two bolt holes with Goop and use that to soak balsa. I've found that room temperature water does the same as warmer water and I soak the wood for an hour or two then wrap it up.
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When I did the lost foam wing for the Latency I built a box using a shelf board for the bottom and some plywood I had laying around for 6 inch tall sides. Lined it with a large leaf trash bag, filled it with water and dropped the balsa in. Room temperature tap water works fine, not sure ho long I let it soak, kept testing to see if seemed flexible enough to form.
All I had was an old sheet, tore 1 to 2 inch strips and used that to wrap the wood on the form. Left it overnight and the next day it was ready to install. I had both forms and did both wing halves in one shot.
Just received a Hunt foam wing for the next one, going to be interesting to see what the difference in weight and performance might be between a foam wing and the existing lost foam wing.
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I don't know if this counts as "nice step-by-step" or "excruciating level of detail".
Gluing on the LG reinforcing ribs. The Legacy makes a strong LG mount in the wing by doubling up three of the wing ribs with 1/16" plywood. Since I got a wing kit and not just a rib set, I got four of the six doublers -- the other two are part of the fuselage doublers and weren't included (I asked them for something weird and they did their best). So the W6 doublers were made by tracing the W6 ribs and hand-cutting.
I don't know if anyone else does this, but for birch plywood up to 1/16", and for poplar plywood ("lite-ply") up to 1/8", I use a utility knife to cut stuff out. You get much better control than with a coping saw, and you only rarely break the blade. You have to be willing to change blades fairly often -- that utility knife that you used 20 years ago to put down linoleum in the kitchen, and haven't changed blades since, will probably not do the job.
The black rods running through the picture are 8mm by 60 inch CF rods from a kite shop that I bought to use as my wing jig. I anticipate them doing an excellent job, unless I accidentally glue them into the ribs.
The circuit board in the background, to the right of the calculator, is a prototype TUT that I'm using for test fitting, to see where I want to install it in the airplane (I'm thinking I'll put it underneath the fuel tank and extend the cowl. If I were to run a piped engine I'd make sure there was insulation between it and the pipe). I don't know if my TUT foolishness will extend beyond recording flights, but if it does I know where TUT, battery, sensor and servos all need to go.
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Just curious about the CF kite rods. What was cost and did you get them locally or order online ?
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Just curious about the CF kite rods. What was cost and did you get them locally or order online ?
I ordered two 60" rods and two 30" rods, and paid around $30. I got them online from some place with "wind" in the name (now, isn't that helpful!).
Edit: https://goodwinds.com/ (https://goodwinds.com/)
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Oop. Eep. Grrr. Hfff hfff hfff.
I just spent twenty minutes of my life, which I will never have access to again, widening the spar notches in these laser cut ribs because they're not quite straight when you put the ribs on a set of jig rods. Out of the 14 ribs on that side, ten of them now have the notches wallered* out; of those perhaps two were unnecessary.
Oh come on! Laser cutting is supposed to be magic! You're supposed to put everything into a bag, give it a good shake, and have a finished airplane fall out, ready to have CA glue run along the joints!
The picture shows the wing with my 1/4" thick straightedge that now slips into the notches. Honestly. I've built die-cut wings that fit better than this.
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* "Wallered" is a highly technical term which, if my investigations are correct, you'll only understand if you're from the deep South, within shouting distance of the Mississippi, or have friends from that part of Oregon that was settled by disgruntled Confederate veterans in the late 19th century.
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I recovered from my hissy fit and glued the spar in. 28 little brass weights (well, most are brass -- I ran out and had to use aluminum in places) hold the ribs vertical, while my trusty straight edge ("borrowed" from my wife's stained glass workshop -- stolen tools work best) hold the spar down.
The rib notches are all a bit shallow, but they appear to be evenly shallow, and there's just enough spar sticking proud of the ribs to sand off nicely.
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I just spent twenty minutes of my life, which I will never have access to again, widening the spar notches in these laser cut ribs because they're not quite straight when you put the ribs on a set of jig rods.
One can make an inaccurate CAD drawing really rapidly. This can then be used to make precisely inaccurate laser-cut parts.
* "Wallered" is a highly technical term which, if my investigations are correct, you'll only understand if you're from the deep South, within shouting distance of the Mississippi, or have friends from that part of Oregon that was settled by disgruntled Confederate veterans in the late 19th century.
The verb to waller among my ethnic Hoosier ancestors refers to something that domestic swine, Sus scrofa domesticus or Sus domesticus, do. The noun form, waller, is where they do it.
Hope this helps.
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One can make an inaccurate CAD drawing really rapidly. This can then be used to make precisely inaccurate laser-cut parts.
I'm just disappointed to find it in a Brodak kit.
The verb to waller among my ethnic Hoosier ancestors refers to something that domestic swine, Sus scrofa domesticus or Sus domesticus, do. The noun form, waller, is where they do it.
It's also a mechanic's term: to waller out a hole is to make it larger in an uncontrolled, sloppy manner.
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Well, since I'm the one who drew the plans, and it wasn't done quickly, I'll add my comments.
The Legacy was designed about 15 years ago, and was first offered with die cut parts. At least several hundred kits were produced, with many being built. I personally built, an still have, one from the early production runs.
I recall no such issues as reported. I'm left wondering if it's only the laser cut kits. I 'm not sure who set up the laser files. I'm sure the files used were the originals. I look at the original files on my computer, and they don't seem to show the issue.
I have not heard of this problem from any of the hundreds of people who have built the Legacy over the past 15 years. I'm not saying that the experiences reported in this post aren't true, just that this is, after all the kits that have been built, the first I've heard of it.
I can say that after the build is completed, you'll have a great flying design, if the one I built, is any indicator.
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I have not heard of this problem from any of the hundreds of people who have built the Legacy over the past 15 years. I'm not saying that the experiences reported in this post aren't true, just that this is, after all the kits that have been built, the first I've heard of it.
I'm wondering if they've recently made changes in the cut files or something. It's enough of an issue that I would have expected to have heard about it if it's been ongoing.
If I can get the lighting right I'll take a picture: I tried this morning and the problem didn't show up at all. It's one of those things that is obvious to the eyeball, but a camera just can't seem to pick it up.
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OK, you should be able to trust the accuracy of laser cut parts. But I always check the rib set before I start the actual building. Its easy to do by stacking the whole set in proper sequence on a couple of short rods, with them all butted together. Its easy to see what needs to be worked on to get a straight set of notches for the spar and LE. Its also a lot easier to dress up the notches while they are stacked together. I will either use the next size smaller square key stock (metal, 12" lengths from hdwe store) with PSA sandpaper or make a custom sanding stick from spruce or bass or hardwood. You are probably going to have even more fun with the LE notches.
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Allan, the spars sweep back from the center, so it would be hard to use a key as you describe. If I were stack-cutting ribs I'd probably cut a narrow notch such that when it was squared up it was in the right place -- but it's too late for that.
The leading edge notches seem to have the same problem as the spar notches, while the trailing edge appears to be mostly straight, for whatever reason.
Correction: the leading edge notches aren't nearly as bad as the spar notches, and may be entirely OK. There's one or two that don't fit, but it may just be a blob of glue from laminating the plywood landing gear braces to the ribs.
I figured out how to take a good picture of this, which was a challenge in itself. Here's the result. I dug a piece of 3/16 x 1/4 out of my stuck, and put a piece of black construction paper behind each notch to enhance contrast (otherwise you'd just look through a notch and see wood on the other side). As you can see, there's definitely alignment issues.
I'm going to share the picture with Brodak: I expect they'll want to know what's going on.
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Tim,
I've seen similar problems with lazer cut kits from another manufacturer in the past. The ribs can be checked by stacking them with the trailing edges all aligned. the center of the spar notches should all line up when that is done. If not the ones that don't line up are the culprits. I usually do this by stacking them and pinning them together with T-pins then laying a straight edge on the spar notches. the ones that are off are obvious and can be corrected at this time with a razor saw.
I realize, of course, that you're beyond that stage now but this is just intended as info for a future build.
I suspect that numerical transformations happen sometimes in the cut files and if no one test builds a kit they go unnoticed until some body like you complains...good for you. I've always just invented some new words for the engish language and moved on...better to let the makers of the kit aware.
Don't forget to shim those empty spaces between the ribs and the spars, or a weaker wing will result in torsion...as I'm sure you know! Don't force anything however or warps will result when it comes off the jig.
Randy Cuberly
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...better to let the makers of the kit aware.
This is my first build of a Brodak product, but with their reputation I figured I'd be doing them a disservice to keep my mouth shut -- even without the fact that I'm flapping it here.
I hear you on checking. It just didn't occur to me, because laser cut kit are just perfect, right?
It would be interesting to know if the problem is in the cut file or the CAD file -- this is the sort of thing that might happen if someone rearranged the ribs for the cut files for some reason or another and didn't pick them up correctly for the move.
Ah well, I'm just going to move on and build the wing. And maybe check the fuselage pieces for fit as early in the process as possible...
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With practice, I got it down to four or five ribs whose notches needed shaving. I think the spars are a bit bowed, but as long as I'm not hammering them into place, I'm happy.
Bottom spars installed, the top halves of the gravetonic clamps are in place, and the glue is drying for the evening.
I think I can get away with deepening just two or three LE notches, and sanding the corresponding ribs so they don't stand proud of their neighbors. If there are any ribs that just don't reach the sheeting I'll either glue some 1/32" balsa on and sand it down, or I'll glue extenders on the sides of the ribs.
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Definitely not much progress in the last couple of days -- but I have gotten lots of paying work done, which has to count for something.
LG blocks in place.
This has two deviations from the instructions, one of which is my fault, both of which can be seen in the photo.
The one that's my fault is that I put the rib in with the plywood reinforcing pointing the wrong way. I very carefully made all the reinforced ribs mirror images of each other, then went and put the most important ones in backwards. Stay tuned -- perhaps the leadouts will come out of the center of the rudder.
The one that's sorta not my fault is that the jig rods interfere with the location of the LG block. The directions want you to glue up the blocks, then drill, then install in the wing. This cannot be done if you're building with a jig. I don't see this as an issue -- I'll just drill these after the fact, probably by making a cradle for my drill press table.
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Brodak sells wing rib kits for all their models, and I've used many sets on my own-design models instead of cutting my own.
I have never had a problem with either the wood or the laser cutting.
Also, I built a Brodak Legacy a long time ago, and I don't remember any trouble with the parts.
Floyd
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Floyd, I was pretty astonished. Frankly, the reason I went to the trouble of taking the picture was because I didn't think it was fair to ask people to believe me without some sort of at least semi-independent evidence.
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I ended up not deepening any LE notches. I did two things, the first probably smarter than the second. The first side I just let the LE be straight, and then I came back later and put in shims where it didn't quite reach the notches. Three or four ribs were affected. On the second, I forced the LE a bit. This put a 1/16" deep wow in the LE, which I then went back and shimmed up with a balsa strip, sanded down flat. It'll leave some stresses (hence, not so good), but I think that once the LE sheet is on it won't mess the wing up.
To bring the ribs out to the sheeting, I'm going to shim it. I can't quite bend 1/16" balsa along the grain to match the rib, so I soaked some balsa and bent it on "Bertha", my antique soldering iron that I inherited from a radio-amateur uncle. The pictures are of the bent wood being held up against ribs to dry, and Bertha.
Balsa wood is astonishingly easy to bend if you use a bit of heat. I use the shank of Bertha (not the tip!) which is probably a bit hot. Get the wood wet -- it doesn't have to soak for long -- then tug on the ends while pulling it down over the iron. It'll buckle if you don't keep some tension on it and give it time (I think that's because the wood in contact with the iron gets hot and pliable first; keeping a pull on it makes the bend want to happen by stretching the outside fibers, and waiting gives the outside a chance to get hot). I've never tried wood thicker than 1/16", but it's great for Bostonian-sized airplanes.
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I just spent my last four building sessions custom-bending some wood so that I could glue shims onto the tops of about a dozen wing ribs, then slicing and gluing said shims, so that I could then sand most of the shim away, all so that, in the end, I could get a fit between the ribs and the leading edge sheeting that pleased me.
And, to top it all off, I was making sly innuendos about Howard Rush's sanity earlier today.
I don't think I should be allowed to build kits anymore. I think my relatives need to be trained and supplied, and whenever I start making "I'm going to build a kit" noises, they should grab a box of contest balsa, open it, and say "here Tim, sniff this".
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Tim is a fellow stunt flyer and if he say's he had a bad kit - he had a bad kit and that's all their is to it!!
ALL manufacturers occasionally make lemons. If you make thousands of ANYTHING-sooner or later you will make a turkey. Nikon is having one of the roughest periods of quality control I have seen. I just got another recall notice on My Toyota truck-this time for the driver side airbags,(last time it was the front ball joints).
Hey, his kit sucked- he worked it out,(because he's experienced) and he's back on it. Way to go Tim. y1
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I've spent the last week balanced between being sick (nasty cold, nothing worse), using my airplane-related time for TUT building, and dithering over doing the next step with molded leading edges (since I've never done this before!)
So I finally got around to marking and trimming my leading edge sheet, figuring out how to clamp it (which may or may not be the best way -- more on that later), then actually gluing it and clamping it.
I decided I'd use rubber-band clamps. To keep the bands from digging into the sheet, I used bits of 1/64" plywood wrapped around the LE.
The clamps are rubber bands tied to bits of balsa (spare spar sections), then pulled around the LE and hooked over the stick on the top. This works best if you have something to reach in and grab the rubber band -- which, since I like using rubber bands for clamps, I have.
When I cut the foam buck for the LE I rushed things going around the LE curve. As a result, my buck had a sag in the middle of it. I mostly dealt with this by sanding the ends, but there was still enough built into my leading edges that when the ends are held tight against the ribs & spar, there's a gap. To deal with this, I used tape between every rib bay where I didn't have a rubber-band clamp. That holds the LE sheeting nicely against the spar.
In retrospect, I may have been able to use tape for the whole thing -- I don't think I would have a better clamping job, but I might have saved some time.
Now it's sitting out in my shop, well weighted down, verified straight, and with the glue drying. Tomorrow I'll have something much more like a wing than I do today.
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Someone pointed out via PM that I should have put the trailing edges on (thanks!). Yes, I should have -- I got so anxious about this step, that I forgot some intervening ones. So, I guess the next thing to do is put on the trailing edges, correct any problems on the inboard wing from having the LE put on first, and then go back to installing the leading edge on the outboard wing.
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Hey Tim, I'm building an RSM kit (sorta) and it also has it's issues. I'm having fun, though.
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Randy Powell is building a kit? I am stunned.
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I think the only kit I've ever built that didn't have some fairly serious issues was my Collussus from Walter Umland. That was truly a fabulous kit. Everything fit and went together exactly as it was supposed to, and the wood was obviously very carefully selected for it's intended job.
All the kits I've built from other suppliers have had some issues. Most were certainly not show stoppers but serious enough to delay construction significantly and require modification. I've had kits with parts missing, holes in wrong places in ribs, supplied balsa that was too thick or too thin for the task at hand (not to the plans), balsa that was warped and twisted so bad it couldn't possibly be used, lazer cut parts that didn't come close to matching the plans, even a pair of fuselage sides that were 2.5 inches shorter than on the plans.
I usually wind up substituting about 25% of the wood for being too heavy or the wrong type for the required job. Probably the most common error is fuselage formers that are not wide enough to space the required engine, requiring all new fuselage formers to be traced and cut larger.
I have and have built a lot of kits over the years and just about every time I do I say "never again". The exception is the kit I mentioned above. Its the only kit I've built from Walter but anytime he makes something I want to build I will have it!
I do realize that making kits is not an easy task and certainly not one that pays very well. I also do believe that most of the folks that make kits could do better.
I do not believe in singleing out any individual for criticism...trust me they know who they are. I do believe in singleing out those who deserve praise and Walter is the one that gets that vote. I only wish he would build more large stunters that are competitive in todays expert environment.
Randy Cuberly
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The directions say to sand the leading edge to final taper by putting it between a 3/8" rod and a 3/16" rod -- to get a piece of balsa that tapers from 3/8" to 3/16. That wouldn't happen -- you'd get something tapered from less than 3/8 to more than 3/16. I could do it that way, then at the end shrug and sand the ribs a bit narrower -- but nooooo, I'm going to do it "perfect" -- or at least I'm going to get a lot closer.
I ended up fumbling around with rods (7/16 and 3/16) and spacers, to get a TE that's pretty close, although still a bit big on the wide end. I'll sand it nice once it's glued on.
Here's some CAD drawings showing what you get from using the directions, and what you need to do if you start with a 1/2" rod, a 1/8" rod, and some magic spacers that just happen to be the correct width.
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I have found that using square brass channels (at the K&S rack) work better than rods for that procedure. 8)
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I have found that using square brass channels (at the K&S rack) work better than rods for that procedure. 8)
I considered that. I didn't do it because (1) it fixes the problem at the big end but not so much the small end, and (2) I didn't want to drive to the hobby shop!
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I always thought that you required three rods to avoid building in a warp.
The leading edge stays constant, while the trailing edge requires two sizes?
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I always thought that you required three rods to avoid building in a warp.
The leading edge stays constant, while the trailing edge requires two sizes?
Yup. I did the calculation for both sizes for the "this won't work quite right" example, but not for the "this is how to do it" example.
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Yep, have to use 3 rods. I use soft steel rods from the hardware store so they can easily be bent to conform to the trailing edge.
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If you have a table saw you can make you own sanding guides from hardwood sticks. You can sand the same taper into the guide sticks and that eliminates the errors of the rods. With each use of shaping a new balsa surface I put a new layer of masking tape on the sticks as a guide to sand just down to but not into the hardwood guides.
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If I'd had a table saw I probably would have tried that, or perhaps just whacking what I needed out of the wood that I had, then doing final sanding for smoothness.
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If I'd had a table saw I probably would have tried that, or perhaps just whacking what I needed out of the wood that I had, then doing final sanding for smoothness.
Tim,
I think the most important thing here is just maintaining a consistent radius for the LE. A couple of small radius forms (on sheet) and your eyeball (which is surprisingly accurate if you're careful) can do a really good job.
Randy Cuberly
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Randy Powell is building a kit? I am stunned.
Hi Bill,
I am sure you are aware that Randy is not really building a kit. He is using some parts from a kit, a set of Imitation foam wings and some parts Pat J cut for him. So, no, he is not truly building a kit. ;D
BIG Bear
RNMM/AMM
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I think the most important thing here is just maintaining a consistent radius for the LE.
We're talking about the trailing edge at the moment, which I forgot to put on before I put on the leading edge. So the build order for this one is inboard LE, TE in & out, then outboard LE.
