Author Topic: Build: Cartoon-scale Mooney Mite (Read 28142 times)

Tim Wescott · « **on:** November 15, 2015, 06:26:49 PM »

My wife's learning how to fly, so I'm trying to build faster than she can crash. I've got a bunch of Phil Cartier's Psycho III cores, so I'm building planes that work with those. If she stops crashing before I run out of cores I may even build some combat planes!!

The fuselage is basically what I need to hold a motor and hold the tail out from the wing, but I figure that while I'm at it I may as well scratch the scale itch, so it kinda-sorta looks like a real plane, maybe.

I'm not going to spend a whole lot of time taking pictures, but here's a shot of the assembled wing (Phil's cores with LE balsa and spars) with the tail feathers leaning against it, next to the fuselage which is still clamped and weighted down from being glued together. There's no wing cutout in the fuse yet -- I plan on doing a rough CG estimate first, then whacking out the wing cutout.

The wing's on the bottom of the fuse instead of the middle, because the leadouts and bellcrank will go on top of the wing, 1/2-A sheet trainer style.

Hopefully it'll be fun and not too heavy -- I'm planning on using a Magnum 36 that Steve Helmick gave me (along with a very short-lived plane) to power the thing.

Randy Powell · « **Reply #1 on:** November 15, 2015, 06:29:34 PM »

And is the Legacy done yet? I expect you to have a competitive plane next season, dude.

Tim Wescott · « **Reply #2 on:** November 15, 2015, 06:43:46 PM »

Quote from: Randy Powell on November 15, 2015, 06:29:34 PM

And is the Legacy done yet? I expect you to have a competitive plane next season, dude.

No, this is the latest Legacy lag. I have Paul's Atlantis, which I'll fly next year if the Legacy isn't done. Yes, I need to finish the Legacy -- but there's a good chance that a 30 year old plane of Paul's will teach me more, at least in the short term.

I don't expect the build to take long -- between Phil's cores and not worrying too much about looks I should be able to toss a nice plane together quickly.

Mark Scarborough · « **Reply #3 on:** November 15, 2015, 07:54:52 PM »

Tim,,
focus man,, I am coming after you LOL

so did you power up the Cardinal for her? or is that waiting for a bit further down the learning curve?

GET THE LEGACY DONE

Russell Shaffer · « **Reply #4 on:** November 15, 2015, 08:00:27 PM »

I covered the wing on my Joe Just Wildcat with polyester dress lining secured with polycrylic. It didn't seem to add too much weight and it makes a strong wing . Fun project you have going.

Tim Wescott · « **Reply #5 on:** November 15, 2015, 08:22:15 PM »

Quote from: Mark Scarborough on November 15, 2015, 07:54:52 PM

Tim,,
focus man,, I am coming after you LOL

so did you power up the Cardinal for her? or is that waiting for a bit further down the learning curve?

I'd already started on this when the Cardinal came into my hands, so I figured I'd stay on that road. And besides -- she's still at the point where every other flight ends up with a plane in the shop. I figure that a big solid foam wing is going to be a lot easier to fix than the Cardinal wing, making the repair times shorter.

(It's been raining a lot, but she got out to fly last week. The plane was new to her, and adjusted to pull up a bit. She came unstuck, went up, and up, and up, and oshitoshitoshit -- when it was vertical or a bit over she cranked in full up and didn't hit the ground. It's not the first time she started a figure 9 from takeoff, but it is her first save. So, she
GET THE LEGACY DONE

I'd already started on this when the Cardinal came into my hands, so I figured I'd stay on that road. And besides -- she's still at the point where every other flight ends up with a plane in the shop. I figure that a big solid foam wing is going to be a lot easier to fix than the Cardinal wing, making the repair times shorter.

(It's been raining a lot, but she got out to fly last week. The plane was new to her, and adjusted to pull up a bit. She came unstuck, went up, and up, and up, and oshitoshitoshit -- when it was vertical or a bit over she cranked in full up and didn't hit the ground. It's not the first time she started a figure 9 from takeoff, but it is her first save. So, she's getting better.)

