stunthanger.com
Building Tips and technical articles. => Paint and finishing => Topic started by: John Miller on June 07, 2011, 06:50:02 PM
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Finishing the 2 Bits Bipe begins with a trim layout done in the CAD program. I may change the stab-elevator as It seems a bit busy, The sort of Olive drap areas is where transparent Green will be going. To conserve on weight, I plan to use Monokote or rather plastic film for the flying surfaces, and paint the fuse.
I may be trying out different trims, as the mood strikes me.
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Looks cool John, and like a LOT of work.
(Remember now, you have two wings to do) ;D :##
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Yes, too busy for me. But I like the colors.
Seems like most of the time less is better.
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After sleeping on it last night, I decided that the stab-elevator was too much, so I simplified that area, and changed to color positions on the wheel pants.
The colors still feel good, so no changes there, at least for now.
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Slight changes, I added the black anti glare panel on top of the nose, and rearranged the pants colors again.
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Better. I am not sure I am quite comfortable with the balance between wing and stab. Too different?
Maybe put a green horizontal stripe on the fin? Or make its leading edge or tip black?
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Other than using green (I'm an infamous anti-green advocate) it looks good to me. Should show up well with transparent covering.
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Boy those colors really pop! Too simple layout, send it to Randy Powell and let him do it for you. LL~ LL~ LL~ Anyway it should be easy to see. H^^
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After settling on a trim scheme and colors, I picked up several rolls of Plastic coverings in the colors I intend to use. Most of it is Monokote, and 1 roll is Ultrakote. The black is an old roll of Black Baron. I'm using it because it's a small area that will be covered with it. It's a low heat material, and I have to be careful that I don't melt it.
I plotted up the full sized patterns for the trim, and cut them up so I could cut the covering to proper shapes. It takes a bit of patience to cut the plastic covering to shape. If I wasn't so lazy, I'd make the patterns out of something heavier than paper to make it easier to follow.
The most important item of prep work for a good looking finish using 'kote finishes, is to properly sand the surface until you have a smooth surface. at least 320 grit, and a good rub down with a tack rag. sanding dust shows up like boulders under 'kote finishes.
I use a 1/8" overlap between the colors and use a trim seal iron and a piece of glass to attache the colors into one large sheet. It makes getting the trim scheme into place, much easier, and accurate.
I have the first panel on the bottom of the lower outboard wing basically finished.
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Further finishing on the bottom wing. It took 18 hours of work to get the bottom wing finished. Still have the flaps to do. At this rate, I could have painted the plane in less time. The reality is, that I didn't use a 'kote finish for the speed of it, rather for the weight savings. As it turns out, the bottom wing gained 1 ounce in the covering. If this keeps up on the top wing, and the tail feathers, I can expect to be under 3 ounces for the flying surfaces. I want to be less than 8 ounces total finish weight.
I took some pictures showing me using the patterns I made for cutting out the shapes. I really should have used 3M and stuck them to some poster board for durability. I've mangled the originals so bad cutting the shapes for the bottom wing, that I may have to print out another wing set for the top wing.
I hope you enjoy the pictures.
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Now that is impressive! Thanks for this project. Its always fun to be invited into someones shop to watch a build. H^^
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Looking great, but too much work for this old man. H^^
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Very cool John. It wont be long now......... ;D
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Yes, it's moving along pretty good. I really hope the control system shows up soon. I need to install it, close the fuse up, then I can start prepping the fuse for finish.
For the most part, and less the flaps, the wings are finished except for a few minor details yet to attend to. I mounted it all together so I could see what it looked like with color on the wings. I also installed the ply/carbon fiber hybrid gear, so it's sitting more as it should be.
I hope you enjoy the pictures. H^^
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Lookin' good John! This one should be a trip to fly. y1
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Looking good John!
Now take one of those wings and design a 15-20 sized killerstunter around it!
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Quote from Denny Adimisin "Now take one of those wings and design a 15-20 sized killer stunter around it!"
Hey John, not a bad idea after you finish the bipe - you already have the tail feathers built, right? You can use the first horizontal set you did.