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We're talking about the trailing edge at the moment, which I forgot to put on before I put on the leading edge. So the build order for this one is inboard LE, TE in & out, then outboard LE.
My mistake, when I read about using rod method for tapering, I thought you were talking about flaps or elevator.
For tapering a stick to make TE's, I do that on a table saw also..
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We're talking about the trailing edge at the moment, which I forgot to put on before I put on the leading edge. So the build order for this one is inboard LE, TE in & out, then outboard LE.
Oh, of course. Well just modify the build a bit and install the trailing edge sheeting, then sand the back of the TE ribs flat and install a cap, then sand the necessary taper into the cap to comply with the sheeting angle.
I don't believe in tapering flaps for a stunter...it tends to make them too wimpy. With flaps, the stiffer the better. I usually cover my flaps with two layers of 1 OZ fiberglass cloth also. makes them very stiff and really helps in the trimming process as well as making the airplane hold trim better.
Randy Cuberly
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With flaps, the stiffer the better.
The JCT is coming to town.
We're plenty stiff from the flaps on down.
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I don't believe in tapering flaps for a stunter...it tends to make them too wimpy. With flaps, the stiffer the better.
http://flyinglines.org/dirt.5.09.html (http://flyinglines.org/dirt.5.09.html). Search for "flap", read about the flaps on Howard Rush's Impact at the Regionals that year.
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The first shot is just a trophy shot -- I got the outside sheeted! Moreover, I was smart enough to fold the ends of my tape over this time -- it came off much easier, without me worrying about digging my fingernails into my nice smooth leading edge.
In the process of sheeting the outside, I realized that some of the glue had let loose where I spliced my sheets together, leading to a crease in the LE sheeting. I think I was being a bit too economical with the Ambroid, and the stress of the balsa shrinking as it dried pulled things apart. I was able to mostly correct this on the outside -- but then I discovered that I had the same problem (in roughly the same place!) on the inside LE sheeting, and since that was all glued down in happy ignorance, there's this honkin' big crease sticking out on that side. So I backed up the crease with little 1" wide strips of 1/16" balsa, in hopes that when I sand the crease away the LE will have enough structure back there that it won't get too warped up.
Sigh. Screwing up already. Oh joy.
The second shot shows a nifty way I figured out of holding up a wing, if you happen to have a leading edge buck shuck* lying around. Not apparent in the picture is the fact that there's about half a pound of steel bar on the wing tip end, holding everything steady. This holder came in handy for gluing in the afore-mentioned backup strips.
* Say that three times fast.
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Shouldn't this be in the building thread?
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Shouldn't this be in the building thread?
If you mean the Building Techniques forum -- I dunno. I always took that to be a place to ask questions about how to do something, or post nifty new ways to do something.
This is just a story of a particular build.
I figure that if it's in the wrong place, some moderator or another will move it, and if I'm lucky I'll remember the right place to put my next build thread.
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Man, you are so easy.....
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Hi Bill,
I am sure you are aware that Randy is not really building a kit. He is using some parts from a kit, a set of Imitation foam wings and some parts Pat J cut for him. So, no, he is not truly building a kit. ;D
BIG Bear
RNMM/AMM
Hello Bill, yeah I was just having a little fun with that. Always enjoyed his builds when he did them back in the day over on SSW.
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Tim,
Do you use masking tape when you edge glue the sheeting? Also I like SIGMENT for edge glueing sheeting because it doesn't shrink as much as Ambroid when it dries.
I use the masking tape method and have never had a problem like you show!
Randy Cuberly
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Tim,
Do you use masking tape when you edge glue the sheeting? Also I like SIGMENT for edge glueing sheeting because it doesn't shrink as much as Ambroid when it dries.
I use the masking tape method and have never had a problem like you show!
Randy Cuberly
Hey Randy:
I usually use the masking tape method, but I was seeing if I could improve on it this time. I don't think my problem was using Ambroid -- it was using Ambroid that was thinned out too much to really work.
Live & learn.
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I've been flattened by a cold the last couple of weeks, so I haven't gotten much time for fun work, and even less for taking pictures.
The TE wood was, not unexpectedly, bowed. Balsa warps. You should never expect a sheet to be straight. In this case the worst sheet was bowed by a hair less than 1/8", so I sliced a nominal 1/8" off of each sheet, leaving me with sheets 1 3/8" at the ends and nearly 1 1/2" in the middle. They're glued on so that the straight edge faces in to the wing, and the bowed edge lops over the trailing edge wood, to be trimmed off.
I couldn't get the TE to match the rib taper exactly, and the more I tried the more I messed up the ribs. So I gave up and just clamped the @#$% out of the TE. It'll have a wow in it, which I'll mostly sand off, and for the rest -- I'll weep if I lose a contest that gets down to the appearance points.
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Today's work was whacking a bellcrank out of 1/8" phenolic, and making a pivot. This will all run on a hunk of 5/32" drill rod, set into the wing per the plans.
The throws indicated on the plans seem wacky to me -- they're calling out using the inner pivot on a Brodack bellcrank (5/8" from center) to a flap horn that's 1.25" from center, and thence to an elevator horn that's less than 1/2" from center. That just doesn't seem right. I'm going to set it up so that the flaps move +/- 30 degrees or so with +/- 45 degrees bellcrank movement, and the elevator having, presumably, more (it'll be adjustable, so it'll be whatever I want in the end).
If I stick with the flap horn dimensions given on the plan, that works out to a bellcrank pivot that's 7/8" from center, which eyeballs out to about the right distance.
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Phenolic sheet is just awesome stuff to have around if you have a bunch of sharp sandpaper that you want to be dull. It's pretty much just as good as fiberglass and carbon fiber for taking that raspy edge off your sandpaper and leaving smooth dullness behind.
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Today's work was whacking a bellcrank out of 1/8" phenolic, and making a pivot. This will all run on a hunk of 5/32" drill rod, set into the wing per the plans.
The throws indicated on the plans seem wacky to me -- they're calling out using the inner pivot on a Brodack bellcrank (5/8" from center) to a flap horn that's 1.25" from center, and thence to an elevator horn that's less than 1/2" from center. That just doesn't seem right. I'm going to set it up so that the flaps move +/- 30 degrees or so with +/- 45 degrees bellcrank movement, and the elevator having, presumably, more (it'll be adjustable, so it'll be whatever I want in the end).
If I stick with the flap horn dimensions given on the plan, that works out to a bellcrank pivot that's 7/8" from center, which eyeballs out to about the right distance.
I'd calculate the throws. I'd also move the bellcrank more to get more leverage over the flaps.
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Phenolic sheet is just awesome stuff to have around if you have a bunch of sharp sandpaper that you want to be dull. It's pretty much just as good as fiberglass and carbon fiber for taking that raspy edge off your sandpaper and leaving smooth dullness behind.
Could be a warning that it will put similar wear on things that go in the holes.
Speaking of phenolic, remind me to tell you the story of the phenolic motor mount pads, the serpents, the Sheriff, and the convicts.
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I'd calculate the throws. I'd also move the bellcrank more to get more leverage over the flaps.
I'm going to calculate throws. I'm also going to measure the actual movement I get from the bellcrank once it's in the wing, and, if necessary, re-think the flap arm length.
Could be a warning that it will put similar wear on things that go in the holes.
Phenolic is a pretty popular bearing material amongst mechanical engineers, so I'm pretty comfortable that it'll be OK. And the only places where there'll be working metal-phenolic joints is at the leadouts: the BC hinge is aluminum against drill rod, and the BC to pushrod join will be a ball joint.
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I'd calculate the throws. I'd also move the bellcrank more to get more leverage over the flaps.
If I make the flap arm 1.5", it should still fit well in the fuselage, and the flaps should move through about thirty degrees for 120 degrees of bellcrank movement. I ought to be able to get that much (and it ought to be more than necessary).
Dogleg is calculated. Oddly, but it works. I only went as far as calculating flap rotation vs. bellcrank, because your spreadsheet doesn't work for me, so I'm whomping it all up with Scilab. I'm assuming that leadouts & flap to elevator linkage will take care of itself. I may do better before the control system actually goes in.
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Dogleg is calculated. Oddly, but it works. I only went as far as calculating flap rotation vs. bellcrank, because your spreadsheet doesn't work for me, so I'm whomping it all up with Scilab.
What matters is leadout travel vs. control surface deflection and d surface / d leadout.
Tim is a computational elitist and eschews ciphering done with common tools like Excel.
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Tim is a computational elitist and eschews ciphering done with common tools like Excel.
I don't find Excel scripts to be user friendly.
The Atomic Zombie Workshop could use a page that would do this, user friendlilly.
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What matters is leadout travel vs. control surface deflection and d surface / d leadout.
I know. I should do that calculation, too. At the moment I'm telling myself that if it's semi-trickle from bellcrank to flap, then because everything else is semi-trickle and all in one plane, it's semi-trickle everywhere else.
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If I make the flap arm 1.5", it should still fit well in the fuselage, and the flaps should move through about thirty degrees for 120 degrees of bellcrank movement.
120° bellcrank movement ??? You previously said +/- 45° which sounds normal.
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Howard said I should design for more. If the bellcrank moves +/-60 to give +/-30 at the flaps, then in normal flying it should never get beyond +/-45, with plenty or headroom.
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I usually install a hard stop to limit crank to +/-45. I think round maneuvers require 5-10° control surface deflection and the corners 20-25°.
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I usually install a hard stop to limit crank to +/-45. I think round maneuvers require 5-10° control surface deflection and the corners 20-25°.
I prefer to insure that the controls will freely move well beyond anything "reasonable" without binding. I haven't felt motivated to put in a hard stop, but if I did it would be at around +/- 60 degrees, and it would just be there to make sure that the controls don't go someplace where they can't be retrieved.
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Actually cut (and bent, and soldered) some metal!
I'm going to do Walker-style tweakable flaps, which means that you need individual flap horns. This, in turn, means that the flap horns need to be accurate and stout.
So the flap horns are bent from 1/8" music wire so that -- hopefully at least -- they won't get tweaked by accident. Rather than just soldering the wire to a hole in the horn, I bent the wire itself, to give the horn more surface area and far more moment arm to work on the wire. They've got two hinge tubes on each wire so I can space the hinge tubes as far apart as possible for rigidity. The top two pictures show the result.
I was concerned about getting all the angles right -- the control arms need to be perpendicular to the plane of the flap arms, even while being offset about an inch and a half. Rather than try to get it all right "floating on air", I made a jig from a bit of 2x4. The jig holds everything in alignment while I'm soldering it all together.
When I get to the point of making the control rods, there'll be a single rod from the bellcrank to the flap control hole on the left horn, and a rod from the left horn back to the elevator. There'll be a boss on the elevator rod with a screw going to the right flap, set up so that turning the screw tweaks the right flap with respect to the left flap & elevator. Alan Resinger has an excellent picture somewhere around here showing how he did his -- I'll be copying that. The only thing that (to my knowledge) I'm really doing different from Alan and Paul is that they put their adjustment on the left, where mine is on the right because I'll be running a muffled slimer, and I don't like the thought of all that oil dribbling inside my nice clean fuselage.
Done right there should be a discrete little hole behind the right wing into which I can reach with a nice long ball-end hex driver and adjust the flaps.
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Quote:
<<<There'll be a boss on the elevator rod with a screw going to the right flap, set up so that turning the screw tweaks the right flap with respect to the left flap & elevator. Alan Resinger has an excellent picture somewhere around here showing how he did his -- I'll be copying that.>>>
Tim or Alan Resinger: Would like very much to see picture of that if you can locate.
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Tim or Alan Resinger: Would like very much to see picture of that if you can locate.
Try this thread: http://stunthanger.com/smf/index.php/topic,24567.0.html (http://stunthanger.com/smf/index.php/topic,24567.0.html)
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There will be a complete article on it in a near future Stunt News.
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There will be a complete article on it in a near future Stunt News.
So, about the time I finish making all the mistakes on this one and button up the fuselage?
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I realized after I got my individual horns built, that whereas a normal flap horn is rigid across it's length, these two flap horns had a significant chance of independently flapping (as it were) around when they were supposed to be holding still. Rather than just putting mounting tabs on each one and depending on my nice light soft trailing edge to hold them in some sort of alignment, I decided that they really needed to be nailed down to a common axis.
I don't know if this is right, or if it's what the big boys do, but it seems like a good idea to me. I just soldered a length of 1/8" music wire to the pivot tubes; I'll gouge a slot in the trailing edge to accept the wire, and life should be wonderful.
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Here's the horns glued into the trailing edge. I angled the crossbar down inside the TE so that I would get full travel -- I figured 30o or more would be enough, and I have discernibly more than that, so I'm happy.
This is all pursuant to getting the bellcrank installed, for which I need to accurately determine the amount of bellcrank tilt I need to make the ball link happy, for which I need to have the horns installed, at least temporarily -- and I can install them for permanent now, so I did.
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Control system in.
This required much hacking up of ribs for clearance, including removing and reinstalling some of the shear webs mentioned above. If I were smart I would have installed every other shear web with the thing in the jig -- this would have made it nice and rigid in torsion, while still leaving me with lots of room for cutting ribs apart in situ.
Not shown is the fact that I was a bit stingy with the amount of bellcrank mount that extends out the bottom of the wing. I'll probably put a bit of extra plywood bracing on the sheeting on the inside, to help transfer the flight load to the outside of the sheeting, to be picked up by the bellcrank pivot brace that transfers the load to the fuselage.
I get to work on this thing in mostly short chunks. As a consequence, I often end up doing things out of order, or at least in strange orders. But it's either that or not get it done at all, so I just kinda proceed in all directions at once, and sooner or later a plane comes out.
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Tim,
I don't know what your plan is but, that thing is going to roll real fast with the flaps in that position! y1
Might need a bit more reinforcement..... LL~ LL~ LL~
Jerry
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I don't know what your plan is but, that thing is going to roll real fast with the flaps in that position! y1
The elevator pushrod will tie it all together, and allow me to tweak the flaps precisely with a long hex wrench instead of the "bend a little, hope a little" method.
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Totally useless trophy shot of the center section -- but, it's all sheeted!
I didn't quite match the height of the TE sheeting with the center section sheeting, so I'll be doing some filling before the CF veil goes on -- my bad, I need to figure out how to do the job right.
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Totally useless trophy shot of the center section -- but, it's all sheeted!
I didn't quite match the height of the TE sheeting with the center section sheeting, so I'll be doing some filling before the CF veil goes on -- my bad, I need to figure out how to do the job right.
Filler???? It looks like some sandpaper will do the job. Why add weight?
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There's a couple of hard-to-photograph spots where TE sheeting dips down about 20 mils. That seems a lot to take off from 1/16 inch.
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Filler???? It looks like some sandpaper will do the job. Why add weight?
How thin would you let things get in that area, on that big a plane?
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Yeah, 100grit will make short work. LL~ LL~ LL~
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Hey Tim...
At this stage it doesn't look like it would be too much trouble to replace that piece of sheeting with 3/32 and then sand that down to blend with the other sheeting and the Trailing edge sheeting. That's what I would do. I don't think filling it with fillet material or anythin else suitable will be easy and will probably never look quite right...at least that's been my experience with trying to do something like that in the past.
As for sanding the trailing edge sheeting I doubt you'll get it to blend with the rest of the trailing properly. There will be a dip at the point it starts getting thinner even if it is gradual.
Just my two cents!
UUUhhhhhh....I just reread what you said above and guess I'm not clear on what is thinner the trailing edge sheeting or the center sheeting. What I said above obviously applies to the center sheeting being thinner. If it is the other way around then I would agree with Paul...just sand the center sheeting to blend with the trailing edge. No real loss of strength there. The spars are the real load carriers.
Besides, you did put verticle grain supports in the front edge of the trailing edge sheeting...Right?...
Randy Cuberly
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I think at this point I'm just going to do my best with filler and move on. That's not the best solution, but I'd like to have this plane done before the end of the 2015 competition season and even if it turns out a bit ragged it's certainly going to be better than the Twister that I'm flying now.
It would be nice to know how to avoid this problem in the future -- the only really positive way I can think of, barring making a miniature set of tongue & groove routers, is to put a bit of 1/32" sheeting behind the TE (and LE, too, probably) sheeting to maintain the same level. Either that or I just had a slightly too-tight fit on the sheeting and it kinda dragged the other sheeting along with it.
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I think at this point I'm just going to do my best with filler and move on. That's not the best solution, but I'd like to have this plane done before the end of the 2015 competition season and even if it turns out a bit ragged it's certainly going to be better than the Twister that I'm flying now.
It would be nice to know how to avoid this problem in the future -- the only really positive way I can think of, barring making a miniature set of tongue & groove routers, is to put a bit of 1/32" sheeting behind the TE (and LE, too, probably) sheeting to maintain the same level. Either that or I just had a slightly too-tight fit on the sheeting and it kinda dragged the other sheeting along with it.
One problem I have found is that no two pieces of balsa are "exactly" the same thickness. That could be your problem. The center sheeting might be thicker than the TE piece. I make an effort to pick all my sheets and make sure they are the same. I have a planer to deal with the sheets that are too thick!
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One problem I have found is that no two pieces of balsa are "exactly" the same thickness. That could be your problem. The center sheeting might be thicker than the TE piece. I make an effort to pick all my sheets and make sure they are the same. I have a planer to deal with the sheets that are too thick!
I have that issue, too -- this isn't it. What I'm complaining about is a spot where the TE sheeting sags a bit between a pair of ribs (Mike Haverly is going to get on and ding me for not putting shear webs on the TE in the center section -- he's right).
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AAAhhh, yeah!
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If I remember the next time I build a wing I'm going to get some nice soft balsa and I'm going to put the shear webs for the TE in before I put on the sheeting. I might even make up one continuous web for each side with deep notches, and matching notches in the ribs. I'll design the whole thing to stand a bit proud of the ribs (hence the soft balsa), and then sand it down to match the ribs before putting on flawless -- flawless -- TE sheeting.
If I succeed at that, knowing me, there will be something else in the plane to be totally atrocious. My building seems to operate on a principle that the aggregate severity of screwups is conserved -- I only get to move them around, not make them go away entirely.
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If I remember the next time I build a wing I'm going to get some nice soft balsa and I'm going to put the shear webs for the TE in before I put on the sheeting. I might even make up one continuous web for each side with deep notches, and matching notches in the ribs. I'll design the whole thing to stand a bit proud of the ribs (hence the soft balsa), and then sand it down to match the ribs before putting on flawless -- flawless -- TE sheeting.
If I succeed at that, knowing me, there will be something else in the plane to be totally atrocious. My building seems to operate on a principle that the aggregate severity of screwups is conserved -- I only get to move them around, not make them go away entirely.