And yes, the Legacy needs to get done. Current priorities, in order, are: house payments & food, keep wife in airplanes, get the Atlantis flying, start back on the Legacy, everything else. Getting the Atlantis really flying is close, keeping the wife in airplanes should taper off soon, and then I can get work done on the Legacy.

Tim Wescott · « **Reply #6 on:** November 20, 2015, 03:33:02 PM »

Engine bearers and nose doublers (which are glued on but not yet prettified).

The bearers are 3/16" x 1/2" x 2", because that was convenient to the size of stock I have. I'd rather have 3/16" x 3/8". The plan is to bolt the bearers to the plane, and the engine to the bearers, so that should I get a wild hair and decide to change engines I can. Someone will probably demolish the plane before that happens, but what the heck.

Does any make engine bearers similar to this? It's tiresome, and beyond the capabilities of me and my equipment to do a really good job. No one makes 3/16 x 3/8" stock that I can tell -- if they did, I'd just get some and whack it off to length.

Edit: I just looked and realized that I hadn't included the picture.

Tim Wescott · « **Reply #7 on:** January 02, 2016, 05:51:18 PM »

Holidays get in the way of work, which then gets in the way of modeling. Oh well.

Got my bench all cleaned up yesterday, so that I can cover the tail feathers. I'm about half done -- the stab, one elevator, and half of another is done, the fin and the rest of the other elevator is left.

Here's pics of the painted fuselage and of the engine bearers in their native habitat with engine bolted on -- you can see how I'll be able to change engines if I feel moved to do so, and how the bearers spread the load of the engine over the maple motor mounts.

The fuselage is primed with a few of coats of Minwax Polycrylic. The first one is painted on as dry as I can to minimize warping, then the second and third coats are heavier. A bit of sanding, then some light Sig fiberglass over that (hopefully for stiffness). Finally, a coat of Rustoleum "clean metal primer" followed by a coat of white, all brushed on, and then a canopy, also brushed on. I didn't make any attempt to mask the canopy -- it's just painted on by hand.

Once the thing is ready to assembly I'll find the CG, then I'll locate the wing and cut out the saddle.

john e. holliday · « **Reply #8 on:** January 04, 2016, 10:00:11 AM »

Looking good.

Tim Wescott · « **Reply #9 on:** January 04, 2016, 10:59:23 AM »

Quote from: john e. holliday on January 04, 2016, 10:00:11 AM

Looking good.

If I could spend a normal amount of time in the shop I could get one of these done in a couple of weeks -- this long, drawn-out process is kinda frustrating.

Oh well, it's a new year, the days are getting longer, and we don't have wall-to-wall concerts to occupy our time.

Balsa Butcher · « **Reply #10 on:** January 04, 2016, 03:43:28 PM »

Just gotta say it, the Mooney Mite is sort of a "Cartoon Scale" full scale airplane. Good Choice!

Tim Wescott · « **Reply #11 on:** January 04, 2016, 07:13:30 PM »

I've decided that I'm going to try to get into the shop and do one thing each day, even if it's a teeny thing.

Today I marked the estimated balance point, so I can mark out the wing saddle and saw it out. The picture doesn't show it well, but the entire fuselage is sitting on a 1/4" thick brass block, sitting on edge on my work bench. Hopefully this'll put the wing close to where it belongs when the whole thing is assembled.

Phil Krankowski · « **Reply #12 on:** January 04, 2016, 09:12:11 PM »

So that is balanced on a block? Cool idea. I will have to remember this one.

Phil

Tim Wescott · « **Reply #13 on:** January 04, 2016, 09:58:19 PM »

Quote from: Phil Krankowski on January 04, 2016, 09:12:11 PM

So that is balanced on a block? Cool idea. I will have to remember this one.

Phil

Yes. I'd have balanced it on something round, like an X-Acto knife handle, but balancing it on a block means that it'll be stable (barely). You trade away some accuracy, but it's convenienter.

I forgot to mention, if it's not obvious: I've got engine, tank, tail feathers, etc., all located roughly where they belong. Except that as I write this I realize that I didn't get the WING put where it ought to be -- I'd going to have to correct that, and re-do. Oh Joy.