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Hmmm, Hi aspect ratio, Maybe I could finish it with orange 'Kote? Of course I could get me a crate to tote it around in. S?P y1 Seriously, it wouldn't be a bad idea. 18% airfoil, 344 sq's, and as Will has pointed out, I already have the tailfeathers built.
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Hmmm, Hi aspect ratio, Maybe I could finish it with orange 'Kote? Of course I could get me a crate to tote it around in. S?P y1 Seriously, it wouldn't be a bad idea. 18% airfoil, 344 sq's, and as Will has pointed out, I already have the tailfeathers built.
Got any more green pop bottles? ;D
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Yeah, green ones are easy to get. It's the blue, red, and yellow ones that are hard to get. LL~ LL~
Man, whoever started the rumor that covering with 'kote is fast and easy lied to us. I suppose that if you did a mono chromatic finish, and didn't try hard to keep things smooth and neat looking it would be fast, but, try to do a good clean job, (Very difficult) and it takes as much, or perhaps more time than painting it in the first place. At this point in time, I've almost 40 hours invested, and still have to cover the flaps and rudder. Then I haven't even started the fuselage prep work for paint.
I did take some pictures, I hope you like them.
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Looking great. Cannot wait to see what it looks like when the fuselage is done.
Knowing my skills and patience ... I'd settle for something more simple H^^
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John,
Looks really good. I've never been able to do that piece together the covering then attach it method. Seems no matter how I work it, the pieces come apart before I can get it attached and shrunk. Oh well, I'm better at painting anyway.
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Randy, you take a back seat to few when it comes to painting a finish.
Doing this kind of "kote finish is a bit tedious, and requires patience. The panels when stuck together can, and will come apart if you're not careful, sometimes even if you are, it'll still happen. The trick I used with this particular trim scheme was having structure under most of the seams. That allows me to stick the seams down to something stable, before doing the final shrinkage.
It's tons easier to use silkspan of Koverall first, then stick the 'Kote to it. Much more stable as well. but I really wanted the transparency to show well, so no under coating was possible.
I had to rip off all of a days work on the stab, because I had no structure to stick to. I modified the method, and was able to make it work, but it wasn't the same kind of stuck together panel, though it looks like it is.
Despite my best efforts, there are areas that I'm not happy with, but I'll live with it. I realize now, why so few try for this complex of a scheme with iron ons.
I'm covering the flaps, all 4 of them, and the stab and rudder, which should be about all the 'kote that will be used on this model. After today, I should just need to build and finish the wheel pants, install the control system if it ever gets here, so I can close up the fuselage, and start the paint finish work on the fuse.
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John,
The complexity of your covering scheme is incredible....you have done an amazing job. You must have the patience of a saint !!! The first thing
that blew me away, was the layout of the "pattern" templates. I can't imagine anyone cutting out all of those patterns in Monokote.
The color layouts in the CAD drawings were impressive, but when it came alive, with the transparent green, I couldn't believe how terrific it looked.
You are definitely " 'da man".
Keep the posts coming....your work is always interesting, and inspiring.
Cheers.
Warren Wagner
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Thank you all, for your helpful comments. You help me stay focused on the job at hand, as well as good critiques. For all intents and purposes, the "Kote finish is on. There're a few places, such as the roots of the lower flaps, and trim areas inside the hinge line to touch up, but as you see it now, is pretty much the way it's going to be.
It was "interesting" going to this trim extreems with plastic film covering. I wound up throwing that partial roll of Balck Baron Film out. The heat I was using on the other films would melt the low temp BB covering, which resulted in what looked like black Bacon, all wrinkled, and curley. All but the white was MonoKote, the white was UltraKote.
I found that the MonoKote worked about the same as it always has for me, with the possible exception of the solid green, which seemed to take a little more work, and didn't seem to shrink as much as the other colors. The UltraKote was very good, and though I only had one color to judge it by, that one color worked very well.
I've never been a fan of low temp coverings, having used them in the past, I find them tto go on well, cover compound curves easier, but they seemed to loosen up faster and easier in the sun, and within a relativly short time, I've had them delaminate. The top clear plastic would start to peel away, leaving the color adhesive stil stuck to the plane. A messy situation. So hence my usual adherance to high temp coverings.