The way you've described is maybe the best but not really necessary unless you intend to finish the wing in transparent covering.
Look at the picture of the Nobler wing I put in my post above. cutting the cross grain sheeting a little shy of the outside edges of the trailing edge and simply glueing it to the inside edges with CA actually works about as well structurally. I've done it both ways and never had a problem with either. I would say that it's very easy to screw up the sanding operation you describe and get things out of kilter on the ribs if the task isn't done very carefully. The method shown in the post is much easier to do!
Randy Cuberly
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The way you've described is maybe the best but not really necessary unless you intend to finish the wing in transparent covering.
Look at the picture of the Nobler wing I put in my post above. cutting the cross grain sheeting a little shy of the outside edges of the trailing edge and simply glueing it to the inside edges with CA actually works about as well structurally. I've done it both ways and never had a problem with either. I would say that it's very easy to screw up the sanding operation you describe and get things out of kilter on the ribs if the task isn't done very carefully. The method shown in the post is much easier to do!
It occurs to me that if I cut the webs just a hair smaller than they'd need to fit inside the TE, I may not have perfect control of how deep they set inside but they'll still do their intended job. I'll probably go back and do the TE right before I get too much farther along.
I was able to slit the TE sheeting and pull it up in a couple of places. This alleviates the wow, but still leaves a bit to be desired. Oh well -- this is better than what I'm flying now, and the next one should be better yet.
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If you watch any of Bobby Hunts videos you may have seen how he does it. He made a jig to cut the web pieces and then fits each on. Just did that on my latest stunt fun machine. Sure makes for a stiff trailing edge.
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Spinning off into wackiness for a moment, here's the ongoing effort to add an electronics bay to the wing. This is for a TUT, which at a minimum will be used to record flights, and if things work out, may add some helpful engine-control features.
I should have done all of this before the top sheeting went in -- the reason I didn't was primarily due to forgetfulness! Late is better than never. Hopefully I'm not adding too much weight. The extra hole you see in the front of the wing is because the first time I drilled everything I was not correctly visualizing where the bellcrank was. Asking the bellcrank to pass through a piece of balsa is Not Good. The actual conduit location is above the bellcrank; it's well out of the way, and having a conduit means that there won't be any dangling wires to get entangled with the bellcrank.
The electronics bay is in the last sheeted bay on the outside of the wing, and communicates with the tank compartment of the stunter with a conduit that's formed from 1/32" balsa, molded around a carved former. The conduit should be just big enough to let me slide a connector in from the outside.
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More fun with the electronics bay. I've used up something like 72 square inches of lite ply to get a hatch cover that uses about 18 -- the rest are all false starts, screwups, and the like.
But, I now have all the electronic bits I need to support a TUT all tucked away into the outboard wing where they'll be out of the way of the control system and where the weight might do some good. Much of the agony was trying to make a super-duper one size fits all box that would attach with the hatch cover and hold TUT, battery, and regulator. I finally ended up with a hatch cover that holds the TUT (something needs to hold the TUT rigidly, or the accelerometer and gyro readings won't make sense), and I just stuffed the rest of the electronics in between the wing ribs. Which is what I should have done from the start...
I did find a nifty way to make a hatch cover that you don't have to pry out with your fingernails. The hatch cover will need to come off any time the TUT is being talked to, or when I need to take the battery out for recharging; I didn't want to mar up my finish. So I put a magnet on the TUT carrier and a magnet in the hatch cover, oriented so they oppose one another. As long as the hatch cover isn't stuck it floats right out of the hole.
The last picture in the series shows the magnets being glued in. I routed holes in the two bits of plywood, and epoxied the magnets in. I always get magnets and such backwards from how I want, so I was careful in how I jigged this up. I started with a magnet underneath the TUT carrier. That forced the magnet in the TUT carrier to orient with the first magnet, and held it at the bottom of its hole. It's embedded in epoxy. Then there was a piece of waxed paper, with the plywood for the hatch cover laid out upside down on top. This means that the magnet in the hatch cover will attract when the hatch cover is upside down -- and repel when it's right side up. Finally, I topped the whole thing off with more waxed paper, a scrap of wood, and a magnet to hold the wood down and give me a nice flat surface.
If you're flying in the Pacific Northwest late this year, you'll know my plane -- it'll be the one with a dot of iron filings on the outboard wing, just outside of the fuselage.
http://youtu.be/vqxhgp0j5vc (http://youtu.be/vqxhgp0j5vc)
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I suggest you seal the conduit with tape or something: 1) to keep oil out and 2) to keep the hatch from blowing off.
Edit: Oh, now I see how you used the magnets. Sorry, Tim. Once again I underestimated your cleverness and weirdness. Couldn't you have achieved the same repulsive force with less mass with a foam peanut?
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Will the magnets scramble something in the electronics? Over time.
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I suggest you seal the conduit with tape or something: 1) to keep oil out and 2) to keep the hatch from blowing off.
Thank you. I'll have to think about how that might be accomplished without weighing a ton. There'll be wires going through it, so just tape won't seal much at all.
Will the magnets scramble something in the electronics? Over time.
There's nothing in the TUT that's sensitive to magnetic fields, at least that I know of. Strong magnets and hard drives, or strong magnets and credit cards, don't go together well -- but I think I'll be fine.
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Clever hatch. Not sure about the path, but hey, if it's crazy and it works, it's not crazy.
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Clever hatch. Not sure about the path, but hey, if it's crazy and it works, it's not crazy.
I will be advancing science, if nothing else. Next up in the build is to design the circuit board to make a micro servo into an Auntie servo so that I can record elevator deflection in flight. Test Pig #3 has an Auntie servo but it's an old full size Royal that I used because it let cobble together a circuit by hand -- to get the size & weight down I need to have a board made that'll use surface-mount components.
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I got Auntie Servo mounted in the wing, I need to get the linkage to the thing in and pictures taken.
The absolute latest work was getting Auntie Servo's schematic into CAD and getting a PC board made and shipped off. The first Auntie Servo was cobbled together from through-hole parts, but that won't fit into a miniature servo -- the one for which parts are on order will be 9mm x 12mm, and will fit nicely inside a "9gm" micro servo.
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Auntie Servo, waiting on linkage. This is the top of the wing, so I need to get everything sorted before I start messing with the fuselage. There'll be a rod from Auntie Servo back to the outside flap control horn; that plus some hand calibration should tell me all I need to know about where the controls are on any given flight.
Edit: Things always work better when you actually remember to include the pictures.
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Linkage installed and working. Auntie Servo will be doing her job.
Everything is just taped together at the moment -- I'm about to go back out and apply some epoxy to the joints. I'm usually very leery of metal-to-plastic bonds, but there's practically no force on these.
https://youtu.be/3Pks8JmxP50 (https://youtu.be/3Pks8JmxP50)
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Back to normal CL stunt stuff. Making the flap pockets. The Brodak kit has you glue a piece made out of 1/8" plywood to the end-grain of your flap. I didn't feel that was going to be strong enough, so I made up some bits out of 1/16" balsa and inlaid them into the ends of the flaps, then glued 1/16" plywood end caps on. It's probably overkill, but it should be enough to tweak the flaps with, which means that it's more than enough to hold things together in the air.
The inlaid pieces are put in with gap-filling CA, the end plates are epoxied with 30-minute. It should all be stout enough.
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Except that now I have to wait for the epoxy to cure. If I had some of this http://www.masterbond.com/newsrelease/led401 (http://www.masterbond.com/newsrelease/led401) then I'd be on to the next step!!!
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Pretty cool!
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Update on the flap pockets: in retrospect, I should have glued the plates in with some sort of spacer in the hole, to make sure they were spaced correctly. I didn't, and I ended up filing the ends of my flap horns a bit so they'd slip into the boxes. Next time. If I remember.
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At the Tune Up this past weekend Paul pulled me aside to discuss my flap mechanics. It turns out the pockets & whatnot are both overkill and insufficient. But I've figured out what to do, Paul has approved, and next time it'll be WAY EASIER.
In the mean time, here are Aunty Servo's brains, courtesy of the Atomic Zombie Workshop.
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Tips tips tips.
The plans tell you to make the tips, then carve a slot in the inboard tip for the leadouts. I decided that since the thing is built up from all the right sizes of wood, I'd build the slot into the tip and carve around it. The middle lamination for the tip is 1/4" and I like a 1/8" slot, so I just whacked a hunk out of the middle, marked where the remaining bits landed on the two outer plates, and made a pair of 1/16" thick plywood rub plates. Then I glued the plywood bits to the wood, and then I laminated up my stack -- viola, I had a tip plate blank with a nice hard-faced leadout slot.
The final picture is the two tips (the outer is glued to the wing already, the inner has the leadout guide shoved in the slot so that I will not forget to install it before the tip goes on. Most of the tools I used are there, too -- a utility knife, two sanding boards (different grits), a home-made gouge, and a home-made whittling knife.
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Got the leadouts finished. I used 1/16" copper tubing for the ends rather than eyelets -- it makes a very clean termination, and I was able to get the leadout lengths matched to within my eyeball's ability to estimate the flap horn being flat.
The leadout guide is mounted on some scrap pieces of lite-ply, because just putting it on a rib seemed inadequate. The leadout terminations are done using 1/16" copper tubing (K&S, bought from Amazon). Using soft tubing allowed me to do a very tidy job of terminating the leadouts, and let me get them matched in length to well within my eyeball's ability to tell that the flap horn was at neutral.
The leadout assembly is done more or less to a method that Igor Burger showed on a European forum (I think it was Polish -- all I can remember for sure is that it's not Slovak, but on questioning Igor told me that if you can speak one Slavic language then you can read them all, so people just post in their native languages and everyone else reads their posts just fine).
The procedure was to mark the extreme "in" extent of the leadouts using masking tape, then to install one tube on one leadout. Having done that, getting the other tube located was just a matter of putting it on, matching it's end to the end of the already-installed leadout, then giving the thing a light crimp, just enough to hold onto the leadout until it's bent.
I used round-nose pliers to do all the bending, per Igor's tutorial. I wish that I had gotten a pair ages ago; I've wasted 40 years trying to make nice bends in wire with just about everything but round-nose pliers.
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At the Tune Up this past weekend Paul Walker mentioned that with the split flap horn, you need to nail down the flap horn travel from side to side. He'll undoubtedly have the right way to do it in his article; after coming up with several Really Complicated ways of doing this, I realized that I could just stuff some plywood and bass strips down the slots to narrow them up.
Which I did.
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I put the flaps on and noticed that the top of the left (inside) wingtip tapers down horrendously. The other tip tapers up, but less bad and on the bottom. I think this has something to do with being a right-handed wingtip carver.
It needed a lot of filling, so I chose to use wood. The method I use is to sand the patch and the piece to fit -- in this case I sanded flats into the tip -- then glue the piece on, carve & sand when the glue is hard, and repeat as necessary.
In the past I've used just about every glue for this except epoxy, and the best has been Ambroid or SigMent -- but even that has left a discernible ridge. This time around I had some Ambroid handy that's been thinned half & half with acetone. I painted it on with an acid brush (double glued -- if you just apply Ambroid and stick things together the glue soaks into the wood and leaves nothing for the joint. Doubly so for thinned. So you apply glue, let it dry, then do it again). It worked great. The pictures tell the story, except for the final carving & sanding.
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Not fixing mistakes, not TUT weirdness, but real forward progress (however small): got the landing gear leg blocks finished.
The Legacy kit puts the jig hole right through the LG block so if you're using the jig you can't put in the LG blocks when called for. So I just put them in, and will drill the holes soon. Then I'll cuss because the holes aren't quite right, but I know how to cope with that.
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LG blocks drilled, and LG legs inspected closely. Why didn't I scratch build this one? I either use these and have visions of the leg snapping right where it turns to go into the wing, or I take the time to bend up new ones.
Woe is me, etc., etc.
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LG bent (more) correctly. There are guidelines for bending structural members -- bending it over something sharp is not generally in the guidelines.
Kit LG is to the right, new LG is to the left. The only fault in the newly bent stuff is that, because of the bender I'm using, the bend kind of trails off to the bottom instead of starting and stopping promptly -- you need to think about where that's more acceptable as you bend stuff.
(The bender is basically a home-built copy of a Biso Bender arbor, without any handle-thingie: I just bend wire around it with my hands.)
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Maybe the stress man would sign off the kinked one.
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Last little bit (I think) on the wing. Weight box is done. Simple, straightforward construction is best. I wish I could manage it.
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Finally finished doing this & that to the wing and set it aside, cleaned up my bench, reached into the kit box for the engine bearers, and found -- this.
@#$%
Kits!
Fortunately I have replacement wood that is whole and straight-grained.
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Finally finished doing this & that to the wing and set it aside, cleaned up my bench, reached into the kit box for the engine bearers, and found -- this.
@#$%
Kits!
Fortunately I have replacement wood that is whole and straight-grained.
Wow, hard to beloeve that anyone would select wood like that for engine bearers!!!
It's common to find some that isn't very straight, but that has to be the worst I've seen for wood grain direction.
Randy Cuberly
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Tim,
I don't know your plans for building the Fuselage, but I would strongly reccommend building a crutch first by perparing the individual bearers with aluminum facing with the bearers relieved about 1/8 inch behind the engine (makes locating the tank easier), then drilling the engine mounting holes in the individual bearers and bolting the engine to them. This aligns each bearer to the engine mounting surfaces. Then cut 3/8 cross grain balsa and epoxy it between the bearers with everything clamped gently to a flat surface (I use glass covered with wax paper as shown in the pictures). I also strongly reccommend a Jig something like the one shown in the photo. I think Tom Morris makes something like this...but not sure about that. I used to make some like the one shown in the photo. Not hard to do but does require a good table saw to get everything square. The whole thing needs to be very stiff also. The one shown is reinforced with steel angle on the bottom (lengthwise).
The advantage to all this is that it allows the Fuse to be built pretty stress free because the engine itself determines the angular position of the mounting surfaces. No twisting or bending when the engine is tightened down. This makes for far less stress and vibration cracking in the fuselage over the years of usage.
Randy Cuberly
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Wow, hard to beloeve that anyone would select wood like that for engine bearers!!!
It's common to find some that isn't very straight, but that has to be the worst I've seen for wood grain direction.
If you look closely you'll see that the grain is fairly straight at the right of the picture, then curves. I think it was just sawn from wood that had curvy grain, and then got by QC somehow.
I don't know your plans for building the Fuselage, but I would strongly reccommend building a crutch first by perparing the individual bearers with aluminum facing with the bearers <snip>
That's more or less what I was planning on doing: getting the crutch built with the aluminum bearers, etc. My flying buddy has a jig that I'm planning on borrowing. He used assembly triangles that cost $2 each at Horror Freight, on a heavy board of some sort.
I'm planning on making the aluminum motor mounts 3/16", and bolting the motor to them, then bolting the mounts to the bearers. This isn't just to spread the force from the motor -- I'm also anticipating engine swaps, so I'm trying to make the thing so that I can easily change out an engine just by changing bearers.
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If you look closely you'll see that the grain is fairly straight at the right of the picture, then curves. I think it was just sawn from wood that had curvy grain, and then got by QC somehow.
That's more or less what I was planning on doing: getting the crutch built with the aluminum bearers, etc. My flying buddy has a jig that I'm planning on borrowing. He used assembly triangles that cost $2 each at Horror Freight, on a heavy board of some sort.
I'm planning on making the aluminum motor mounts 3/16", and bolting the motor to them, then bolting the mounts to the bearers. This isn't just to spread the force from the motor -- I'm also anticipating engine swaps, so I'm trying to make the thing so that I can easily change out an engine just by changing bearers.
I don't know what you're using for an engine but most of the PA's, ROJetts, and european engines all have the same mounting holes etc.
3/16 in aluminum is a lot of weight and unnecessary unless you plan to use tapped holes in it, in which case it's marginally not thick enough!
Randy Cuberly
Sorry about having to constantly correct typing errors...I stuck a finger in Burt Brokaws 22,000 RPM prop a few days ago and the bandage makes typing very clumsy! HB~> HB~> n~
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Looking at one of your pictures I see a "crankcase cooling vent". Crankcases typically run cooler than ambient.
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Looking at one of your pictures I see a "crankcase cooling vent". Crankcases typically run cooler than ambient.
Hi Howard,
Was that comment directed to me or to Tim. The only time I've used what could be construed as a "crankcase cooling vent" was on my GeoXL and it was actually a small vent to the venturi for the long shaft Belko that has the intake located 180 degrees from where most engines have them. In an inverted position for the engine the intake is on the top, which is a pretty static area for air flow on that particular airplane hence the "scoop style" vent for the intake.
If the comment was aimed at Tim, then...Never Mind!
Randy Cuberly
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Was that comment directed to me or to Tim.
The Legacy plans call out a crankcase cooling vent. Howard is being -- Howard.
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The Legacy plans call out a crankcase cooling vent. Howard is being -- Howard.
Huh...Howard are you wearing that Clown Suit again? LL~ LL~ LL~
Randy Cuberly
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Howard never leaves home without it.
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I got out the stuff to do the stab -- none of the sticks are less than 8lb/cu ft, and one is at least 13 (I mistook it for motor mount stock!) Moreover, they're all bent to some degree or another.
So -- off the deep end! This thing is getting a foam-cored stab. I have enough wood that's contest weight or nearly so; if I can be sparing enough with the glue I should be able to do a stab that's not too much worse than the kit one for weight, and a heck of a lot straighter.
Yesterday was spent cutting lots and lots of foam, to get a few pieces that will be good enough for cores, and even then only after I sand to size. Bob Hunt I'm not.
This may not end up being the best kit build ever, but I think it'll rank up there with the most whined about.
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I got out the stuff to do the stab -- none of the sticks are less than 8lb/cu ft, and one is at least 13 (I mistook it for motor mount stock!) Moreover, they're all bent to some degree or another.
So -- off the deep end! This thing is getting a foam-cored stab. I have enough wood that's contest weight or nearly so; if I can be sparing enough with the glue I should be able to do a stab that's not too much worse than the kit one for weight, and a heck of a lot straighter.
Yesterday was spent cutting lots and lots of foam, to get a few pieces that will be good enough for cores, and even then only after I sand to size. Bob Hunt I'm not.
This may not end up being the best kit build ever, but I think it'll rank up there with the most whined about.
Hi Tim,
This question may be a bit ot of order and you may even have answered it before but I'm curious to know what engine you are planning to use in this Legacy?
Randy Cuberly
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What, you're considering all the weight I must be adding, and thinking I'll need a small-block Chevy?