Randy Powell · « **Reply #14 on:** January 05, 2016, 05:06:41 PM »

So, the Legacy is on hold while you build cartoons.

Tim Wescott · « **Reply #15 on:** January 05, 2016, 06:33:08 PM »

Quote from: Randy Powell on January 05, 2016, 05:06:41 PM

So, the Legacy is on hold while you build cartoons.

Yup. Alas.

Chancey Chorney · « **Reply #16 on:** January 05, 2016, 07:39:47 PM »

After seeing the last picture, I think you may have tracking problems on take-off or landing...

Tim Wescott · « **Reply #17 on:** January 07, 2016, 04:04:06 PM »

Wing attach. This is a modification of Phil Cartier's recommendation for mounting his wings. He has you make a sleeve of 1/64 or 1/32 plywood around the wing, and mount that in the usual cutout on the fuse. In my case I'm mounting the wing on the bottom of the fuse so the leadouts can come out at the desired height, so I have a pad glued to the top of the wing (see the arrow). This pad, in turn, will glue to the cutout in the fuselage.

It's held up well in my Test Pig #3 (a cartoon-scale Cessna C-37), which can easily do the whole pattern, so I figure I'll be fine here. But if Robin rips the wings off in the outside squares, we'll all know who to blame (and it won't be her!).

Left to do before I marry wing with fuse is to glue the bellcrank mount to the wing -- I'm thinking a hefty plywood "washer" top & bottom with a dowel in between -- I'll drill for a #8 bolt (which is, conveniently, 5/32" diameter), and mount the bellcrank on top of the wing. If I'm thinking straight I might glue hunks of lite-ply onto the wingtips, as a mount for the leadout guide on the inboard tip, and a mount for the tip weight on the outboard tip.

phil c · « **Reply #18 on:** January 09, 2016, 03:38:52 PM »

Quote from: Tim Wescott on January 04, 2016, 09:58:19 PM

Yes. I'd have balanced it on something round, like an X-Acto knife handle, but balancing it on a block means that it'll be stable (barely). You trade away some accuracy, but it's convenienter.

I forgot to mention, if it's not obvious: I've got engine, tank, tail feathers, etc., all located roughly where they belong. Except that as I write this I realize that I didn't get the WING put where it ought to be -- I'd going to have to correct that, and re-do. Oh Joy.

For a cute trick balancing with the wing. Subsitute a chunk of something that weighs the same as the wing. Most wings have a CG right around 50% of the chord, a bit further back with big, clunky flaps. Add a pointer with the end where the CG falls relative to the 50% point of the wing. Or make the pointer long enough to locate the wing leading edge and mark the desired CG location on it. Slide for and aft until the fuselage and other bits balance near where the CG should go and mark the wing leading edge position.. A bit nose heavy is better. Tail weight has more leverage than nose weight.

Tim Wescott · « **Reply #19 on:** January 09, 2016, 05:05:04 PM »

Quote from: phil c on January 09, 2016, 03:38:52 PM

For a cute trick balancing with the wing. Subsitute a chunk of something that weighs the same as the wing. Most wings have a CG right around 50% of the chord, a bit further back with big, clunky flaps. Add a pointer with the end where the CG falls relative to the 50% point of the wing. Or make the pointer long enough to locate the wing leading edge and mark the desired CG location on it. Slide for and aft until the fuselage and other bits balance near where the CG should go and mark the wing leading edge position.. A bit nose heavy is better. Tail weight has more leverage than nose weight.

That's exactly what I did. Your cores balance much farther toward the front than 50%, BTW.

Tim Wescott · « **Reply #20 on:** January 09, 2016, 08:47:56 PM »

Bellcrank mounting. The bellcrank will be on top of the wing, held on by a long 8-32 screw. The mount involves a 3/8" hole in the wing right on the edge of the spar, a 3/8" dowel drilled out to 11/64", and two 1-1/4 plywood disks.