For those who may be interested, I've invested 43 hours into the 'kote finish on this plane. That doesn't count the almost 1 days work I removed because it didn't come out like I expected. The finish I wound up with, has it's flaws, and if you look close, you'll find them, but over all, I'm happy with the results.
Now, it's back to building. I'll soon have the wheel pants finished, the controls installed, and then be ready to start finishing the fuse. I'll be using paint for the fuse.
Here's a picture as it sits today.
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John,
That is one slick bipe. I hope it flies for you as well as it looks. I'm just curious, since you have four flaps rather than two, will you cut down on the travel compared to the elevator?
Bill Ambrose
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Bill, thanks for your comments and encouragement. In answer to your question, I've designed almost everything to be adjustable, removable, and replaceable, in anticipation of solving or experiencing many of the problems previously experienced by those who've tried to make a truley competitive stunt biplane. You'll notice that each flaps chord is rather narrow, the design idea was to wind up with 4 flaps that equal, or come close to the area of 2 on a mono plane. H^^
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You'll notice that each flaps chord is rather narrow, the design idea was to wind up with 4 flaps that equal, or come close to the area of 2 on a mono plane. H^^
Just a thought, and to me this is way overthinking things, but has anyone ever wondered about a wider chord flap possibly providing more leverage to the wing than a narrow chord flap?
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Several designs are out there using quite wide flaps. The Flapper by Larry Scarinzi comes to mind. I haven't read the artical, so I don't know much about the findings, or usfulness, of the concept. I do know that except for these few design excursions, such configuration did not catch on, and the designer never built a follow on design using the feature.
Contol loads may wind up becoming a problem. Overcoming the "swoopy" turns with enough elevator authority may become another.
Testing having been done by a chap "down under", where he built a unique, adjustable bellcrank, that alllowed him to vary the amount of throw on the control surfaces easily. He evenually wound up with only 7 degrees of flap to perform to his liking. It tends to make me believe that a small amount of flap, at the extreems of the B.C. rotation is more useful than more.
H^^
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I built a large bipe for stunt using a Fox 59 in the early 70's. For whatever reason, and it certainly wasn't design genius, I went with flaps on the bottom wing only. I also went with one inch chord on the flaps. The plane flew a very nice pattern except for some tail wagging in the corners, which I did not know then how to correct. It wasn't bad enough to hinder a really fun flying airplane. Looking back, I feel it could have been competitive for intermediate and advanced.
I sent the information to Al Rabe at the time, and he did an article in the June, 1973 issue of American Aircraft Modeler, page 38, titled "Bipes for stunt."
All compared my "59er" with Jack Sheeks' Stagger Wing Beechcraft and Jean Pallet's Grumman Ag-Cat. His article might be of interest to you for now as far as flaps, etc. go. The smaller flaps certainly enhance the ability to go with smaller tail surfaces, but is it worth it? With your removable and therefore changeable parts, I think you're on the path to development that will settle the bipe question once and for all. I am really pumped about your ship!
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My one foray into bi-planes was a bit different. A sorta profile canard pusher with a sort of X-wing layout. The thing flew like crap, but it was sure a blast.
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Maybe when John gets this one flying good he'll design an X wing for us? Ever since I saw Star Wars.......
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Will,
yea, that's where the idea came from. The thing actually flew OK, but just wouldn't turn all that well (a canard - go figure). Sure was fun, though. Getting a reverse crank for an ST46 was a trip.
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Randy,
Do you have any pictures of the ship? Now I'm getting a new bug - maybe if I take two aspirin?
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Today, I started applying dope to the fuse, and other parts that are to be painted. I got 3-4 coats of clear on the bare wood, applied the silkspan, and 3 more coats of dope. I sprayed a light coat of primer on the cowl, cabane mount, and wheel pants.
A long day, but it's going together pretty good now.
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That's a lot of dope for one day. Guess that is why it takes me so long. I think Sparky stated no more than two coats a day. %^@
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That's a lot of dope for one day. Guess that is why it takes me so long. I think Sparky stated no more than two coats a day. %^@
Yes indeed, perhaps too much, but this morning sanding out the cowl and wheel pants, it seems to be working out fine. Gordy has told me that applying dope this fast, doesn't allow for it to act like seperate coats, rather it acts like one thick coat.