I plan on putting a Byron Barker Magnum 52 in it. I'm also planning on making the motor mounts such that I can swap in a different engine at need, since I've heard contradictory stories about the suitability of that engine for that airframe.
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Gee Tim, mine is in silkspan. You need to move it along.
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Gee Tim, mine is in silkspan. You need to move it along.
Paying work first, alas.
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I ended up not deepening any LE notches. I did two things, the first probably smarter than the second. The first side I just let the LE be straight, and then I came back later and put in shims where it didn't quite reach the notches. Three or four ribs were affected. On the second, I forced the LE a bit. This put a 1/16" deep wow in the LE, which I then went back and shimmed up with a balsa strip, sanded down flat. It'll leave some stresses (hence, not so good), but I think that once the LE sheet is on it won't mess the wing up.
To bring the ribs out to the sheeting, I'm going to shim it. I can't quite bend 1/16" balsa along the grain to match the rib, so I soaked some balsa and bent it on "Bertha", my antique soldering iron that I inherited from a radio-amateur uncle. The pictures are of the bent wood being held up against ribs to dry, and Bertha.
Balsa wood is astonishingly easy to bend if you use a bit of heat. I use the shank of Bertha (not the tip!) which is probably a bit hot. Get the wood wet -- it doesn't have to soak for long -- then tug on the ends while pulling it down over the iron. It'll buckle if you don't keep some tension on it and give it time (I think that's because the wood in contact with the iron gets hot and pliable first; keeping a pull on it makes the bend want to happen by stretching the outside fibers, and waiting gives the outside a chance to get hot). I've never tried wood thicker than 1/16", but it's great for Bostonian-sized airplanes.
Tim,
I've bent balsa up to 3/8 square by soaking it in ammonia overnight. If the wood is selected as
soft enough, you get the feeling you could tie a piece of 1/16 into a square knot and not break it.
For 1/16 LE sheeting I usually just spray it with Windex on the outside surface and wait 5 minutes.
I think Windex has ammonia in it,
Rex
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I've bent balsa up to 3/8 square by soaking it in ammonia overnight.
Been there, done that, heat works better.
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What, you're considering all the weight I must be adding, and thinking I'll need a small-block Chevy?
I plan on putting a Byron Barker Magnum 52 in it. I'm also planning on making the motor mounts such that I can swap in a different engine at need, since I've heard contradictory stories about the suitability of that engine for that airframe.
I've seen three Legacy's built from kits and flown two of them. None of them were what I would call "light weights" One was in fact 69 oz all were over 64 oz. In my opinion it's a good design and a good wing and will cary some weight if there's enough of the right kind of power.
I can't personally speak for the Barker Magnum 52 as I've never even seen one. I will say however that of the three Legacy's I've seen two were powered by ST60's and the other had a PA61 Side Exhaust. Of the ones I flew and helped trim the PA61 definitely was the best of the lot. None were "overpowered".
I'm inclined to reccommend what I know works! So I would definitely go with the PA if you can find one...there are some around!
Second choice would be a ROJett 61 either on a pipe or with the exhaust header. In fact the ROJett on a pipe is one sweet setup...ask Brett.
Randy Cuberly
Definitely do not handicap yourself with an underpowered airplane.
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Definitely do not handicap yourself with an underpowered airplane.
My Legacy weighs 62 Oz and glides quite well; really a floater. When I ran out of fuel inverted in the clover, I
managed to spin it back upright for a half-lap before level landing. I'm starting to think that the fuselage layout and
stab size (really big) were influenced by the Adams' Special.
The power plant is a Saito .56; no doubt a lot less power than the RJ .61
Rex
-
Definitely do not handicap yourself with an underpowered airplane.
That's why the motor mounts will be configured for engine swapping -- if the current engine is a mistake, I won't be stuck with it.
-
I built a kit Legacy with a T&L Super Tigre 51. This seems the ideal power. I built another Legacy "clone" from the plans with a Stalker 51, which is also the ideal power. Both weigh just about 60 oz.
Floyd
-
Tim,
I've bent balsa up to 3/8 square by soaking it in ammonia overnight. If the wood is selected as
soft enough, you get the feeling you could tie a piece of 1/16 into a square knot and not break it.
For 1/16 LE sheeting I usually just spray it with Windex on the outside surface and wait 5 minutes.
I think Windex has ammonia in it,
Rex
Ammonia permanently weakens the fibers of the wood. I would not reccommend this for any application that will be stressed such as a model wing!
Randy Cuberly
-
I built a kit Legacy with a T&L Super Tigre 51. This seems the ideal power. I built another Legacy "clone" from the plans with a Stalker 51, which is also the ideal power. Both weigh just about 60 oz.
I'm eyeing the Stalkers -- they seem like a good value/performance tradeoff for the level of tricks I can perform with these toy airplanes. If the Magnum doesn't work out and I can fit a Stalker into the budget -- it may well happen.
-
Hi Howard,
Was that comment directed to me or to Tim. The only time I've used what could be construed as a "crankcase cooling vent" was on my GeoXL and it was actually a small vent to the venturi for the long shaft Belko that has the intake located 180 degrees from where most engines have them. In an inverted position for the engine the intake is on the top, which is a pretty static area for air flow on that particular airplane hence the "scoop style" vent for the intake.
If the comment was aimed at Tim, then...Never Mind!
Randy Cuberly
Love the trim scheme on that Algorithm. Strange looking prop, what is it ?
-
I should actually watch some of Bob Hunt's videos so that I can pretend I know what I'm doing.
At any rate, I'm gluing a perimeter of balsa around the foam core of one elevator half. At the moment I'm still experimenting to make sure I'm not on some totally bogus path, hence I'm taking baby steps. From front to back in the picture are: weights that are holding the core (with trailing edge already glued on) to the leading edge, the core (and weights), the leading edge (and weights), an aluminum straight edge (and weights), and then the junk on my workbench.
I'm using Sig-Bond, which sounds like a strange choice, but I've found it to work well for gluing foam to wood, at least if you give it time to dry.
-
I should actually watch some of Bob Hunt's videos so that I can pretend I know what I'm doing.
I recommend them, at least those I've seen.
Good thing you're using gold weights. They are dense and chemically inert.
-
None were "overpowered".
Randy Cuberly
Definitely do not handicap yourself with an underpowered airplane.
That's right brother!!
One of the biggest mistakes I see with guys just starting out is, an inability to handle heavy power in a stunt ship. I can tell you from experience, the right amount of power is not enough!!
One of the biggest differences I've seen between the established Expert flyers, and the newbies is that, you will almost always see heavy power in the nose of the seasoned cats.
-
Here is what power is: https://en.wikipedia.org/wiki/Power_%28physics%29 .
-
Here is what power is: https://en.wikipedia.org/wiki/Power_%28physics%29 .
That's not in the sense of "There is no good and evil, boy, there is only Power, and the willingness to use it".
-
In 2003 I acquired a Legacy kit and planned on putting a Saito .56 in it. Later, while working on it Saito was on sale at the model expo and I bought a .72 and sold the .56 After building most of it and being dissatisfied with the progress I weighed the already completed wing. The itself was 13 oz. Calling it portly was being nice. With the rest of it that was completed, stab, elev, and most of the fuselage it was going to come in at well over 70 oz. It was all kit wood. After nearly two years of staring at it in my shop I tossed the whole mess. Hopefully the manufacturer has improved on their wood selection, though it doesn't sound like it. I sold the .72 as well without ever running either one of them.
-
Love the trim scheme on that Algorithm. Strange looking prop, what is it ?
Hi Allan,
I don't want to hijack this thread with long discussions of my Algorithm...but thanks for the comment!
The airplane is actually a slightly modified Werwage GeoXL and it's powered by a Belko long shaft .56. The prop is a Belko made especially for that engine and is carbon over foam and is very light and efficient. The Belko is a strange engine in appearance but runs just about perfect for stunt on No Nitro fuel. The airplane weighed 54 oz and is 730 Sq/In wing area. The venturi is on the bottom of the shaft and hence on top in the inverted installation which does complicate the engine installation.
If I had any sense I'd build another one of these since this one was stolen from the flying field after the idiot that owned it drove home and left it there for about 2 hours before realizing it!
Randy Cuberly
-
Here is what power is: https://en.wikipedia.org/wiki/Power_%28physics%29 .
Thanks for the reminder Howard. LL~ LL~ LL~
However power is consumed at different levels during the total time of the stunt pattern and if more is needed than available at any given time it can be disasterous...uuhhh as in a stall at the third corner of the hourglass. Don't ask me how I proved that. It wasn't just mathematically! HB~> HB~> HB~> y1 y1 That's what happens when there isn't enough available power to do the required work for a given period of time!
Hence a "pot" of more available power when required is a good idea. If not used it simply isn't in the equation...neither is disaster! LL~ LL~
Randy Cuberly
PS: Tim, apologies for drifting from the actual point of your thread!
-
I'm eyeing the Stalkers -- they seem like a good value/performance tradeoff for the level of tricks I can perform with these toy airplanes. If the Magnum doesn't work out and I can fit a Stalker into the budget -- it may well happen.
The Large Stalker engines are very good. The smaller ones are somewhat limited in available power compared to other types in equal sizes.
At least that's been my experience. The 60 size Stalker would probably be a good choice. Kaz Minato has developed a new 77 that looks very attractive and relatively light at about 12 oz. He claims it runs like a PA75. He's tested the prototype extensivly in a couple of different airplanes, Hard to do better than that if you suspect your airplane will be on the porky side.
I have one of them on order as soon as the productions ones are available and blessed by Kaz.
Randy Cuberly
-
Thanks for the reminder Howard. LL~ LL~ LL~
However power is consumed at different levels during the total time of the stunt pattern and if more is needed than available at any given time it can be disasterous...uuhhh as in a stall at the third corner of the hourglass. Don't ask me how I proved that. It wasn't just mathematically! HB~> HB~> HB~> y1 y1 That's what happens when there isn't enough available power to do the required work for a given period of time!
Hence a "pot" of more available power when required is a good idea. If not used it simply isn't in the equation...neither is disaster! LL~ LL~
Randy Cuberly
PS: Tim, apologies for drifting from the actual point of your thread!
What you're describing isn't power. Maybe it's rate of change of power with speed. Who knows?
-
What you're describing isn't power. Maybe it's rate of change of power with speed. Who knows?
Yes I agree Howard. But once again this isn't a discussion of engineering technicalties and the semantics are well understood in a non-technical way. Dont dismiss the rate of change of power with with speed and work with Who Knows!...
In a discussion of technical subjects with some non-engineering folks it's necessary to modify the semantics of technical discussion or you simply lose them and that accomplishes nothing, and turns a lot of them away. I know you want to instruct, I feel the same way sometimes...but it just doesn't work to take a critical attitude in discussions like this. Some people think engineers are just overbearing jerks anyway.
Randy Cuberly
-
Some people think engineers are just overbearing jerks anyway.
Overbearing jerks happen when you rev the engine and drop the clutch.
-
Some people think engineers are just overbearing jerks anyway.
Guilty as charged.
Why not just talk right? You aren't doing anybody a favor by intentionally using technical terms wrong. If you understand the concept, you should be able to communicate it to a nontechnical person using language correctly. No, I don't think that stunt people have a consistent, alternate definition of power. If so, where is it written and why?
-
Guilty as charged.
Why not just talk right? You aren't doing anybody a favor by intentionally using technical terms wrong. If you understand the concept, you should be able to communicate it to a nontechnical person using language correctly. No, I don't think that stunt people have a consistent, alternate definition of power. If so, where is it written and why?
They have one they generally understand...and by the way you understand it too, it's just not a technical definition. They probably don't want to be engineers!
Randy cuberly
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Why not just talk right? You aren't doing anybody a favor by intentionally using technical terms wrong.
Randy used the term "available power", not just "power". I don't think it's a bad moniker for the effect.
If you feel bound and determined to continue the argument, could you start up a thread in the Engineering forum? I think it's an interesting topic, but if you continue it here some vandal will be constantly posting pictures of a model airplane build. Like this one, of one finished elevator half core and the other one all glued up, waiting to have a good fraction of itself turned into sanding dust.
(The finished one weighs 0.22oz. I don't know if that's good or bad, but I do know that it's lighter than it's share of the two rock-hard leading edge sticks that were supplied. I need to be careful with the 20 lb/ft3 one: I've already mistaken it for a motor mount once!).
-
Tim,
This is a link to Kaz Minato's discussion about the new 77 engine...very pretty at any rate. You can bet if Kaz thinks it's worthwhile, it is!
http://kazminato.cocolog-nifty.com/blog/2014/11/new-75-engine.html
Randy Cuberly
PS: less than 1/2 oz for a stab sounds pretty good. The hardware and hinges probably weigh more than that!
-
- Weight of elevator half core with perimeter: 0.22oz
- Weight of elevator half core + skins: 0.46oz
- Weight of elevator half freshly glued with Sig Bond: 0.63oz
- Estimated weight after more thorough drying: 0.53oz
Weight loss due to drying is based on a test piece of Sig Bond that went from 0.9oz to 0.4oz as it dried while I was 180 miles south of here having fun flying toy airplanes.
The elevator halves were glued up all that time, but they were sandwiched between chunks of waxed paper, and lost less than 0.02oz each. Now they're stacked on spacers so that free air can flow over them. I'm assuming from the weight and the smell (they smell very strongly of Sig Bond) that all that the "drying" time has done has been to distribute the water from the glue throughout the wood. I'll be monitoring the things to see how they do as they dry out, and as I make the stabilizers.
-
- Weight of elevator half core with perimeter: 0.22oz
- Weight of elevator half core + skins: 0.46oz
- Weight of elevator half freshly glued with Sig Bond: 0.63oz
- Estimated weight after more thorough drying: 0.53oz
Downside to using water-based glue: it's been 8 days since I originally glued it up, four of them have been stacked with airflow and a fan, and the pieces are only down to 0.56oz. Either that last bit of water is there but coming out really slowly, or it's just not going to come out.
At any rate, I got the braces for rounding, and the LE and TE pieces glued on to the stabilizer (with less glue, too). You can see that I believe in using weights for clamping. It's mostly brass, with some scrap bits of steel and one treasured hunk of tungsten. It's too bad you can't get blocks of degenerate neutronium on Amazon.
-
Downside to taking an 8-day hiatus from building: you forget what the @#$% you were doing.
Adding bits to the cores is much easier when they're out of the assembly rather than in. It was all sanded and ready for sheeting when I realized that I didn't have anything backing it up inside where it meets the fuse. So, some careful whacking with an xacto knife, some careful wood cutting and gluing and -- now I need to wait a bit before I do the next thing.
Tomorrow it'll be ready for skins. I may even do it tonight.
-
There's a stabilizer underneath all that stuff.
The core with surround and wood weighed in at 2.02 oz; plus glue it was 2.68 oz. Given what happened with the elevators I expect that to drop to about 2.4 oz. Not wonderful, but it's not far from what I would have gotten with the kit wood, and it should be stiffer and finish out easier.
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There's a stabilizer underneath all that stuff.
The core with surround and wood weighed in at 2.02 oz; plus glue it was 2.68 oz. Given what happened with the elevators I expect that to drop to about 2.4 oz. Not wonderful, but it's not far from what I would have gotten with the kit wood, and it should be stiffer and finish out easier.
A stab that weighs 2.4 ounces sounds porky to me. Bad place for excess weight. I am on the Pacific coast camping currently, so I do not have my weights handy (they are all recorded, wink wink Howard), but I will chime in next Tuesday. My guess is that it should be more like an ounce less than what you have.
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That's about what I estimate I'd get using the kit wood.
But yes, that sounds porky to me, too. I'm flat out of 3/8" wood of any weight whatsoever, other than the rather heavy sticks that came with the kit, so I can't do much about it without ordering wood and waiting for it to show up.
Edit: It'll get lighter when I trim it and round the corners and all that stuff. But I doubt it'll drop by an ounce.
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That's about what I estimate I'd get using the kit wood.
But yes, that sounds porky to me, too. I'm flat out of 3/8" wood of any weight whatsoever, other than the rather heavy sticks that came with the kit, so I can't do much about it without ordering wood and waiting for it to show up.
Edit: It'll get lighter when I trim it and round the corners and all that stuff. But I doubt it'll drop by an ounce.
Tim,
My Trivial Pursuit Stab and Elevator assembled with Tom Morris adjustable horn, 8 hinges and ball link, weighs 2.4 oz. It is built from very light wood. It's built up structure and is 1/2 inch thick at the hinge line.
Based on this I have to agree that you stab is pretty "Porky"
Randy Cuberly
-
Here is what power is: https://en.wikipedia.org/wiki/Power_%28physics%29 .
In hopes of lightening up our pomposity I would like to share another Wiki reference to power which may take a broader point of view. Here, also, are what power are:
Power
From Wikipedia, the free encyclopedia
Look up power in Wiktionary, the free dictionary.
