Thanks J. and all.

Wing is completely skinned now. Tip and leading edge next.

While I was waiting on the skin to dry today, I started on the stab. I want to see if I can make an airfoil shaped stab so cut me some cores and made some templates and tried hot wiring them. Turned out OK. One of them had a snag where the wire caught on a pin but I think it is usable. Pics of progress.

Jim

Pics.

Looks good. If I might inject here. You're going to find that on these WWII birds it's really hard to get the tail light enough. I do everything I can to keep the tail light and still wind up adding lead or a bigger battery in the nose in most of them. Might consider built up tail feathers next time.

J

Thanks for the advice J. The stab is only 3/8 thick in the middle and tapers to only about 3/16 at the tip. On such a small model I did not see how I could make a built up stab from foam. Could you explain how you would do it? Thanks.

Jim

Originally Posted by JIMA

Thanks for the advice J. The stab is only 3/8 thick in the middle and tapers to only about 3/16 at the tip. On such a small model I did not see how I could make a built up stab from foam. Could you explain how you would do it? Thanks.

Jim

I did the same thing. The stab is just way to thin to make it built up.

Yeah, I forgot about the size. Probably isn't easy in foam. You could always build up with balsa and use Doculam to cover. Really the only point I want to make is that an oz in the tail equates to about 3 or 4 oz in the nose to balance. WW II birds are just difficult unless you hang a big radial on them.
I'll be fighting the same thing in my big Buffalo and to complicate it further the stab is elliptical. Still haven't decided how I will approach that.

J

I tried to build light built-up stabs with the 40 inch Thunderbolt, horizontal stab is 16 inches, vertical is 6 inches. Both stabs total weight is under an oz. using 1/16 th ribs and 1/32 sheeting. Strong and light. Designed the crutch with the ribs which makes assembling fast an easy, some details in the build log.

https://www.rcgroups.com/forums/show...ed-to-40/page8

Michael

That's interesting. If the foam one doesn't work out, I'll keep it in mind.

Progress for today. Had an oops on the wing. Poked a small hole in the skin. How would you guys fix it?

Originally Posted by J Morgan

Yeah, I forgot about the size. Probably isn't easy in foam. You could always build up with balsa and use Doculam to cover. Really the only point I want to make is that an oz in the tail equates to about 3 or 4 oz in the nose to balance. WW II birds are just difficult unless you hang a big radial on them.
I'll be fighting the same thing in my big Buffalo and to complicate it further the stab is elliptical. Still haven't decided how I will approach that.

J

Cob, Jim, I'm not familiar with foam types or thinknesses, but..how about with an elliptical shape you laminate the outline with balsa. This would have to be elevated during construction. I suspect balsa hinge/spars are tapered. Foam ribs and the structure skinned with thin Depron? Like I said, I do not know the types. Tissue and Mod Podge flat for surfacing. Atleast, if I ever attempted a foam/balsa structure, I think that would be the way to get a light struture that would still use the higher percentage of foam. Then the tissue and Mod Podge would skin stress it lightly.

Fuzz

Another cool project Jim, following

D-Rock

Jim,
Depends on how big? Small hole and spackle might fill it. A large hole,I cut the hole out in a squarish shape then use a thicker piece of foam approx same size but cut with tapered sides. That way you can spread some glue on the patch, shove it down and let it dry. The tapered sides let it tighten up in the cut out hole. Then just use a snap off blade to slice it close to the surface. Sand and you're done with it and ready to move on.

Fuzz,
That's basically how Bates has designed the elliptical stab and I'll probably wind up doing it that way.

J

Originally Posted by J Morgan

... and to complicate it further the stab is elliptical. Still haven't decided how I will approach that.

J

Just a quick info post re: elliptical hot wired foam cores.

See attached PDF. Had to zip it because of file size.

Tom

Originally Posted by T_om

Just a quick info post re: elliptical hot wired foam cores.

See attached PDF. Had to zip it because of file size.

Tom

Tom,

Got a link to the native file? For some reason I can’t get this to download on my iPad, and I’m suffering on vacation for a week away from the real PC.

Thanks for that Tom. You I'm actually old enough that I remember when that was in a flying mag.
May give that a go on the Buff stab.

J