Carbon bush plane design and build

[kirch93]

Hey guys!

Currently working on the design for a carbon fibre build. I love super cubs and bush planes, so its going to based around a cub. But not exactly scale. I'm looking to go full on STOL custom design.

Going to be spending most of the time working in CAD until the design is finalized, then hopefully I can build it!
Its all an experiment, I know what I'm doing in CAD but this will test my skills, and hopefully I can pick some up on the way.

Hope you guys enjoy!

So I started by choosing an airfoil, I have chosen USA-35B which was an original cub airfoil, and should work well.

I taught myself how to import points and use them to create a profile. (I am using durafly tundra for my scale.)



From there, I came up with some flap and aileron profiles.



The flap profile is going to be a double slot flap for maximum STOL awesomeness. This is unless it all gets too hard, then I can just use the aileron profile. Hopefully not though. I think I can get it to work.

The profiles were created using some pretty intense CAD methods to make sure if I want to change them in the future I can easily.



Let me know what you guys think!

 

[kirch93]

Just FYI, this is the inspiration for the mechanism.

https://www.youtube.com/watch?v=8O02OyxzAeU

And this the plane inspiration.

https://www.instagram.com/p/4h5fsoE_i7/?taken-by=bobbybreeden

 

[kirch93]

I spent some time working on the flaps mechanism. I came across a concept that was nice and simple, however hard to make at this scale.
This is the first concept



After that, I tried a simple double control horn setup, attaching to 2 points on a servo arm.
I think the final one will have this set up, maybe with a torque tube and 2 arms off it.

 

[kirch93]

Did some work on the whole wing design today. Its a lot of layout work, working out which profiles I need where. But it is coming along great. I have also come up with some building techniques too.

Basically I am going to glue a carbon fiber profile on each end of either foam or balsa, then sand it down to match the profiles. Kind of like hot wire cutting for someone without a hot wire. Then the whole lot will be covered in a layer of carbon fiber so it looks nice and is strong.

The control surfaces will have a shaft out either end, one being spring loaded. These will go into 2 holes in the wing to act as hinges, but keep them removable and also be hidden. I will show this in detail when I design it.

Here is some snaps of the wing so far. All the thin pieces are 3mm carbon fiber sheet and the wide pieces are the foam or balsa.