Power may refer to:
Contents
1 Science
1.1 Mathematics
1.2 Physics
1.3 Computing
1.4 Social sciences and politics
2 Entertainment
2.1 Film
2.2 Literature
2.3 Music
2.3.1 Albums
2.3.2 Songs
2.4 Sports
2.5 Television
3 Other
3.1 Places
4 See also
Science
Mathematics
Exponentiation
Power of a point
Statistical power
Physics
Power (physics), the rate at which work is performed or energy is converted
Electric power, the rate at which electrical energy is transferred by a circuit
Horsepower, a unit of measurement for a mechanical engine's power
In optics,
Magnification, the factor by which an optical system enlarges an image
Optical power, the degree to which a lens converges or diverges light
Computing
Various related RISC instruction set architectures
Power Architecture, a RISC microprocessor architecture
Power.org, a consortium promoting this architecture
IBM POWER Instruction Set Architecture
PowerPC
IBM Power (software), an IBM systems software operating system enhancement package
MS PowerPoint, slide-presentation software
Social sciences and politics
Economic power, purchasing, monopoly, bargaining, managerial, class, or short-side power
Hard power
Police power
Power and control in abusive relationships
Power harassment
Power (international relations)
Emerging power
Middle power
Great power
Regional power
Small power
Superpower
Power projection
Power (social and political), the ability to influence people or events
Smart power
Soft power
Entertainment
Film
Power (1986 film)
Power (2013 film), a Bollywood film
Power (2014 Telugu film), an Telugu film starring Ravi Teja and Hansika Motwani
Power (2014 Kannada film), a Kannada film starring Puneeth Rajkumar and Trisha
The Power (film), a 1968 science fiction film
Power, a 1928 comedy film starring William Boyd, Alan Hale, and Jacqueline Logan
Literature
Girl Got Game, originally Power!! a manga series
Power (Fast novel), a 1962 novel by Howard Fast
Power (play), a 2003 play by Nick Dear
Power (Stiehl novel), a novel by J. A. Stiehl
Power: A New Social Analysis, a 1938 sociology book by Bertrand Russell
The Power (novel), a 1956 book by Frank M. Robinson, on which the 1968 film is based
The Power (book), a 2010 self-help book by Rhonda Byrne
Music
Albums
Power (Barrabás album), 1973
Power (Boys Noize album)
Power (B.A.P EP), 2012
Power (Nekrogoblikon EP)
Power (Ice-T album), 1988
Power (Kansas album), 1986
Power, an album by Lakeside
Power (Q and Not U album), 2004
Power, by The Temptations, 1980
Power (Tower of Power album), 1987
Power, an album by SSD
The Power (album), by Vanessa Amorosi
Songs
"Power" (B.A.P EP), 2012
"Power", a song by Fields of the Nephilim
"Power" (Helloween song), 1996
"Power", a song by John Oswald, 1975
"Power" (Kanye West song), 2010
"Power", a song by Kat Graham (2013)
"Power" (KMFDM song), 1996
"Power", a song by Lipps Inc. from Mouth to Mouth
"Power", a song by Rainbow from Straight Between the Eyes
"Power", a song by Tears for Fears from Elemental
"Power", a song by The Temptations, title track of 1980 album
"The Power", a song by Cher from Believe
"The Power", a song by Manowar from Louder Than Hell
"The Power" (Snap! song), 1990
Sports
Phil Taylor (darts player) (born 1960), English darts champion nicknamed "The Power"
Pittsburgh Power, an Arena Football League
Port Adelaide Football Club, nicknamed "Power", an Australian rules football club
Power (horse), a British thoroughbred
Power F.C., a professional football club based in Koforidua, Ghana
West Virginia Power, a minor league baseball team
Television
Power (Starz TV series), a 2014 drama series on Starz about a New York City illegal drug network
"Power", an episode of season 6 of the drama series Smallville
Other
Power (name), a list of persons with the surname
2C-P, psychedelic popularly known as power
Power (UTA station), a light rail station in Salt Lake City, Utah
Power!, a 1985 video game
Power98FM, an English-language radio station in Singapore
Power (production company), a British television production company
Powers, a rank in the Christian angelic hierarchy
A quizbowl term meaning to get a question before a predesignated point for additional points
The Power (XM), an XM satellite radio channel
Power of appointment, a legal term, related to trust law
Power of attorney, a legal term
Places
Power, Montana, a census-designated place
Power, West Virginia, an unincorporated community
Power County, Idaho
See also
J. D. Power and Associates, a global marketing information services firm
POW-R, a set of commercial dithering and noise shaping algorithms
Powers (disambiguation)
-
In hopes of lightening up our pomposity I would like to share another Wiki reference to power which may take a broader point of view. Here, also, are what power are:
Power
From Wikipedia, the free encyclopedia
Look up power in Wiktionary, the free dictionary.
Power may refer to:
Contents
1 Science
1.1 Mathematics
1.2 Physics
1.3 Computing
1.4 Social sciences and politics
2 Entertainment
2.1 Film
2.2 Literature
2.3 Music
2.3.1 Albums
2.3.2 Songs
2.4 Sports
2.5 Television
3 Other
3.1 Places
4 See also
Science
Mathematics
Exponentiation
Power of a point
Statistical power
Physics
Power (physics), the rate at which work is performed or energy is converted
Electric power, the rate at which electrical energy is transferred by a circuit
Horsepower, a unit of measurement for a mechanical engine's power
In optics,
Magnification, the factor by which an optical system enlarges an image
Optical power, the degree to which a lens converges or diverges light
Computing
Various related RISC instruction set architectures
Power Architecture, a RISC microprocessor architecture
Power.org, a consortium promoting this architecture
IBM POWER Instruction Set Architecture
PowerPC
IBM Power (software), an IBM systems software operating system enhancement package
MS PowerPoint, slide-presentation software
Social sciences and politics
Economic power, purchasing, monopoly, bargaining, managerial, class, or short-side power
Hard power
Police power
Power and control in abusive relationships
Power harassment
Power (international relations)
Emerging power
Middle power
Great power
Regional power
Small power
Superpower
Power projection
Power (social and political), the ability to influence people or events
Smart power
Soft power
Entertainment
Film
Power (1986 film)
Power (2013 film), a Bollywood film
Power (2014 Telugu film), an Telugu film starring Ravi Teja and Hansika Motwani
Power (2014 Kannada film), a Kannada film starring Puneeth Rajkumar and Trisha
The Power (film), a 1968 science fiction film
Power, a 1928 comedy film starring William Boyd, Alan Hale, and Jacqueline Logan
Literature
Girl Got Game, originally Power!! a manga series
Power (Fast novel), a 1962 novel by Howard Fast
Power (play), a 2003 play by Nick Dear
Power (Stiehl novel), a novel by J. A. Stiehl
Power: A New Social Analysis, a 1938 sociology book by Bertrand Russell
The Power (novel), a 1956 book by Frank M. Robinson, on which the 1968 film is based
The Power (book), a 2010 self-help book by Rhonda Byrne
Music
Albums
Power (Barrabás album), 1973
Power (Boys Noize album)
Power (B.A.P EP), 2012
Power (Nekrogoblikon EP)
Power (Ice-T album), 1988
Power (Kansas album), 1986
Power, an album by Lakeside
Power (Q and Not U album), 2004
Power, by The Temptations, 1980
Power (Tower of Power album), 1987
Power, an album by SSD
The Power (album), by Vanessa Amorosi
Songs
"Power" (B.A.P EP), 2012
"Power", a song by Fields of the Nephilim
"Power" (Helloween song), 1996
"Power", a song by John Oswald, 1975
"Power" (Kanye West song), 2010
"Power", a song by Kat Graham (2013)
"Power" (KMFDM song), 1996
"Power", a song by Lipps Inc. from Mouth to Mouth
"Power", a song by Rainbow from Straight Between the Eyes
"Power", a song by Tears for Fears from Elemental
"Power", a song by The Temptations, title track of 1980 album
"The Power", a song by Cher from Believe
"The Power", a song by Manowar from Louder Than Hell
"The Power" (Snap! song), 1990
Sports
Phil Taylor (darts player) (born 1960), English darts champion nicknamed "The Power"
Pittsburgh Power, an Arena Football League
Port Adelaide Football Club, nicknamed "Power", an Australian rules football club
Power (horse), a British thoroughbred
Power F.C., a professional football club based in Koforidua, Ghana
West Virginia Power, a minor league baseball team
Television
Power (Starz TV series), a 2014 drama series on Starz about a New York City illegal drug network
"Power", an episode of season 6 of the drama series Smallville
Other
Power (name), a list of persons with the surname
2C-P, psychedelic popularly known as power
Power (UTA station), a light rail station in Salt Lake City, Utah
Power!, a 1985 video game
Power98FM, an English-language radio station in Singapore
Power (production company), a British television production company
Powers, a rank in the Christian angelic hierarchy
A quizbowl term meaning to get a question before a predesignated point for additional points
The Power (XM), an XM satellite radio channel
Power of appointment, a legal term, related to trust law
Power of attorney, a legal term
Places
Power, Montana, a census-designated place
Power, West Virginia, an unincorporated community
Power County, Idaho
See also
J. D. Power and Associates, a global marketing information services firm
POW-R, a set of commercial dithering and noise shaping algorithms
Powers (disambiguation)
Yeah, Howard, Take that!!!
LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~!!!
-
Sure, and "moment" can be a vague time interval, justifying the use of it for something physical it doesn't mean. I picked the physics definition for power out of that list because you were talking about the characteristics of an engine, for which power is uniquely defined. People's understanding of technical subjects depends on a foundation of knowledge, part of which is an agreed-upon vocabulary. No, I don't think that "power" has a unique stunt definition that all stunt fliers understand. If it did, it could be translated in a word or two to standard technical talk, and Tim could program it into his TUT. In the words of a manufacturer of name-brand stunt engines, "Those xxxxxs don't know what they want."
-
Sure, and "moment" can be a vague time interval, justifying the use of it for something physical it doesn't mean. I picked the physics definition for power out of that list because you were talking about the characteristics of an engine, for which power is uniquely defined. People's understanding of technical subjects depends on a foundation of knowledge, part of which is an agreed-upon vocabulary. No, I don't think that "power" has a unique stunt definition that all stunt fliers understand. If it did, it could be translated in a word or two to standard technical talk, and Tim could program it into his TUT. In the words of a manufacturer of name-brand stunt engines, "Those xxxxxs don't know what they want."
Well I for one do know Howard, as you do and Tim does, as does all the other engineers on the forum. I just don't believe in "tilting at windmills" Some folks do I guess!
Hey Tim,
Sorry this is stuck in your building thread. I promise not to go any further with this thing!
Did you see my post on the weight of my TP stab and elevator? I think you probably need to rebuild yours using better wood.
Randy Cuberly
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Did you see my post on the weight of my TP stab and elevator? I think you probably need to rebuild yours using better wood.
Yours and Paul's, yes.
Better wood and maybe less glue. I went for about 12 thin beads of glue per inch; I suspect I should cut that by a factor of two over the foam.
I had been about to build the fuselage, then realized I wanted the stab & elevator to do fit checks on the controls, so I built 'em. I think I'll order a bunch of wood from National Balsa now, proceed on the fuselage, and then if the stuff doesn't get magically lighter when I sand it to shape (there's lots of wood to be taken off, but not that much) I'll use it for fit checks & whatnot, but replace it with new wood for the actual flying surfaces that go into the plane.
Maybe I can use the thing for a 1/2-A wing.
-
The stab is 2.12oz after sanding, elevator half is 1/2 ounce.
Sigh. Hello, National Balsa?
-
I'm back. Checked the logs.
Predator 2014 stab weighed 33 g before paint (1.16 ounces).
It is a take apart configuration and has hardwood inserts for the attachment to the fuse.
The elevator halves weighed 9 g each before paint.
With good wood you can match those numbers.
-
and Tim,, you want to,, trust me,, ask me how I know,, sigh
-
Wood finally ordered; progress should happen soon.
I ordered 3/8" and 1/2" sheet balsa; I'm planning on rip sawing it into sticks for the surfaces (with leftovers for quick profile builds).
So, about the time that you are all enjoying the Nats, I'll be here, sweating and building.
-
Wood finally ordered; progress should happen soon.
For a certain value of "soon", apparently. I just got through a whole bunch of distractions and I'm now down to a bare building board and some wood pieces.
Having read a thread in the engineering section on stab LE shapes, I think I'll put a pointy LE on this one, per what I think Paul Walker and Brett were saying on the subject. Make it lighter, too.
-
soon is after all a non defined period of time relative to something
so I just built my third Horizantal stab for my new bird, the first two were over 2 ounces,, the new one is 1.3 ounces,, I will stay with it,,
now get to building, you need this for hte regionals,,
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Look! Real live progress! Wood clamped together and glue drying and everything!
I'm not aiming at less than 2 ounces, though -- I'm going to be happy with less than stab #1. Better heavy and done and another started than this one not done, I think.
-
woo ohooo progress,, you go Tim
-
now get to building, you need this for hte regionals,,
Probably Salem, if not next year. I'll be Atlantasing this year.
-
Stab done. It only took me three or four days, yipee.
-
Tim, what density of wood did you get to build the new stabilizer from? ???
Howard, could we just agree to the use of the term "grunt", as most motorcyclists do? y1 Steve
-
- Weight of elevator half core with perimeter: 0.22oz
- Weight of elevator half core + skins: 0.46oz
- Weight of elevator half freshly glued with Sig Bond: 0.63oz
- Estimated weight after more thorough drying: 0.53oz
Tim,
Your weight on the elevators is high. Bad place in the plane for that.
I just made two new HT assemblies and the elevators were sanded from 3/8 sheet and weigh around 10 grams each. You should be able to match that!
Throw those heavy ones away and make some light ones.
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There's a stabilizer underneath all that stuff.
The core with surround and wood weighed in at 2.02 oz; plus glue it was 2.68 oz. Given what happened with the elevators I expect that to drop to about 2.4 oz. Not wonderful, but it's not far from what I would have gotten with the kit wood, and it should be stiffer and finish out easier.
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Like my elevator post, that stab is REAL heavy. Toss it also. Both my new stabs weighed 38 grams. Way less than 2 ounces. I have no doubt you could do this as well.
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Steve: 6lb or better for everything except the ribs, which are scraps from the kit and feel like they're between 6 and 8.
Paul: Yes, I'm rebuilding the whole horizontal tail assembly. I was aiming at something between the atrociously heavy weight I ended up with and the seemingly magical weights you're getting. The stab, as framed up and with a lot of excess wood yet to be sanded off, is 1.4 ounces. I'm thinking I'll lose about 0.2 ounces in the process of whacking it down to match the plans.
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For some reason the kit calls out these huge expanses of 1/2" balsa sheet in the stab and elevators -- something like 2" wide on the ends and 4" wide in the stab center. I've cut those down considerably (3/4" wide at the tips and 1-1/2" wide in the center). Hopefully this translates into less weight. I could see maybe doing it if I had some super-contest 4 pound wood, but then, I can think of better things to do with such wood than use it there.
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On to the elevators. Just the outlines are done, but hey -- progress, right? Not shown are the internal fillets, which match those on the stab. I'm just waiting for glue to dry so I can shape the internal fillets (Sig-Bond doesn't like you putting pressure on it after a few hours, as it just reminded me).
Here's a pic of the elevator outlines, plus a bonus pic of the amount of wood that I left in the box compared to what the kit wanted me to use (the arrows point to the ends of the wood per the plan). I did the math, and it only amounts to 1/4 of an ounce or so for the stab and less for the elevators -- but lightness is lightness, and you should build in as much as you can, right?
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Tim,
I've bent balsa up to 3/8 square by soaking it in ammonia overnight. If the wood is selected as
soft enough, you get the feeling you could tie a piece of 1/16 into a square knot and not break it.
For 1/16 LE sheeting I usually just spray it with Windex on the outside surface and wait 5 minutes.
I think Windex has ammonia in it,
Rex
Boil big sticks in water using a small diameter capped pipe cut to the length you need...use a torch for heat and all you need to do is make steam. It will make any wood as limp as a noodle. A piece of 2x4 pine can be tied in a knot with this method...seen it personally. I had good success with a steam iron on my models too.
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Nuthin' but a trophy shot -- lookee, I got the elevators framed up!
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Good Trophy!
There's an amazing amount of satisfaction in building something like this, isn't there!! #^ y1
Randy Cuberly
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There's an amazing amount of satisfaction in building something like this, isn't there!! #^ y1
It keeps me going.
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Horizontal surfaces done. 2.22 oz is what I'm going to live with this time around.
Edit:
Predator 2014 stab weighed 33 g before paint (1.16 ounces).
The elevator halves weighed 9 g each before paint.
With good wood you can match those numbers.
OK, I'm not Paul -- his total is 1.8 ounces, mine is 2.2. I'm going to see if I can do better next time around, perhaps with lighter wood.
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On to the fuselage. I really like the idea of building a motor mount crutch that's all square and right and tight, and then building a fuselage around it.
So here it is, with the glue drying. I'll be finding out presently what difficulties this engenders vs. building the mounts into the fuselage.
Edit: Aaaand - I just ripped it apart and I'm re-doing it. I had the bearers parallel to one another the long way, but not the short way. I should have done a dry-fit and checked that -- I missed. Stand by...
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The problem with using your hobby shop to do fix-it jobs around the house is that the jobs GET IN THE WAY.
Crutch dry fit, everything measured. I'm about to mix glue.
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Glued. Fits better than the dry fit -- one of the rails was tilted a hair, which I solved with some shims under the clamps. It's on the opposite side, though, so no pictures.
This should be stronger than my original crutch -- I needed the formers in there to hold things square, but they should also keep the thing stronger if I decide I need to sand on it to make it perfect.
You can't see it, but I trimmed the formers by 1/8" on top, because I plan on using 1/4" thick motor mount plates. This isn't just a "make it better than Alan" things -- I'm going to use the motor mount plates as adapters, so I can easily swap other engines in there if I feel a need. I mean after all -- I really ought to see if a 25LA will work in this plane, right?
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I hate kits. The fuselage sides are bowed by a hair more than 1/16" across their length. So I need to shave the tops to make them flat, and then adjust the stab opening. Oh joy. At least there was a scrap out in the metal shop that was straight and longer than the fuse -- otherwise I'd be whining about a lack of a straight edge.
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I'm modifying things a little bit (I think that's the theme song for this whole build, actually).
I just hate the notion of whacking holes in the fuselage to put the wing in -- I keep thinking of all those nice long wood fibers that are just carelessly cut up. I especially didn't like the notion of cutting across that nice plywood doubler and leaving a huge weak spot right in between two strong spots.
So I'm pre-whacking the doubler such that when I cut the fuse open to put in the wing I'll just be cutting balsa, and in a different spot than the plywood is cut. Then, when I put the wing in, I'll put the doubler back -- and it'll be doubled by the tail end of the engine bearers. So that part of the fuselage should all be tied together much more thoroughly, without adding any more weight than was originally called out in the plans.
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I ended up stripping a bit more than 1/16 of an inch off of the fuselage sides and the doublers. Grr. So my plane will be a bit thin up and down, but at least it won't have a sway-back.
A friend of mine was downsizing and got rid of a 4-foot diameter glass table top. I scarfed it up because I was looking for a nice flat surface to build models on (there will be a build thread on the table for that, I think). Along with that came some panes of glass that are 12" x 16" x 3/8" -- that's what I'm using to keep my fuselage sides flat while the doublers go on.
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Today's progress: a bit of trimming on my newly-doubled fuselage halves, and a table.
I scored a 4 foot round, 5/8" thick glass table top a while back from a friend (the same one that the plates came from). Today I went to the local Habitat for Humanity thrift store and picked up a battered corner cabinet for $40. The super-complex build procedure for the table was to set the top on the cabinet. It's nice and solid, and holds up an Atlantis quite well.
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I am glad to see you gaining momentum again Tim..
I have finally started making myself work on something, no matter how small , every night,, one night I cut out the tips and roughed them, next night carved and hollowed one tip and got it on, next night did second one, then weight box,, on small thing... its coming together, as is yours,,
Are you planning on Portland?
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Forgot to post the picture. Scruffy, but with a very high utility to cost ratio.
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now you need a spotlight,, and a turntable under the glass ( with underchassis illumination) and you could have your own air glamour show in the garage,,
are you going to make Portland? cant wait to see you fly the Atlantis,,
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now you need a spotlight,, and a turntable under the glass ( with underchassis illumination) and you could have your own air glamour show in the garage,,
are you going to make Portland? cant wait to see you fly the Atlantis,,
I've always felt that sticking mirrors under show cars was about as classy as sticking a mirror under your date's dress.