I'm not sure, I've done it both ways, and they seem to be the same in the end.
I'm sure that doping, here in the dry high desert of Utah, is a huge difference from other areas. Absolutly no blushing, and we have a strom headed our way. Below 30% humidity does make a difference.
Today, I've started making fillets, and tightening up the seperation lines for the various take apart options. Pictures laterr. H^^
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I spent much of the day yesterday, finishing the cockpit details, and installing the canopy. I just included the basic details, like a pilot, and dash board.
I'm installing the fillets. I'm using two types of fillet material, Super-Fil, and Epoxy-Micro-Balloons. I'm also using these materials to set the gaps on openings with a technique I learned years ago from a magazine article in an RC magazine. If you look closely, you'll see that the roots of the lower wing have Saran Wrap tightly covering them, and the fillets extend out over the plastic. When the wing is removed, and the wrap is gone, the fillets will provide a tight separation line between the wing, and fuselage. I'm using the same technique on all separation lines, to minimize the gaps.
Today, there will be more work along these lines.
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Oh no!!! Something learned from RC. Yes I learned the same thing years ago when I was playing with the twiddly sticks. H^^
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Will,
Well, I did have pictures, but a hard drive crash several years ago took care of that. No backup - go figure. I may have a pic in a box somewhere. I need to go through some old boxes of pictures to see what I can scan in.
Looks good, John. I await the final result with bated breath (not baited breath).
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It's getting close, today all fillets were installed, and the canopy was blended in.It's all drying right now. I really like the Super-Fil, it works as advertised.
Tomorrow morning it should all be good and dry enough to sand out really well. I expect to be spraying on a coat of primer. H^^
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John,
Yep, the SuperFil is nice stuff. Can't wait to see the final product. Looks really good to this point.
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Here are pictures of yesterdays work. Fillets installed, canopy blended, and such. To days chores are to get a coat of primer in place, and if it dries fast enough, some wet sanding.
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AAAALLLLLLLLLLL righty, the primer is on. I want to start wet sanding, but I know I'd best wait for it all to dry real good.
The cowl and wheel pants have the base coat on.
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The base is on. Letting it dry overnight before masking.
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Ya know, John, this is possibly the coolest plane you've ever built. Very nice.
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Blush, Thanks Randy, for the compliment.
I got some trim masking done today, and the first trim color applied. It was raining, so I got some blushing. I'll apply another coat tomorrow which should take care of it. Two more colors to go. #^
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Ya know, John, this is possibly the coolest plane you've ever built. Very nice.
At least from the ones I've seen, I would have to agree. It's going to be real interesting to hear how this one flies. y1
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Thanks guys, It's coming out OK, not as nice in person as it looks in pictures, but that seems to always be the way it is. I'm struggling with weight buildup at this stage. It's now looking like somewhere between 68 and 70 Oz's. I wanted 60 or less. I've already designed new larger wings to bolt in to give me a better weight to sq inch ratio.
I'm looking at changes to make to trim some weight from the fuselage.
I still have hopes for a great flying plane, even if it's on the limits due to weight.
Today, I'll be masking and applying the last trim colors.
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Lookin' good, John. The plane, that is! Did you ever decide what powerplant to use for this'n? I'm hoping for the Stalker .81, of course. H^^ Steve
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Thanks Steve, I'll be starting out with the Stalker .61. Gordan has the .81 now, mounted in his Tony. I'll see how it goes for power with the .61, then, if I need more, I can go to the .,66 easily, or up to the .81. I tried to talk Gordy out of his RB .76, but he just won't let me borrow it. (He knows he won't get it back I think.)
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Well, I got the trim on, but have a lot of touch up due to problems between the coats. Still, it doesn't look too bad in pictures, but I've a few days of work needed to fix the problem areas. I've got to let it dry a day or two first.
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Looks very good John. I like it a lot. Can't wait to see it live and in person.