Tim Wescott · « **Reply #21 on:** January 10, 2016, 09:02:09 PM »

Maybe I could call it the "Mooney Might".

At any rate, in order:

The bellcrank marked out on the Phenolic Sheet of Destiny.
An interesting result in photographic science -- the top segment is the Phenolic Sheet of Destiny under fluorescent lighting, the bottom is the exact same sheet (from a different angle) with the camera's strobe light. Weird. I'm thinking that the spectrum off of a Xenon lamp isn't a nice even thing like the spectrum from the sun, that the phenolic's reflected spectrum also has "holes", and that the "holes" don't line up.
The end plates -- the left one is to mount the leadout guides, the right is for the tip weight (which, since this is a trainerish thing, I'm just going to screw on as I see fit)

Any plywood that's getting glued to foam is being done with lots of microballoons in the mix -- this is partially to save weight, since I figure that regular epoxy is way stronger than foam, and partially so that it doesn't show quite so bad. I'm not sure why I care about the latter, given that I'm not going for any appearance points on this one.

Phil Krankowski · « **Reply #22 on:** January 10, 2016, 09:42:11 PM »

Quote from: Tim Wescott on January 10, 2016, 09:02:09 PM

... I'm not sure why I care about the latter, given that I'm not going for any appearance points on this one.

Personal pride. Anyways isn't this meant for someone else?

Phil

Tim Wescott · « **Reply #23 on:** January 10, 2016, 10:43:28 PM »

Utilitarian is good in this case: it cuts down on regrets when she crashes.

Sent from my SM-G900V using Tapatalk

Curare · « **Reply #24 on:** January 10, 2016, 10:59:25 PM »

Oh man, I've been here before. Would said aircraft be a significant other?

I hope you've got some storage space for it, she'll fly it once, and then never fly it again, for fear of breaking it, and you wont be able to get rid of it, because you built it, and it just sit and rot for the next 10 years.

Ask me how I know!

Mark Scarborough · « **Reply #25 on:** January 10, 2016, 11:09:53 PM »

Quote from: Curare on January 10, 2016, 10:59:25 PM

Oh man, I've been here before. Would said aircraft be a significant other?

I hope you've got some storage space for it, she'll fly it once, and then never fly it again, for fear of breaking it, and you wont be able to get rid of it, because you built it, and it just sit and rot for the next 10 years.

Ask me how I know!

Actualy Tim has a different problem, she flies enough that he cant keep up with building while she is learning to fly...

Tim its coming along, keep in mind the first contest is only a few months away....
I know I am lagging on my new build,,

Tim Wescott · « **Reply #26 on:** January 11, 2016, 10:37:05 AM »

Quote from: Mark Scarborough on January 10, 2016, 11:09:53 PM

Actualy Tim has a different problem, she flies enough that he cant keep up with building while she is learning to fly...

Tim its coming along, keep in mind the first contest is only a few months away....
I know I am lagging on my new build,,

She's injured her wrist, so I'm getting a chance to catch up. Hopefully she'll be interested once she heals.

It looks like I'm going to be flying the Atlantis this year.

Mark Scarborough · « **Reply #27 on:** January 11, 2016, 11:25:27 AM »

did she hurt her wrist thumping you across the noggin? LOL

Tim Wescott · « **Reply #28 on:** January 11, 2016, 12:59:14 PM »

Quote from: Mark Scarborough on January 11, 2016, 11:25:27 AM

did she hurt her wrist thumping you across the noggin? LOL

Cleaning the bathroom, of all things. We had some persistent dirt on the baseboard in there that finally turned out to be glue (courtesy of the previous owners). She decided that it Just Had to Go, and worked at scrubbing it so hard that she injured some tendons. Her After Action analysis did concede that she should have changed tools (she was using fingernails) before she overstressed her hand.

She's getting out of a lot of work now.

Tim Wescott · « **Reply #29 on:** January 11, 2016, 09:53:19 PM »

Waiting for my epoxy to warm up enough to flow. It's definitely time to move all the glues into my office for the winter.