I'm certainly planning on going to the Tune Up. If the rains abate enough for me to practice I may even fly decently.
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Fuse front glued up, and all the vertical formers in. It's either made or ruined now.
The first picture is about how I got the glue on without making a mess -- I marked out where the "glue to" areas were, and only put epoxy on those areas. It seemed to go well.
No fuse jig, but the thing is checked every which way with triangles to make sure it's OK.
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Well, it's ever so slightly diamond shaped as viewed from the front, so if I see a judge heading toward it with a carpenter's square I'll know I'm doomed. But I'll be able to get engine, wings and tail all in a straight line, so I think I'll keep it.
The kit gave me this lovely big hunk of 3/4" balsa for a top deck -- I'm spurning Brodak's generosity and I'm going to make a molded top deck like Bob Hunt does. Or at least I'm going to try...
Bob uses blue foam. No one has it locally, and I like the way that polyurethane foam sands. So that's what I'm using. Michaels has it in the floral arrangement section of the store, six blocks for $5. I used one block for the mold, so I'm doing pretty good.
I'm not going to go into much detail on this because Bob has a really nice write-up out there on how to do it, and I'm in doubt about whether my deviations from Bob's Way are improvements or just stupid. What you see here are, in order: the fuse top shape traced onto a hunk of lite-ply, with three blocks of foam cut from one of the store-bought blocks; the foam glued onto the lite-ply, with balsa formers tack-glued in place -- I'll use these formers in the top deck; and finally, gluing a hefty 1x2 spine onto the lite-ply outline (which I should have done first). After the glue dries I'll start sanding, and hopefully everything will work.
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I am going through that same learning curve myself Tim, I used sheeting on top and bottom on the Green Impact, but a different aproach. The blue foam is of course insulation foam, Home depot, or Lowes or pretty much any building supply company of worth will have it. THe thing I didnt like about the floral foam is that its fairly fragile and can compress easily ( at least the floral foam I have is) but the blue foam seems to be problematic in that its rather plastic, malleable , and doesnt cut well with sandpaper,, though I did just get a couple sheets of long board 36 grit and I will find out if that works better to rough it out,
anyway, not trying to hijack yoru thread, just sharing..
good luck,, and pick the right grain balsa for molding, learned that one the hard way too.. sigh
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I am going through that same learning curve myself Tim, I used sheeting on top and bottom on the Green Impact, but a different aproach. The blue foam is of course insulation foam, Home depot, or Lowes or pretty much any building supply company of worth will have it. THe thing I didnt like about the floral foam is that its fairly fragile and can compress easily ( at least the floral foam I have is) but the blue foam seems to be problematic in that its rather plastic, malleable , and doesnt cut well with sandpaper,, though I did just get a couple sheets of long board 36 grit and I will find out if that works better to rough it out,
anyway, not trying to hijack yoru thread, just sharing..
good luck,, and pick the right grain balsa for molding, learned that one the hard way too.. sigh
Our local Home Depot only has the white stuff, at least as far as I've been able to find. I've got some 3" wide sheets that are A-grain along most of the width and C-grain on the last half inch or so, and I need to splice two together anyway -- so it'll be A grain all the way across when I'm done.
And yes, I'll find out soon if the floral foam is a mistake. For $10 it won't be an expensive one.
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Hey Tim,
Thanks for the heads up when I judge that plane in the future. I'll look close!! ;D
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Hey Tim,
Thanks for the heads up when I judge that plane in the future. I'll look close!! ;D
A padded carpenter's square, please -- don't scratch the paint. It's only off by half a degree or so -- I'm not sure you could eyeball it.
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A padded carpenter's square, please -- don't scratch the paint. It's only off by half a degree or so -- I'm not sure you could eyeball it.
Hey Tim,, he wont need to, you already told him,, no square needed,, see this is why I dont say negative stuff about mine,, all the people who judge are on here LOL
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Actual progress. I had been stuck, agonizing over whether I wanted to carve out the top block in the front or do another molding. Carving would be easier and somewhat heavier, molding looked like it'd be much harder to get right than the back. Carving finally won, and I can make forward progress again. Obviously the carving and hollowing has yet to be done.
The plans call out carving the block, then hollowing while leaving cross-pieces in. I suspect I'm going to hollow the whole thing, then add cross-pieces (of cross-grain wood) after the fact -- y'all can laugh at me later if it turns out to be a stupid idea.
The plans show a crankcase cooling vent on top of the plane, which, after much thinking (and asking questions) I decided to retain. Thread here: http://stunthanger.com/smf/engine-set-up-tips/crankcase-cooling/ (http://stunthanger.com/smf/engine-set-up-tips/crankcase-cooling/). The holes are drilled and the drill marks sanded out. They don't show well because of the lighting: they're the light-colored "nostrils" up front there.
The plans show the two top blocks butted against each other. I don't like the idea of all that lovely end-to-end strength rudely interrupted in the middle: dire thoughts of a fatigue crack right there kept bothering me. I'm splicing them. It's just a lap splice, but it's still a splice and should add more strength than weight.
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I should be doing my taxes, not playing with airplanes.
I roughed out the front top block and got it tacked down to the nose. The crankcase vents are more apparent here, as is the roughness of the roughing out. The dark spot at the back of the front top block is there because I made the rear deck a bit taller than the block supplied by Brodak, so I had to add a bit to the front top block to match. Eventually a cockpit will be whacked out of all of this, but I want to get it shaped nice first.
Not entirely obvious, but you can see the edge of a clamp reaching through the wing opening -- I make a lot of little custom one-use clamps out of balsa sticks and rubber bands. There never seems to be just the right clamp, unless you make what you need.
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Yes it is amazing what we do with scrap balsa, rubber bands, tape and clothes pins.
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Here, Richard. I am too getting work done.
The look of those crankcase vents is inspiring me. I'm going to paint the plane green on the top; I think a light dusting of white powder around the nostrils should be suggestive, don't you think?
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Could someone please review for me why this is fun?
Broken tap. Grr. It was feeling a little stiff, and I allowed my attention to wander about 1/4 of a turn further than I should have. Hopefully I can extract it without having to learn whether the alum trick works.
Edit: And no spare taps. Oh joy.
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Hey Tim, can I use that credit card to order some new wood please?
lol
Hey I know the fun, did you have any tapping oil? it makes a HUGE difference in aluminum,,
on a side note, preparing my next column, how about some pictures of the progress ;D
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Hey Tim, can I use that credit card to order some new wood please?
If I haven't mixed epoxy with it yet, sure.
Hey I know the fun, did you have any tapping oil? it makes a HUGE difference in aluminum,,
on a side note, preparing my next column, how about some pictures of the progress ;D
Sharp taps make a bigger difference -- that one is from a tool box I inherited from my uncle in 1988. I finished the hole with a new bottoming tap and it cut as slick as could be. I just can't tap a straight hole with a bottoming tap.
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Engine fits. I keep straying from the sequence in the instruction book, because I get worried if something will work and I hare off and get 'er done. But -- the engine fits, and I can easily put something different in if necessary.
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Report?
Did that OS motor work out for the Legacy?
How was the balance??
Thanks,
Chris
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Gee, Tim. Are you working on the Legacy again?
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Gee, Tim. Are you working on the Legacy again?
Nope. I'm flying the Atlantis, keeping Robin in functioning airplanes (she crashed one this morning), working a full time job, and supporting my two remaining customers.
Oh, and trying to get the latest version of the TUT writing files to disk, so that Howard can record flight data before we all die of old age.
Report?
Did that OS motor work out for the Legacy?
How was the balance??
See my response to Randy -- basically, I'm stalled on the Legacy build, pending other things. However, now that I'm working a full time job again I'm actually getting in more shop time. Things were getting pretty grim with my business toward the end, and it was sapping my attention.
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Nope. I'm flying the Atlantis, keeping Robin in functioning airplanes (she crashed one this morning), working a full time job, and supporting my two remaining customers.
Oh, and trying to get the latest version of the TUT writing files to disk, so that Howard can record flight data before we all die of old age.
See my response to Randy -- basically, I'm stalled on the Legacy build, pending other things. However, now that I'm working a full time job again I'm actually getting in more shop time. Things were getting pretty grim with my business toward the end, and it was sapping my attention.
Yeah, Being in business for yourself is a "Bitch". Everybody wants everything for free or cheap and there's nobody else to blame for anything! No place to hide either! LL~ LL~ LL~ I've done it also and believe me when I say...NO MORE! It's Heart Attack City! Made a few good friends and a few enemies and decided it's just not worth it! Still owed a LOT of money that I'll probably never collect! HB~> More fun just building model airplanes! y1 y1
Randy Cuberly
Randy Cuberly
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Ok, Tim. Glad it's on the hit list for you now.
I was curious if you'll stick with the OS .55 it looks like you have in the nose, and if it'll be light enough not to throw off your balance. Not to mention how they run for stunt.
I'm looking for something of a similar power, that's why.
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Ok, Tim. Glad it's on the hit list for you now.
I was curious if you'll stick with the OS .55 it looks like you have in the nose, and if it'll be light enough not to throw off your balance. Not to mention how they run for stunt.
I'm looking for something of a similar power, that's why.
It's a 46AX-II, and I'm giving it a whirl because the 46LA is no longer in production. I may end up having no end of trouble with it -- that's part of the reason why I built the thing with aluminum bearers for the motor: I can swap in just about anything with a smaller crank case than the AX, and just about anything you might want shoved in there is that size or smaller.
I'm currently flying Paul Walker's 1988 Atlantis, with a 46LA in it, and at 64 ounces and 700 square inches it flies great. If you're not going to get a purpose-built stunt engine I think the sensible thing to do is to use a bone-stock 46LA. (Sensible-er would be a piped PA, if you can get one. I may or may not be that sensible: I'm definitely not flush enough to buy the setup).
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It's a 46AX-II, and I'm giving it a whirl because the 46LA is no longer in production. I may end up having no end of trouble with it -- that's part of the reason why I built the thing with aluminum bearers for the motor: I can swap in just about anything with a smaller crank case than the AX, and just about anything you might want shoved in there is that size or smaller.
I'm currently flying Paul Walker's 1988 Atlantis, with a 46LA in it, and at 64 ounces and 700 square inches it flies great. If you're not going to get a purpose-built stunt engine I think the sensible thing to do is to use a bone-stock 46LA. (Sensible-er would be a piped PA, if you can get one. I may or may not be that sensible: I'm definitely not flush enough to buy the setup).
Tim,
Both the 55AX and the 46AXII will run great in a Stunter. The venturi size is a little more critical on the 46 but mine works well with a .275 size with a Aero Needle assembly. The 45 is very strong and will fly just about anything you want to put it in. A 12.5-4 APC or 12-4.25 bolly or Mejelic 3 blade also works great.
The 55AX is a power house (albeit a bit heavy at 12.25 oz with a tongue muffler) that will turn 13-4 APC or even 13-4 three blades with ease. I ran a 55AX in a ARF SV22 for a while and it was a great combination. I finally gave it to Chip Hyde several years ago when he crashed his ratty old Nobler and he flew it for quite a while until he bought a Crossfire from Hunt. I got the engine back from him after that and still have it. It still works very well. I used a .284 venturi with an Aero needle assembly and two layers of panty hose on the venturi. I would guess that about a .280 venturi or a bit smaller would be perfect also without the panty hose material. The 55AX is a very flexible engine set up that way and would definitely fly any stunter anyone would want to build. It's also a very tractable engine that shows absosutely no tendency to run away or speed up in maneuvers. Closest thing to a pipe set up of any engines I have used. Used a tongue muffler from RSM designed for the OS46AF series with every other hole in the muffler enlarged to .156.
It used 5.5 oz of 15% nitro fuel for the pattern both here and in CA.
I don't understand why more people haven't discovered this engine given the expense and shortage of anything else that runs as well.
Randy Cuberly
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Thanks for the details, Randy.
What does the .46AX weight (if you remember) and would you pick the 46 or the 55 for a 650" plane? From what I can tell on the OS website, the .46 is one ounce lighter without muffler than the .55 without the muffler. Wonder what the difference in the carb weights are, but in theory, if the .55 is 12.8oz with a nylon venturi, then maybe the .46 is 11.8 or so?
I would like to know if you have the info though.
Thanks.
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FYI-
The OS.46AXll weights 11.5 oz with no muffler, carb or remote needle valve. I just weighed mine.
I hope the tongue muffler and venturi and needle weigh about 1oz, probably they will weigh a bit more, I would guess.
So maybe 13oz RTF I would guess.
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Yea, yea, yea.
Cleaned up my bench today so I could work on the Ercoupe (https://stunthanger.com/smf/scale-models/ercoupe-build-(slow)/msg545144/#msg545144). I made enough room that while I'm waiting for glue to dry on the one, I can work on the other!
Like a hostage holding a newspaper, I include proof that this is actually today, and not a pic from long ago (although, the Ercoupe fuselage in the background is proof, too).
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Top block's been waiting for a very long time for me to do something to it. Here's the weight before I started hollowing, the hollowed block, and hollowed + former. Rather than trying to hollow out multiple wells the way everyone seems to want me to do, I decided to hollow it all out and fit a former to it. Hopefully it won't turn out to be a dumb idea.
It's hollowed exactly to the depth of my courage, and no farther. You can see light through it all across the well, including one spot in front where you can see a scary amount of light. I may rub some Ambroid on that spot.
The former is glued in with Gorilla Glue, because the fit's not all that good.
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Tim,
I built the Allen Brickhaus Legacy from a Brodak kit. It went together pretty well. About the only modification I made was to make it a take apart model. As the Legacy is a rather large airplane, I thought making it come apart for transport would make it easier. Of course, there are no instructions, or accommodations to adapt the airplane for that modification. I think I did rather well.
Good luck with yours!
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Another picture that I couldn't get to stick to my last post.
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What the heck- one more...
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Nice. I'd be a little leary on using a clevis for the elevator pushrod.
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I've done that on a few blocks. To me it is lighter even though it takes some time to fit the formers. D>K
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I've done that on a few blocks. To me it is lighter even though it takes some time to fit the formers. D>K
I think I spent less time fitting the former than I would have trying to make two wells instead of one.
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Tim,
Nice job on the top block! That weight seems respectable.
I just redid a Legacy ARF top. The sheeted portion was all wavy and had some crunching. And the removable front cover seemed like a really bad idea. Replaced it with a block, only lightly hollowed (no guts, but no cracks either), tried to fill the wavy, and one layer of very thin glass. Your construction seems to solve all those issues.
Nice!
Dave
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Itty bitty modicum of work done, while waiting for some dope to dry on the Ercoupe, and standing by to give advice to my wife, who's doing her first kit built plane (an Akromaster).
Part of fiddling around and not getting work done on this involved switching over to electric -- so I'm converting this one over as I go. I'm having good success with a BadAss 2826 in the similar-sized Atlantis, so I'm probably going to go with that for this plane. It looks like if I can get enough air flowing through the motor I'll be A-OK.
Picture shows a rear mount mostly marked up. That's 1/8" phenolic.
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Itty bitty modicum of work done, while waiting for some dope to dry on the Ercoupe, and standing by to give advice to my wife, who's doing her first kit built plane (an Akromaster).
Part of fiddling around and not getting work done on this involved switching over to electric -- so I'm converting this one over as I go. I'm having good success with a BadAss 2826 in the similar-sized Atlantis, so I'm probably going to go with that for this plane. It looks like if I can get enough air flowing through the motor I'll be A-OK.
Picture shows a rear mount mostly marked up. That's 1/8" phenolic.
That's a great motor. I have one and several of the Cobra versions. Fits really well in that 25 - 35 conversion zone.
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That's a great motor. I have one and several of the Cobra versions. Fits really well in that 25 - 35 conversion zone.
This is more a 40-60 conversion zone. 690 square inches, 64 ounces if I'm lucky, but I tend to build heavy so I won't fall out of my chair if it's as high as 72. I'm not committed yet -- I may go with a 35xx.
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This is more a 40-60 conversion zone. 690 square inches, 64 ounces if I'm lucky, but I tend to build heavy so I won't fall out of my chair if it's as high as 72. I'm not committed yet -- I may go with a 35xx.
The 2826 is a good 40 size equivalent I missed the 26 part. The 2820 is more suited for the 25-35 planes. The 36xx are good torque mongers and for the airplane I would probably just drop the 3520 in. It's likely the CG is going to be aft and the slightly greater weight of the 3520 will be helpful. I'd honestly go with the Badass motors in that case.
Chili, beer and spumante has me up cause I didn't take the omeprazole before going to bed. Now I'm paying for it.
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Because what's the point if it doesn't have parts that are hand machined from solid billet?
Tail wheel. The tire is from a toy semi truck from Goodwill ($1 for 10 tires!). Wheel made by taking a hunk of aluminum and cutting away all the bits that don't look like a wheel. I'll be soldering the tubing to the tail wheel strut, and using the cotter pin to retain the wheel.
I feel this gives a cleaner look than the usual wheel collar, and is more secure than soldering a washer on the end of a piece of music wire.
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Hi Tim,
Way to go buddy, stay at it until you have a straight wing. Your hard work will pay off with a good flying model, good for you. This would be a good home for the Bad Ass 3515 710 KV motor that we talked about on another post. Build the fuse to allow changing the battery pack from the left side kinda like an SV-11 with a removable battery floor to access the ESC & timer for adjustments.
Looking forward to see your progress you make on it,
Later,
Mikey
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... Build the fuse to allow changing the battery pack from the left side kinda like an SV-11 with a removable battery floor to access the ESC & timer for adjustments.
You're making me think -- really. I'm probably still going to go with a bottom hatch because, if nothing else, the fuse is already built for slime and I'm doing a last-minute conversion, and a bottom hatch means just building the cowl different, not whacking a great big hole in the fuselage.
But it's a great big hole in the _unfinished_ fuselage, so dammit, now I have to mull this over.
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Motor mount. 1/8" thick phenolic, for a rear-mounted 2826. I know the 3515 is probably better, and if I'd been building the fuselage for it from the start it wouldn't be a problem -- but I don't want to do the hacking and whacking necessary, and based on my experience with my Atlantic electric conversion, this should work.
In spite of what it looks like, that firewall/motor mount is in there straight. It's as close to vertical as I can get it, and angled toward the outside by less than a degree -- and I can always shim the motor if necessary.
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I went to test-fit everything, knowing that the motor body goes through the hole in the spinner ring [just fine], and was dismayed to find out that the motor wires wouldn't fit.
