1938 "Twin Cyclone" Free Flight to RC conversion

[TooJung2Die]

Damn I can't read. That's really cool!

You didn't miss anything I wrote but I thought someone might ask about the torsion rod. You asked an excellent question, one I've been asking myself ever since I bought this kit two years ago. It was only recently I remembered how we controlled the rudder using a torsion rod back in the days of escapements and pulse proportional RC. Then it dawned on me how to use a similar mechanism to connect two rudders.

 

[TooJung2Die]

Time to make airplane noises. Taped it together for the required bare-bones photo shoot.

I decided to go full blast old timer and cover it with tissue. I was hoping the kit tissue was silkspan but it has no wet strength. I might have some silkspan around here... If I have to I'll use ordinary art tissue.

Jon

 

[rockyboy]

Looking great!

 

[speedbirdted]

I love that Willy Nillies motor mount.

 

[TooJung2Die]

I love that Willy Nillies motor mount.

Ain't it a hoot!? The one I put on the Eaglet definitely causes some double-takes. I have another old timer I built a couple of winters ago, the "So-Long", that would look much better with this glow engine motor mount. I don't think anyone but Willy Nillies is making them.

 

[speedbirdted]

I think I saw someone in the FB group 3D printing them. Did they release the STLs somewhere? Or someone else just made their own model and used that.

 

[TooJung2Die]

No doubt there are people out there with 3D printers making motor mounts similar to these. That's probably where Willy Nillies got the idea. But for folks like me without 3D printers Willy Nillies is the only source I know of. I'm still trying to think of a compelling reason to get a 3D printer. So far everything I can think of making can be obtained somewhere else. They're kind of expensive to buy as a toy to play around with for making other toys.

 

[rockyboy]

No doubt there are people out there with 3D printers making motor mounts similar to these. That's probably where Willy Nillies got the idea. But for folks like me without 3D printers Willy Nillies is the only source I know of. I'm still trying to think of a compelling reason to get a 3D printer. So far everything I can think of making can be obtained somewhere else. They're kind of expensive to buy as a toy to play around with for making other toys.

WN does a great job with these little motor mounts, and it's not an easy thing to get setup to print well. Very tight tolerances on the mounting holes to get the screws to go through, and the multi-color / multi-part prints take a while and some skill to produce right. I have a 3D printer and still find it well worth the couple bucks to order these mounts rather than deal with making them myself.

 

[speedbirdted]

Eh, don't buy a prebuilt printer. Building one up from components is more fun and less money, plus it kind of automatically teaches you all the troubleshootey stuff that you need to do when printers decide not to work as intended.

 

[The Hangar]

Time to make airplane noises. Taped it together for the required bare-bones photo shoot.

View attachment 168344

View attachment 168345

I decided to go full blast old timer and cover it with tissue. I was hoping the kit tissue was silkspan but it has no wet strength. I might have some silkspan around here... If I have to I'll use ordinary art tissue.

Jon

Sweet!

 

[TooJung2Die]

Covering the fuselage. The tissue in the kit has the wet strength of toilet paper. This white tissue has enough wet strength to smooth it out over curves.

Side view.

I found a source for silkspan in my state and I wrote to see if they're shipping. No answer so I'm using what I got. I'm learning that good tissue has a dull side and a shiny side. The fibers are fine and if you look really close there is a crosshatch watermark. The best test is to wet it and see how easily it falls apart.
Jon

 

[TooJung2Die]

Moving on to covering the wing. I used glue stick to attach the tissue around the edges and the ribs. Then I seal where it needs to attach with thinned Eze Dope. It's sticking well to the undercamber after shrinking.

Jon

 

[speedbirdted]

That's some weird looking doculam you got there

I need to do a tissue build myself. I've never been great at it but it's something I'd like to practice, certainly.

 

[TooJung2Die]

That's some weird looking doculam you got there

You noticed? When I restored the "One Nite" I covered it with tissue; first tissue job in 45 years. I really enjoyed the task though I had to strip and re-cover the wing and tail feathers a number of times until I got the hang of it. I enjoy working with tissue a lot more than iron-on film.

Top side of the wing. I knew I couldn't cover the wing tip with a single piece of dry tissue without getting crows feet wrinkles around the edges. So I wanted to see how much this tissue stretches when damp. I applied the glue stick around the outside. Then I misted the paper very lightly with water, just enough to make it sag. It worked! I very gently pulled the tissue taut over the outer rib. When the tissue started to shrink before I had it perfectly smooth I lightly sprayed it again. Working slowly and very carefully the tissue wrapped around the wingtip without any wrinkles.

Top of the main section of the wing, covered and prior to wetting and shrinking.

Completed wing. No wrinkles.

I am very worried I will accidentally puncture this before the first flight.
Jon

 

[rockyboy]

That tissue job looks great! Nicely done!

 

[TooJung2Die]

That tissue job looks great! Nicely done!

Thanks, I think it's the best tissue covering I've done to date. This is my favorite part. Give the tissue two very light coats of Krylon Crystal Clear. The tissue becomes see-through translucent. The spray finish also adds some strength and tightens it up a little bit more.

Jon

 

[TooJung2Die]

Since there's no way to mask tissue without damage you have little choice but to free-hand paint. I kept it simple with all straight lines. Next step is to assemble it into an airplane!

I used monofilament fish line for the rudder hinges. The rudders are balsa sheet and I didn't want to use tape hinges. Fish line works well, not as floppy as Tyvek, but it is too hard to slot 1/16" balsa for Tyvek CA hinges.

 

[The Hangar]

Since there's no way to mask tissue without damage you have little choice but to free-hand paint. I kept it simple with all straight lines. Next step is to assemble it into an airplane!

View attachment 168931

I used monofilament fish line for the rudder hinges. They're only 1/16" thick and I didn't want to use tape hinges. Fish line works well, not as floppy as Tyvek, but I doubt I can slot 1/16" balsa.

It looks super sweet! How are you hooking up the twin rudders? (You probably said earlier and I missed it...)

 

[TooJung2Die]

It looks super sweet! How are you hooking up the twin rudders?

Thanks!
This is how the rudders are controlled.

The individual rudders are a bit on the small side but combined there should be enough rudder authority. Aerobatics are not planned, this is basically a powered glider. The elevator is hinged with Tyvek, there is enough wood thickness for CA hinge slots.

Jon

 

[speedbirdted]

Thanks!
This is how the rudders are controlled.

View attachment 169018

View attachment 169019

The individual rudders are a bit on the small side but combined there should be enough rudder authority. Aerobatics are not planned, this is basically a powered glider.

Jon

Clever! Though I think I would have made it a little more discreet by putting the rod that goes between the two rudders on the underside of the elevator, and then control the rudders via their own very small torsion rods that extended below the horizontal stabilizer inside of the rudder. Your solution is probably lighter than that though.