Tim Wescott · « **Reply #30 on:** January 11, 2016, 10:23:32 PM »

Fuse glued to wing & squared up vertically (with a square) and fore & aft (with a tape measure). Should be cured tomorrow & ready for tail feathers.

john e. holliday · « **Reply #31 on:** January 12, 2016, 11:22:29 AM »

Why were you letting her do a mans job?

I should talk, my wife completely remodeled our bath room. by the way Mooney is looking like a plane now.

Tim Wescott · « **Reply #32 on:** January 12, 2016, 07:33:16 PM »

Getting ready to glue on the stab. Here you see my home-made incidence jig with a level. I've blocked up the plane so that the wing is level, then checked the level of the horizontal stabilizer mounting pad (it's level). I'm about to peel some 'coat off of the horizontal stab and glue it on, hopefully getting it nice and level with the wing.

Avaiojet · « **Reply #33 on:** January 13, 2016, 11:28:47 AM »

Tim,

You picked a good color for the canopy. The model is looking good!

Steve Helmick · « **Reply #34 on:** January 13, 2016, 05:28:50 PM »

Tim, have you made a new tongue muffler for this one? If not...don't!!!!!!!

Steve

Tim Wescott · « **Reply #35 on:** January 13, 2016, 06:14:18 PM »

Quote from: Steve Helmick on January 13, 2016, 05:28:50 PM

Tim, have you made a new tongue muffler for this one? If not...don't!!!!!!! Steve

Not until I score a TIG welder, that's for sure.

Tim Wescott · « **Reply #36 on:** January 16, 2016, 07:10:18 PM »

Here you see the thing with the wings blocked level. The stab is checked for level both with a (cheap) machinist's level and by eyeballing up the fuselage to see if it matches the wings. The stab is verified square to the fuselage by measuring from the nose to each rear corner and tweaking things until the measurements are equal (33 7/16" in this case).

I was pondering how to clamp this thing up, when I realized that I could just screw it on. There's no way that screws into balsa would be strong enough for flight, but for holding everything in place while epoxy dries, they should be perfect. I'll take the screws off when the glue is set, then glue the vertical stab over the holes.

Tim Wescott · « **Reply #37 on:** January 17, 2016, 05:04:28 PM »

Fin. It's beginning to look a lot like a Mooney.

Tim Wescott · « **Reply #38 on:** February 06, 2016, 04:38:15 PM »

Getting the leadouts in. I still need to make the pushrod, glue the elevator in, mount the tank and tip weight, and slap on a bit of paint here and there for fuel proofing.

Oh, and wait for a break in the weather, of course.

The last time I made one of these "Use some Phil wings and build a plane" I got the leadouts a bit off vertically, and I can only fix it by whacking things up and re-gluing. This time I'm making that adjustable, so unless they need to end up buried in the wing I'm good. I'll probably find the right vertical location and then glue everything in place (or at least paint over it all).

Tim Wescott · « **Reply #39 on:** February 06, 2016, 06:04:17 PM »

Starting on the control rod. Yes, it's probably stupid to hand machine these from solid billet aluminum, at least for a freakin' trainer, but I like playing with my lathe.

My LHS is now selling arrow shafts, 6mm ID x 7mm OD. These are perfect for control rods. I bought four, because, well, because.

The rod ends are about 3/4" long, drilled & tapped for 4-40 screws, then counter-bored on the inside about 1/2" deep. The threaded bits you see sticking out are 4-40 machine screws that have been slathered with epoxy then screwed in there tight. These ends will be glued into the ends of the pushrod. It doesn't sound like enough, but I have yet to have one of these fail, with many flights and crashes.

Tim Wescott · « **Reply #40 on:** February 06, 2016, 07:56:17 PM »

I clamped the tail to neutral, with the clevis* in the middle of it's adjustment range. Then I marked the length of the pushrod by wrapping it with masking tape and using a pen to mark the location of the step in the rod end. Then I sanded the rod ends and the inside of the rod, mixed up some 30-minute epoxy, and put it all together.