Fortunately, wiggle room was available -- I used a trick I learned from the folks who made cables at FLIR systems. You can make a fairly tight permanent bend in a wire by heating it up good and warm then bending it and holding it until it's cool. As long as you don't do that more than once or twice, you won't hurt the wires, either.
So -- motor wires bent, and the motor fits. I included a motor with un-bent wires for comparison.
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You're making me think -- really. I'm probably still going to go with a bottom hatch because, if nothing else, the fuse is already built for slime and I'm doing a last-minute conversion, and a bottom hatch means just building the cowl different, not whacking a great big hole in the fuselage.
But it's a great big hole in the _unfinished_ fuselage, so dammit, now I have to mull this over.
Side load is the way.. Never have to worry about the battery departing in normal operations.
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Side load is the way.. Never have to worry about the battery departing in normal operations.
But -- appearance points at local contests, where the judges don't always look at the bottom of the plane...
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But -- appearance points at local contests, where the judges don't always look at the bottom of the plane...
So, make it functional and cool.
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Hi Guy’s,
The side access “in my opinion” is the best way to go. You can dress it up with a cheek cowl or scoop, and, you can change batteries while it’s setting on it’s wheels for quick turnaround for the next flight.
Later,
Mikey
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Hi Guy’s,
The side access “in my opinion” is the best way to go. You can dress it up with a cheek cowl or scoop, and, you can change batteries while it’s setting on it’s wheels for quick turnaround for the next flight.
Later,
Mikey
Y'know, I still haven't figured out the best bottom-mount hatch for this thing, and your suggestion is suddenly sounding a lot better. Even if I get dinged for appearance points I think I'll do it. Given that the fuse is already half built, it'll be a way to cut out a big chunk of unnecessary plywood, too.
It'll also simplify my current problem, which is coming up with a front airscoop that's shaped nice, has the right internal ducting, and can be sanded inside and out, all while still allowing me to get the motor in and out.
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Y'know, I still haven't figured out the best bottom-mount hatch for this thing, and your suggestion is suddenly sounding a lot better. Even if I get dinged for appearance points I think I'll do it. Given that the fuse is already half built, it'll be a way to cut out a big chunk of unnecessary plywood, too.
It'll also simplify my current problem, which is coming up with a front airscoop that's shaped nice, has the right internal ducting, and can be sanded inside and out, all while still allowing me to get the motor in and out.
Side load is the way....
Lots of good reasons including being able to install the motor providing it is front mounted. Bottom mounting is a PITA since you have to turn the airplane over every time you change batteries. Get your airplane holder, get your tools, flip the airplane over, remove the hatch, unhook retention, remove battery, install new battery, replace retention device, replace hatch, flip airplane over, clear airplane holder from area. Versus, remove hatch, pull out battery, install fresh battery, replace hatch. Easy peasy v PITA. Side load is the way..
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Side load is the way....
Lots of good reasons including being able to install the motor providing it is front mounted. Bottom mounting is a PITA since you have to turn the airplane over every time you change batteries. Get your airplane holder, get your tools, flip the airplane over, remove the hatch, unhook retention, remove battery, install new battery, replace retention device, replace hatch, flip airplane over, clear airplane holder from area. Versus, remove hatch, pull out battery, install fresh battery, replace hatch. Easy peasy v PITA. Side load is the way..
The entire top third of the Expert contingent in the Pacific Northwest show up with their planes and their plane holders, and load the batteries in the pits. It's just the done thing.
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Side hatch it is! Given the amount of room that I have to cut it open, it's kind of tight. I'm going to open it up 1/4" more lengthwise and maybe 3/8" top to bottom.
Fit checks have the engineers happy and the technicians complaining about the engineers. I can get my fat fingers in there to reach behind the motor and install it, barely (good, but I think I'll be getting some long-reach, ball-end hex keys), I can get the battery in and out (good), I think I'll need to put some tabs onto the battery so I can get it out easily (well, OK), and I'm not sure yet where the timer and ESC will go -- I may put them on the hatch itself; time will tell on that one.
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A piece of tape wrapped around the battery with ends sticking out will do the trick on removal. D>K
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A piece of tape wrapped around the battery with ends sticking out will do the trick on removal. D>K
That's what I did!
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I'm not sure yet where the timer and ESC will go -- I may put them on the hatch itself; time will tell on that one.
Tim,
There may be room below the battery for the ESC and timer. A 1/16 inch ply floor with large openings glued just below the battery hatch gives a place for the battery to sit and the ESC and timer should be able to slide in from the front under the floor. Attached is a photo of a motor crutch assembly (available thru Oakieair) which should make what I'm trying to say a bit more clear. Good luck.
Don
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Tim,
Make the battery floor removable so the ESC & timer can be mounted to the bottom of the floor, they can both be removed at the same time with the battery out of the way. One of my models has the ESC and timer mounted to the inside of the hatch, works ok but the next one will have a removable battery floor for easy access to them. It’s looking pretty good so far, keep it going.
Later,
Mikey
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As I remember, the Brodak Legacy kit was easy enough to build. It is also a good starting place for experimentation and/or kit-bashing! Changing some shapes or internal construction details is part of the fun in this hobby.
I started with a Brodak kit and modified rudder and some external shapes. I got a fine flyer out of it. Mine uses a Tom Lay Super Tigre 51.
It was different enough to warrant a new name, "Larceny:
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Tim,
Make the battery floor removable so the ESC & timer can be mounted to the bottom of the floor, they can both be removed at the same time with the battery out of the way. One of my models has the ESC and timer mounted to the inside of the hatch, works ok but the next one will have a removable battery floor for easy access to them. It’s looking pretty good so far, keep it going.
Later,
Mikey
That's a good idea, and may happen now. I have an added wrinkle that -- if I ever get the software done -- there's an unreleased version of the TUT that records flight data onto a micro SD card. I want that card to be easily accessible. But I think I've figured that part out, and a removable floor in the battery space doesn't get in the way of that.
I'm certainly getting an appreciation for why the top dogs in electric are going to larger fuselages -- you can shoe-horn everything in to a slimer, but more volume would make that job much, much easier.
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After a couple of false starts I think I know how to get my brain wrapped around this whole cowl-building process. I want a big airscoop in front, similar to what I did on the Atlantis, only (hopefully) big enough to actually cool the motor down. I'm going to do it with molded balsa, so I just made a plug.
I found some appallingly heavy balsa for the job (that's the density, in oz/cubic foot) -- not only appallingly heavy, but it's like oak on one side and "normally heavy" balsa on the other. It's definitely not something you'd want to build into a plane -- too heavy to be balsa, not strong enough for motor mounts...
Of course, I measured it, noticed it was narrow, started happily whacking away at it and then realized that I needed to make it wider. If I'd paid attention I could have just glued a nice flat piece of 3/16" or 1/4" thick scrap to it. But no, I had to make it necessary to glue on a bazzilion little thinner scraps to get the thickness up. Fortunately this isn't going to actually fly with the plane. And I did manage a plug in the end.
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Making up the 6" wide sheet for the scoop. The last few times I've joined balsa together like this I've been unhappy, and I decided to always go a bit big, then sand things down.
I remembered! I used 1/8", and I'll be sanding it down to 3/32"! And dang me if the joint doesn't look just perfect! The one time I remember to adjust for an imperfect joint...
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Making up the 6" wide sheet for the scoop. The last few times I've joined balsa together like this I've been unhappy, and I decided to always go a bit big, then sand things down.
I remembered! I used 1/8", and I'll be sanding it down to 3/32"! And dang me if the joint doesn't look just perfect! The one time I remember to adjust for an imperfect joint...
What am I looking at for a weight there? Looks like a piston rod pin to me. Which happen to be some of my favorite tools around the shop. Good weights and perfect for using as rollers for the heavy machinery. I have a bunch of them from overhauling Lycomings.
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What am I looking at for a weight there? Looks like a piston rod pin to me. Which happen to be some of my favorite tools around the shop. Good weights and perfect for using as rollers for the heavy machinery. I have a bunch of them from overhauling Lycomings.
It's a cut-off of some high-alloy steel that I got at the local scrap yard. It's not quite stainless, but definitely not just iron and carbon. Way hard to machine, but using the very curvature of space-time itself, it does a great job as a clamp.
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As I remember, the Brodak Legacy kit was easy enough to build. It is also a good starting place for experimentation and/or kit-bashing! Changing some shapes or internal construction details is part of the fun in this hobby.
I started with a Brodak kit and modified rudder and some external shapes. I got a fine flyer out of it. Mine uses a Tom Lay Super Tigre 51.
It was different enough to warrant a new name, "Larceny:
I did some bashing on a Legacy kit. Converted to electric with a top load battery box and fuselage gear plus the turtle deck and fin/rudder change.
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So, not bad. I didn't want to slit the balsa where it curved in toward the front; that, plus making it around the small-radius curves at the back of the form meant wrapping it pretty tightly. That, in turn, means that I now have a nice weave pattern from the Ace bandage printed onto the wood.
Not sure what I'll do about that -- "use filler" comes to mind, but I'm concerned about it slowly flatting out under the filler over time, leaving a print in the paint.
At any rate -- I was clever twice, and that was bad. Clever once in gluing up the wood nice and fast with CA, then clever again experimenting with heating the wood for bending by boiling it. Boiling water releases CA glue -- did you know that?
My wife was helping me wrap the thing; she suggested just wrapping the two pieces -- that worked out as well as anything. I'll need to do some trimming and joining on the bottom side, but it'll work out well. Overall, I'm pleased, and my Legacy will have a nice jet-style airscoop, which is an aesthetic that I like. (To the extent that -- if you can't figure out how it should look, make it look like a jet!)
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So, not bad. I didn't want to slit the balsa where it curved in toward the front; that, plus making it around the small-radius curves at the back of the form meant wrapping it pretty tightly. That, in turn, means that I now have a nice weave pattern from the Ace bandage printed onto the wood.
Not sure what I'll do about that -- "use filler" comes to mind, but I'm concerned about it slowly flatting out under the filler over time, leaving a print in the paint.
At any rate -- I was clever twice, and that was bad. Clever once in gluing up the wood nice and fast with CA, then clever again experimenting with heating the wood for bending by boiling it. Boiling water releases CA glue -- did you know that?
My wife was helping me wrap the thing; she suggested just wrapping the two pieces -- that worked out as well as anything. I'll need to do some trimming and joining on the bottom side, but it'll work out well. Overall, I'm pleased, and my Legacy will have a nice jet-style airscoop, which is an aesthetic that I like. (To the extent that -- if you can't figure out how it should look, make it look like a jet!)
Probably a little ambitious with the tension. Practice. Looks good though.
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Probably a little ambitious with the tension. Practice. Looks good though.
Not my first rodeo (but not my 100th, either). I was putting just as much tension as I needed on that to get it to fit down to the form. Where I was too ambitious was the amount of curvature I was asking from the wood. I'm actually not unhappy with the results -- if some patterning on the wood is the cost of getting that scoop formed in one step, then I'm a happy camper.
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I put a 1/32 plywood ring on the front, for strength. Then I put a 3/32" thick balsa layer on top of that, so that the front of the scoop could be rounded.
While I was at it, I sanded the inside of the scoop, in anticipation of wanting it to be all pretty when it's on the plane.
Should be pretty when it's all covered.
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Fitted up to plane. I just decided to toss my first attempt at making the part that goes between the fuselage and the scoop -- I tried to start with a part that fit the fuse and scoop out a part to hold the scoop, all while getting everything to fit. Didn't work.
Gonna make try 2 tomorrow, with more bits & pieces in hopes that I'll have something that'll glue up into something that'll fit.
The ultimate plan (assuming I don't drive myself insane trying to make everything fit) is to finish the inside of the scoop nicely back about 1/8 or 1/4", then paint the rest of it flat black to hide all my sins.
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Fitted up to plane. I just decided to toss my first attempt at making the part that goes between the fuselage and the scoop -- I tried to start with a part that fit the fuse and scoop out a part to hold the scoop, all while getting everything to fit. Didn't work.
Gonna make try 2 tomorrow, with more bits & pieces in hopes that I'll have something that'll glue up into something that'll fit.
The ultimate plan (assuming I don't drive myself insane trying to make everything fit) is to finish the inside of the scoop nicely back about 1/8 or 1/4", then paint the rest of it flat black to hide all my sins.
It is the journey, not the destination. You start with an idea and start gluing bits of scrap together till you don't have any more holes then you carve and sand till you get it close enough for filler to hide all those joints and when it is all finished you cover it with some glass and no one ever knows that you had no idea what it was going to look like when you started and as you look at it finished, it was worth it.
I am curious what the exit hole will look like for that massive scoop!
I am one step further down that insanity trail. It's Filler Time!
Ken
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I am curious what the exit hole will look like for that massive scoop!
I think I'm glad you reminded me of that? Sigh, 'nuther chore -- at least I can think ahead, though. Probably an exit hole over the motor on the top of the cowl (which worked in the Atlantis), and louvers on the bottom of the hatch or even under the wing.
The ginormous scoop is responding to these mini-scoops on the Atlantis (https://stunthanger.com/smf/gettin-all-amp'ed-up!/electrocuting-the-atlantis/msg618110/#msg618110), which I needed to add to keep the motor temperature down. I decided that rather than trying baby steps, I'd just say "screw it, I'm doubling the area of the scoop".
The Atlantis only has exit holes that are about 2x the size of the entrance; I'll probably stick with that.
This is what I don't want:
(https://stunthanger.com/smf/index.php?action=dlattach;topic=54194.0;attach=325346;image)
(https://stunthanger.com/smf/index.php?action=dlattach;topic=54194.0;attach=325348;image)
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I will pass these along just for grins. I don't think the Legacy is classic legal, don't know about N-70 so butchering the profile some shouldn't cost you. My Endgame design is based on Tom Niehbur's "Top Hat" design. I acquired one of Tom's wings from his estate and designed the rest of the plane around it. One of the things that comes up from converting later designs is what do you do with the pipe tunnel. My ansewer was to leave it there and cover it. Some carefully placed baffles around the wing joint and you have a monstrous cavity to fill with electronic goodies and a flow through of fresh cool chopped up air!
First pix is Endgame II where I extended the hatch to give me bellcrank access. My point is how easy it was to add that aft air exit. It too will have the slots, 4 of them. Second pix is Endgame I. It had a scoop nearly as large as yours.
Ken
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Tim,
It is apparent you are a good engineer, but didn't take a single art class. I have the same problem.
Engineer says: form follows function
Artist says: function follows form
I struggle to find that balance.
It is a curse....
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Tim,
It is apparent you are a good engineer, but didn't take a single art class. I have the same problem.
Engineer says: form follows function
Artist says: function follows form
I struggle to find that balance.
It is a curse....
Well I've taken a single art class.
Anything that works is de facto prettier than anything that wins aesthetics awards but doesn't work.
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I figured the way to make it all fit is to build a cradle for the scoop out of multiple pieces, then glue it together.
The fit is still -- atrocious. To deal with that, I'll glue it together with Gorilla Foaming Glue. That's all I can think of that will sand anything close to balsa. I expect that there'll still be some filler around the scoop to cradle joint.
Once the pieces are together, making it fit the fuselage should be a matter of trimming and sanding everything flat with an idiot board.
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If your Ace bandage makes ripples in the Object d' Art, once it's stabilized, apply a bit of water to swell the wood back up to OEM condition. It'll remove much of the ripples, if not all. S?P Steve
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If your Ace bandage makes ripples in the Object d' Art, once it's stabilized, apply a bit of water to swell the wood back up to OEM condition. It'll remove much of the ripples, if not all. S?P Steve
I did, and it did.
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Started shaping the sides of the cowl and then noticed that the scoop was offset from the spinner. Decided "aw heck, I'll just make up a story about how control line planes are inherently asymmetrical".
Looked at it again this morning & decided that no, I wanted to fix it. So I sanded a bit of a wedge into the front where it butts up against the spinner ring. That moved the front over, but it also meant that I was out of wood on one side (wood that I carved off a day or two ago :o).
So -- sand in a flat spot, grab some scrap wood & some Ambroid, and make a patch. It should make a nice ridge in the covering when I'm trying to make it all flat and shiny.
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I should post a picture of the scoop as it is now. For the moment, just take my word that it's actually on the pretty side, and it should work pretty well, too, which means it'll meet my minimal definition of "pretty".
For the moment, I leave you with this. Filling a toilet paper tube with polyurethane foam makes sense given what I'm doing and what's in my shop. Really, honest, it does! And having my tape and salsa container contraption fail when it did in the curing cycle is actually better than if it overflowed on my tube. So, a small success.
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Scoop as it is now. Sanding will happen on the fuse just behind it, to fair it in.
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There's that toilet paper tube again. Gonna put some balsa on to soak. Just -- because.
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I've been trying to get a scale plane painted before the Regionals this coming Memorial day. But that's all masked up and I'm waiting for no rain.
In the mean time, slight progress has been made. It's baffling, but there's a reason I did it.
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The inside of the air scoop will be visible from the ground. So it's going to get at least a lick and a promise at finishing (and I wanted to get some paper on there, for strength).
Paper is the wrapping that DigiKey uses when they pack electronics components. It looks & acts like Esaki tissue (except for the printing). I used it in a bunch of spots on the Ercoupe project for patching mistakes. It seems to be working -- so we'll see.
When I'm done, I'll paint it flat black so that any remaining ugly doesn't show.
Also seen, I'm making a start on the electronics tray. This will go in the base of the battery compartment, leaving me (I hope!) lots of room to move the battery around for balance.
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Electronics tray getting glued in. Hopefully I can screw the stuff onto it when it's in there firmly. I'll find out!
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You have less than two weeks until the Stuntathon.
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You have less than two weeks until the Stuntathon.
I'd have to hurry, and use Monocoat.
I'll practice flying the FrankenFlyer, instead.
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Like my elevator post, that stab is REAL heavy. Toss it also. Both my new stabs weighed 38 grams. Way less than 2 ounces. I have no doubt you could do this as well.
Second try -- after forgetting Paul's advise above. Basically I sanded down the kit stab and sheeted it.
On the Very Marginally Plus side, I figured out how to do this without adding too much weight -- mostly by dint of leaving balsa out. I think I just had to fail before I could succeed here.
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I doubt that I removed more than 1/4 ounce of material (those are 1/4" diameter holes, through the 1/2" thickness of the motor mounts). And nothing will show once the airplane is buttoned up.
But damn it looks nice right now! And maybe someone will peer into my plane when I'm loading in batteries and be so unnerved by all the holes that they'll fly less good, letting me place better!
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Aside from that -- I hadn't realized just how far along I was, because I'm used to profiles, and RC planes. I'm going to get the wing covered & with a few coats of dope on it, then start doing fuselage assembly.