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While I'm waiting for the trim paint to dry thourouly, I can finish up some details such as mounting the hinges, finishing the covering at the bottom wing roots, Get some thinned epoxy into the engine compartment, for fuel proofing, and a bunch of other small issues.
Thanks Randy, and others who have offered encouragement with this project. #^
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And John, jump straight to the .81. You can't have too much power. ;D
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You can't have too much power. ;D
I would heartily second that opinion. y1
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and I third it!
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I hear you guys. I'll have to start out with the .61 first, since I no longer have access to the .81. If I need more, I'll have to purchase a new one. H^^
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I hear you guys. I'll have to start out with the .61 first, since I no longer have access to the .81. If I need more, I'll have to purchase a new one. H^^
I have a like new ( about a dozen bench runs and 3 flights) Stalker 76 available if you are interested.
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I've been busy. It took a little longer to touch up the trim. I wound up sanding most of it off, and redoing the entire finish. I had to deal with a little bit of compatibility problems with the paints of choice. They go over each other fine, but one, butyrate dope, doesn't seem to lock as tight to the base as I would like it to.
I kept having problems with trim olors lifting, but eventually, I got it all on, and it's good enough that I can live with it.
Whoever said, "Painting is never finished, just abandoned", was soo right,
I'll be applying clear dope over the entire finish job tomorrow. I'll post pictures showing the assembly sequence, ending up with the completed plane. H^^
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o2oP ;D
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Man, I can hardly wait for the flight report! My old bipe in the late 60's and early 70's flew with much authority on my old Fox 59, John, so try the 61 and see whahoppens! It had a wing area in the 700's. The closer we get to the possibility of available plans and maybe a short kit, the more excited I get. #^ #^ %^@ HH%% HH%% CLP**
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Drat, I ran into more paint problems while clear coating. HB~> It looks like it's going to be a day or 2 before the clear is finished. Here's a teaser though. S?P
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John,
Boy don't I know. anytime you are using incompatible paint (or even the same paint but change something half way through), you are taking a chance. Mechanical or chemical lock (or both) is the best way to go, but I've had finishes that were a lot less than that. I just fixed the finish on my current plane. When I pulled the tape, it peeled up clear. And this was a plane that has been flown for a year. Sheesh! It is catalyzed polyurethane over a dope base.
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Well, it's a comnbination I will think twice about using next time. Third time seems to be the charm, and if it isn't, it'll have to do. HB~>
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Probably more with painting more than anything else, I've decided that if you have a combo that has worked well previously, repeat.
I try to follow the "If it ain't broke, don't fix it" philosophy. ;D
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Well, for better or worse, it's all but finished. A few minor clearance problems and such left but it's done.
It's a bit heavier than I would like at 72 Oz's. The good part is that the CG seems to be about right, fore and aft, and the vertical CG also seems to be about right.
Here's some pictures of the assembled airfame. H^^
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John,
Absolutely gorgeous!!!
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Looks great John, can't wait to hear how it flies! y1
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Them cheek cowls look really cool.
I have a profile Steaman built about a year ago. Also converted a SIG Ultimate Fun Fly bipe for c/l.
Both are squirrely in the wind, I would make first flights on calm day only.
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Very cool, John. I can't wait to see it in person. Hopefully you can make one of the season's remaining contests over here. It is a showstopper.
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Thanks guys, for the positive comments. Allen, I appreciate the heads up, and will make the first flights with out lots of wind. Randy, I really hope to make it for one of the contests left in the NW this season.
I've a few little details that need attention, but I suspect the first flight should occur around the weekend. I've mixed emotions awaiting the flight testing.
I spent some time last night working out a new set of wings that will plug in to improve the area/weight ratio, just in case.
Cheers H^^
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You sound like me. I'm always whining about a plane's weight or whatever. Pat Johnston is always telling me to quit worrying and just fly the thing. Trim it the best I can and try to make the next one lighter.
He's right, I suppose (drat it).
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I like it, John! I like the cowl a lot, but I'd prefer a grey tinted canopy. The green canopy reminds me of the green welding glasses I got to fly with. One flight cured me! Made me feel a bit green around the gills. Good luck with the first flights and c'mon up for a contest sometime soon. H^^ Steve