If you do this, and if, like me, you don't drill a pressure relief hole in the rod, you need to clamp the ends on while the glue dries -- otherwise, the slight positive pressure from assembling the thing will push the ends out before the glue sets (ask me how I know!). Simply wrapping the ends in masking tape takes care of this, and masking tape adhesive usually releases pretty well from epoxy.

* Yes, I'm using a clevis. I know this isn't necessarily the most reliable means of doing a pushrod, but it's convenient and I suspect that this plane won't last long enough for it to become an issue.

Mark Scarborough · « **Reply #41 on:** February 06, 2016, 09:48:43 PM »

Looks like your having fun Tim,,

hows the Legacy coming along

Tim Wescott · « **Reply #42 on:** February 06, 2016, 11:51:39 PM »

Quote from: Mark Scarborough on February 06, 2016, 09:48:43 PM

Looks like your having fun Tim,,

hows the Legacy coming along

As soon as I get this off the building board I start work on the Legacy again. So you're kind of seeing Legacy progress here, in a backhanded sort of way.

john e. holliday · « **Reply #43 on:** February 07, 2016, 07:45:34 AM »

Some great info on doing the carbon ends. Nothing wrong using a good clevis as they are easier to move/adjust. A piece of fuel line will keep them from opening.

Mark Scarborough · « **Reply #44 on:** February 07, 2016, 11:25:27 AM »

Quote from: Tim Wescott on February 06, 2016, 11:51:39 PM

As soon as I get this off the building board I start work on the Legacy again. So you're kind of seeing Legacy progress here, in a backhanded sort of way.

thats like the engineers on the projects I work on,, they consider they are "working on the drawings" if they are driving to the office,, lol

Or cleaning house includes waking up and drinking coffee, ,

So is the wife geting back healed enough to start flying again?

Tim Wescott · « **Reply #45 on:** February 07, 2016, 12:24:10 PM »

Quote from: Mark Scarborough on February 07, 2016, 11:25:27 AM

So is the wife geting back healed enough to start flying again?

Very slowly. Which isn't fun for her (or me, since any chores that require a good grip are falling on me), but it does mean that I'm not scrambling to keep airplanes repaired.

Tim Wescott · « **Reply #46 on:** February 07, 2016, 06:30:10 PM »

Controls installed, tank mounted, hoses plumbed. It just needs some paint on a few patches of bare wood, some initial guess at proper tip weight (which I'm just going to screw onto a pad of plywood on the wing tip) and a test flight.

Tank's mounted on the inside. For starters I'm running a plain vented tank on muffler pressure -- we'll see what works in the long run. The only concessions to "pretty" in the tank setup are the holes drilled through the fuse for the hoses.

Tim Wescott · « **Reply #47 on:** February 09, 2016, 10:28:31 PM »

Ready to fly! And flying day is tomorrow, so we'll see how things work out.

It comes up to 43.2 ounces. That's not great, but it should fly OK for a trainer. It's about the same weight as Test Pig #3, which flies pretty well (for a sport/trainer) on the same wing.

The top picture is an odd solution to an odd problem. The tank is on the inside; rather than looping the tubes over the fuselage like my last such plane, I drilled holes. But the holes are full of balsa fuzz, and when I painted them they got much smaller. What you see there is a quickie tool I made by grinding a point onto some 5/16" rod. Push it through the hole, it shoves the sticky painted fuzz to the sides of the hole, and done.

It needed some tail weight. I decided that I'd get really classy and use a bolt. Even better, it's painted to match the plane. Folks will undoubtedly regret not being able to give the plane the appearance points it deserves.

Phil Krankowski · « **Reply #48 on:** February 10, 2016, 06:48:31 AM »

Is that fuel tank wedge your contraption or something purchased? Got a picture of the back end of the bracket without the landing gear in the way?

Phil

Tim Wescott · « **Reply #49 on:** February 10, 2016, 10:17:15 AM »

Quote from: Phil Krankowski on February 10, 2016, 06:48:31 AM

Is that fuel tank wedge your contraption or something purchased? Got a picture of the back end of the bracket without the landing gear in the way?

It's bent up out of .03" 3003 aluminum sheet. I'll try to get a picture of it later today.