So -- paint, sand, paint, sand. It'll be boring as @$%^, until I get the wings in and start making the fuselage the correct shape.
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So -- paint, sand, paint, sand. It'll be boring as @$%^, until I get the wings in and start making the fuselage the correct shape.
Nice fuselage. I love the holes.
I don't bother with the beams anymore. I use an Okie printed mount screwed to the plywood doublers. That is it. And then it sits waiting for a wing. I don't think I fully realized how much you can really do on a fuselage while you wait for the wing. So I got bored and add the Canard. Better get the wing soon! I have already added full bottom hatches past the wing, a top air scope, an adjustable logarythmic flap horn with independently adjustable flaps. an adjustable mounting pad for the timer accelerometer and a cam rudder mechanism. This plane is either going to be unstoppable or the biggest waste of time since the T-Square I built as a kid. (should I admit to having built a T-Square?)
Ken
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I don't bother with the beams anymore.
When I started this build it was going to get a 46LA or a 51AX. Then I was too lazy to rip the beams out.
Much lightness could have been included if I had started with electric propulsion in mind.
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Progress is happening in bits and spurts. I'm prepping all the little bits for covering (I'm going to cover the wings & stab, get a few coats of dope on, then assemble to the fuse. May not be the smartest way, but it's how I'm going to do it).
In the mean time, this is progress. Really. Honest. It'll show from the outside; I'm anticipating that it'll polish up real pretty.
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Small-in-size, large-in-work. I didn't want to lose appearance points on some hokey-looking hatch latch. This is big (3/4" in diameter), but it's going to be shiny.
The inner part is a handle that rotates, it'll get a boring old tongue on the inside that'll catch the lip of the hatch opening. It all bolts together with lots of scary-to-machine blind 2-56 holes. Unfortunately, the ones holding it on are only 3 threads deep, which is bad, but there's three of them which is laughably over strength.
Huh -- I just thought of it as I wrote. I can cut off some screws and glue them in as studs, instead. Three threads should be sufficient until they wear out -- and glued-in studs won't wear the threads. So...
Hand machined from solid billet, just the way the cool kids built their street rods 30 years ago -- it should take a shine, and be convenient, too.
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It worked out to three screws in an irregular pattern, so the latch could actually turn. If there's a next time, it'll be a nicer pattern -- but this works. I'll buff the @#$% out of it when the plane is finished, to draw the judges attention away from the giant hatch cover it's latching.
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Battery holddown. Wrong size -- fortunately the 3D model was parameterized nicely.
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Version 1 (with the balsa spreader) and version 2 battery hold downs, pretending to hold down the battery. They don't provide enough clearance for foam or velcro to _really_ hold the battery in place -- so version 3 has been sent to my helpful coworker who can run the 3D printer, and with luck there won't be a version 4.
If I can get the wiring finalized and have everything still fit, then it'll be ready for final assembly and I can start finishing.
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With the batteries done, I'm getting the inside of the airscoop "finished". Now that it's black, I'll spray it with a coat of flattener and call it good. It's not perfect, but hopefully it'll be dark enough in there that no one will be distracted from the pristine beauty that will be the outside of the aircraft (really! That's how it's gonna be!) Once it's flat black, or as flat a black as a lick and a promise will get it, I can glue that baffle into the scoop and start fuselage assembly.
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Small-in-size, large-in-work. I didn't want to lose appearance points on some hokey-looking hatch latch. This is big (3/4" in diameter), but it's going to be shiny
I certainly hope it will be shiny. I would hate to see someone report this thread to the moderator just because its not shiny!
n1 LL~ Just kidding Tim.
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Tim, I really like your hatch latch. I am using one with a bar you pull back. Looks hokey but it works. Yours looks better and is probably lighter. Still looking for some "pig lipstick" that doesn't smell bad to make mine all shiny. LL~
Ken
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Kevin: Yes, it'll be polished and waxed. It's not so much made to disassemble easily as it happens to disassemble easily, so it should be easy to polish with power tools once a year or whatever.
Ken: That was my second attempt. I wanted something that looked like you might see it on a full-scale airplane. I really wanted do do a miniature version of a flush mount paddle latch like these (https://www.mcmaster.com/flush-mount-latches/) -- I figured that one about 1/2" high would look about right and be grabbable with a fingernail. But it has all sorts of little fiddly bits that are just fine when the thing is four inches tall, but way too little to hand-make when the thing is half an inch tall.
It's quite oversized for the "scale" of the airplane, but it should be durable, and it'll shine up.
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Nice fuselage. I love the holes.
I don't bother with the beams anymore. I use an Okie printed mount screwed to the plywood doublers. That is it. And then it sits waiting for a wing. I don't think I fully realized how much you can really do on a fuselage while you wait for the wing. So I got bored and add the Canard. Better get the wing soon! I have already added full bottom hatches past the wing, a top air scope, an adjustable logarythmic flap horn with independently adjustable flaps. an adjustable mounting pad for the timer accelerometer and a cam rudder mechanism. This plane is either going to be unstoppable or the biggest waste of time since the T-Square I built as a kid. (should I admit to having built a T-Square?)
Ken
That's impressive..!
I'd be tempted to contact cement the plastic to the wood....but I suppose that would make last minute adjustment and alignment impossible.
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It worked out to three screws in an irregular pattern, so the latch could actually turn. If there's a next time, it'll be a nicer pattern -- but this works. I'll buff the @#$% out of it when the plane is finished, to draw the judges attention away from the giant hatch cover it's latching.
Very crafty latch Tim...!
Is your other hobby gunsmithing...?
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Very crafty latch Tim...!
Is your other hobby gunsmithing...?
"How do I make a curved hole in a block of metal?"
"Give it to an apprentice and tell them to drill a straight hole!"
Nope, not good enough for gunsmithing (at least, if I tried I'd be purveying special rifle barrels where the bullet comes out the side). But I do enjoy making bits and bobs on the lathe, and I'm gradually getting better at it. By the time I'm too old to fly, I may have even made an engine that gets broken in before it's worn out.
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"How do I make a curved hole in a block of metal?"
"Give it to an apprentice and tell them to drill a straight hole!"
Nope, not good enough for gunsmithing (at least, if I tried I'd be purveying special rifle barrels where the bullet comes out the side). But I do enjoy making bits and bobs on the lathe, and I'm gradually getting better at it. By the time I'm too old to fly, I may have even made an engine that gets broken in before it's worn out.
Tim..I've considered donating time at an armory as a Janitor / Observer just to get some exposure to that level of work.....but then I'll drink a beer, then take a nap until those thoughts have drifted away by a safe distance . H^^
So far I've used my $999 Harbor Freight Lathe to shave some material off the inside of a couple Cox .049 piston skirts, made a few venturis...made an iron piston for a ST .15.
Couldn't live without it...!!
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Starting to cover. My plan is to get the wing ready to squirt with silver, then mount it into the unfinished fuselage (the kit directions have you assembling the thing before you hook up the controls and complete the fuselage).
Which leads to my first experience with carbon fiber veil.
I'm still searching for one word to describe the experience -- sub-traumatic is best, I think. I kept expecting the whole experience to explode into one of those nightmare covering jobs where you end up with looking at a disaster job that needs to be let dry and sanded off, with bits of tissue or whatever stuck to every bit of your body like some sort of a model aviation tarring and feathering. I think it may have been full-on traumatic if it weren't for all the stick-and-tissue planes I've made over the years, and various experiences with silkspan and fiberglass to augment that.
But -- it actually came out OK-ish. The worst part was discovering that I had about half as much carbon veil as I thought, which means that I need to order some more if I want to stick with my original plan and use it on the flaps -- and to have some for the fuselage. There's one corner of the thing where I left too much veil and it wouldn't lie down -- I'll have to sand that off (and pray it does so nicely) and cover those corners with silkspan.
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That CFV looks impressive..!
The edges all look real nicely rolled...
but
after reading you comment about a problem in one of the corners it makes me wonder if vacuum bagging has been tried with tissue and dope..?
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after reading you comment about a problem in one of the corners it makes me wonder if vacuum bagging has been tried with tissue and dope..?
First, the problems with the corners would be there under a vacuum bag, too -- I was just asking the veil to go around more of a compound curvature than it can go.
Second, dope dries so quickly I don't think you'd have time to get it into the bag before it dried out -- which would defeat the whole purpose.
Third, I'm sure this is a solved problem somewhere, but vacuum bagging anything that depends on evaporation is going to be -- interesting. Because you need to make sure that evaporation will happen, which means that at minimum you need a path from every bit of the thing you're molding to the outlet for your evaporate (i.e., the solvent from your dope, glue or whatever, or water from a molded balsa piece) to escape. You probably also need to either have dry air flow, or you need to bring the temperature up so that the vapor pressure of your evaporate is high enough to drive it out of your material.
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Just a trophy shot of the wing all covered, with various amounts of dope on each bit. All the flying surfaces except the fin (which doesn't exist yet) are covered and getting dope build-up.
Open bays are covered with polyspan, tips with Doctor Paper (which is turning out well), leading edge with CF (which, uh -- read on).
I think Doctor Paper actually worked better than "real" silkspan for the tips -- it has a bit less wet strength than silkspan, which lets you tug it around compound corners to a greater degree than you could do with silkspan.
Using carbon veil on the leading edges instead of doing the whole wing in polyspan definitely has a historically high ratio of "sounded good" to "turned out well". It's just -- wrinkly. And the wrinkles aren't rubbing down. I know there's a bit of compound curvature in those leading edges, and apparently it's too much for the covering. I tried to alleviate that by covering the second one (the near one in the photo) in sections -- that just made the problem worse. Lengthwise strips may have worked, but it's too late now!
So I'll be sanding the wrinkles off. If things look good enough they'll get doped. If the result is scabrous enough I'll probably sand the whole LE and apply polyspan or doctor paper. Then I'll publish my shame here so that you can avoid my mistakes, and instead go off and make new, original mistakes of your own!
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Yup. Scabrous. Dangit.
Time to tack one more error onto the concatenation of errors...
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Where did you get your CF veil?
What did you use to attach the CF Veil??
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CST Sales, it's their 0.2oz/square yard stuff (which seems to handle a lot like the Deluxe Materials 0.3oz/square yard stuff, for a lot less $$). I'm applying it with dope.
I'm not familiar with CF much. If it were fiberglass (of which I have extensive, if decades-old, experience) I'd say it had some sizing in it that's not soluble in dope -- it sure seems to stay stiff even when it's wet. But -- maybe that's just how CF acts?
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CST Sales, it's their 0.2oz/square yard stuff (which seems to handle a lot like the Deluxe Materials 0.3oz/square yard stuff, for a lot less $$). I'm applying it with dope.
I'm not familiar with CF much. If it were fiberglass (of which I have extensive, if decades-old, experience) I'd say it had some sizing in it that's not soluble in dope -- it sure seems to stay stiff even when it's wet. But -- maybe that's just how CF acts?
Sorry to hear about your struggles with the CFV Tim.
I have only read about it in the past as the latest and greatest thing but have never tried it.
Those wing tips did turn out great and now I need to find me some of that Doctor Paper..!
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Those wing tips did turn out great and now I need to find me some of that Doctor Paper..!
If you don't have it already just use Silkspan. Or if you fly rubber power and have some of that cheap "domestic" tissue around use that. It's not worth getting a roll of it just for the odd super-compound curvature bit.
From Paul's comments I may be misusing the CF veil (and it does work great on utterly flat surfaces).
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If you don't have it already just use Silkspan. Or if you fly rubber power and have some of that cheap "domestic" tissue around use that. It's not worth getting a roll of it just for the odd super-compound curvature bit.
From Paul's comments I may be misusing the CF veil (and it does work great on utterly flat surfaces).
Tim.....If you think the material has "sizing" [or a contamination] that prevents thorough saturation then you could try tacking it to an open frame and washing it with some dope thinner from your spray gun...?
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Tim.....If you think the material has "sizing" [or a contamination] that prevents thorough saturation then you could try tacking it to an open frame and washing it with some dope thinner from your spray gun...?
I was careful in my wording -- it acts like it has a sizing in it. That doesn't mean it necessarily does. If I found out for sure one way or another, I would not be surprised -- one way or another.
And if it does have sizing, it's not soluable in thinned dope, so spraying it with straight thinner won't make a difference.
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Dude, did you start building this plane in 2015?
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Tim,
I use only ACP carbon matt. I learned this the hard way, just like you have. I cut to shape, lay it down and brush on clear dope thined 50%. It goes through the veil and the sizing nearly instantly, and once through it can go over most any compound curve.
I love it so much I only use it, no tissue here.
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Dude, did you start building this plane in 2015?
Well, yes. My life has been eventful in a non-modelling way in the interim. And it does put a double meaning into the word "Legacy".
Tim,
I use only ACP carbon matt. I learned this the hard way, just like you have...
That's actually good to hear -- especially because what I have is still useful for certain limited things (like dead flat surfaces). As long as I build enough profiles, I'll use it up. And goodness knows, I'm a prolific builder!!
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So, after some conversation with folks at the Spring Tune Up, I figured out that random CF veil has sizing that is soluble in epoxy (not surprising) and water (mildly surprising, and very welcome).
So I tried my CST Sales stuff again, treating it like silkspan. It loosens up just fine and goes on like, well, wet silkspan. Which is good, because APC Composites doesn't mess around with quantities fit for modelers any more, and I absolutely don't mind using damp CF veil.
Here's a pic. The lighting is Modeling Noir*. At any rate -- there's no wrinkles. Had I gotten this the first time around I'd have been ecstatic.
* Or I didn't want to mess around arranging stuff for a really good picture and just used my flash.
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Wow. It's amazing how changing jobs to one where you think that management actually values you can stimulate work on models.
Progress lately has mostly been paint, sand, paint, sand, so not much to take pretty pictures of.
However, I've really been unhappy with my hatch arrangement -- I kept envisioning trying to stand the airplane on my toe while juggling a battery over the hatch. I recently saw this picture of Dennis Nunes's new Circulas, and decided some surgery was in order.
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Gluing the oh-so-carefully constructed hatch into it's oh-so-carefully constructed hole (sob!)
Hopefully I've locked in the clamping action of my weights.
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So -- work wasted, weight added, the nose will, forever, have a ghost hatch showing. Oh well -- I'm going to make forward progress, dammit!
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So -- work wasted, weight added, the nose will, forever, have a ghost hatch showing. Oh well -- I'm going to make forward progress, dammit!
Not bad, not bad at all...
A little superfil after covering with silkspan, and that hatch will completely disappear. At that point, it'll only exist n the pictures shown.
Steve
Sent from my SM-N986U using Tapatalk
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Not bad, not bad at all...
A little superfil after covering with silkspan, and that hatch will completely disappear. At that point, it'll only exist n the pictures shown.
Steve
Sent from my SM-N986U using Tapatalk
I don't have enough experience with wood, but if it were a fiberglass car body it'd only be perfect at the same temperature as when it was finished out. I'll be sure to check it out the first time I take it out of my cold cold shop and get it to a sunny contest.
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Not bad, not bad at all...
A little superfil after covering with silkspan, and that hatch will completely disappear. At that point, it'll only exist n the pictures shown.
Steve
Sent from my SM-N986U using Tapatalk
And if it is still there - panel lines!
Ken
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That doesn't look bad at all, I think you're going to be surprised how well it turns out once covered. y1
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Your build is making Howard look speedy.......
Yes, superfill in the joint of bare wood and block sand when cured.
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On my 2020 Endgame that I lost in the fire, I had cut "Nobler" like lightening holes in the back. Eight of them. I was convinced by some well wishing flying buddies that the loss of strength was not worth it and I should put them back in. So I did. This left me with 32 cracks to fill. I CA'd all 8 cutouts back then block sanded till it was smooth but with cracks. SuperFil is not the easiest to use in cracks. It doesn't want to stick to both sides. However, I found that it I added a drop or 2 of denatured alcohol it went on pretty much like finishing resin. I also found that if I heated it some it would stick to both sides of the crack and penetrate the grain of the wood giving me a glass smooth surface to block sand. Since then I have added just a drop of alcohol when I mix a batch. It makes it sticky and easier to spread. Then, when it is about half cured, maybe an hour, I go over places like fillets and shape them.
The only person that will know that a hatch was there will be you....and all of us, but we won't tell!
Ken
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Your build is making Howard look speedy.......
I have to do something positive for the community.
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On my 2020 Endgame that I lost in the fire, I had cut "Nobler" like lightening holes in the back. Eight of them. I was convinced by some well wishing flying buddies that the loss of strength was not worth it and I should put them back in. So I did. This left me with 32 cracks to fill. I CA'd all 8 cutouts back then block sanded till it was smooth but with cracks. SuperFil is not the easiest to use in cracks. It doesn't want to stick to both sides. However, I found that it I added a drop or 2 of denatured alcohol it went on pretty much like finishing resin. I also found that if I heated it some it would stick to both sides of the crack and penetrate the grain of the wood giving me a glass smooth surface to block sand. Since then I have added just a drop of alcohol when I mix a batch. It makes it sticky and easier to spread. Then, when it is about half cured, maybe an hour, I go over places like fillets and shape them.
The only person that will know that a hatch was there will be you....and all of us, but we won't tell!
Ken
Once I asked Paul about his ImpAct plans, as I was confused by all the phantom lines on the fuselage drawing. He said that it showed optional cutouts (like some plans of the Nobler), but that they were not a good idea to actually do.
And, there were other phantom lines that showed the horizontal, cross-grain sheet balsa pieces on top and bottom, which make a total of THREE box/tube sections (counting boxing in the top and bottom molded sheet "blocks") and stiffen the aft fuselage. At least one company kitting the ImpAct didn't catch that, and their kit prototype omitted these pieces. Per the deal, Paul got their first kit and had them correct their oversight. H^^ Steve
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Paint, sand, paint, sand, lay down some trial panel lines where they won't show, paint, sand.
I think I like the old-timey pens that come in those drafting sets back in the days of Cerebrial Aided Design. Because you can adjust them, and they're way controllable, and if you build on my schedule they don't get clogged with ink after sitting in a drawer for a year.
And besides -- I'm using my Dad's old drafting set, probably from when he went to college on the GI bill right after getting out of the Navy some time between WW2 and Korea. Granted -- he hated college and he dropped out, but it's still his old drafting set, in a case that my grandfather Wescott probably made, so how can I say no?
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Shazbat
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I've given up on the finish. Lipstick is heavy, and this thing is just going to be a pig anyway.
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Oh, right - hardware.
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And I thought stressmen were conservatine. You take it to another level.
;D
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Horn done. It doesn't fit in the fuselage -- oh my.