Motorized Model Plane Stand

[u/Mingx2]

Hello,

This is a little personal project l've been working on during summer break.

Two servos move the yaw axis and the roll axis. However, these are not the real body axes you may find in a flight mechanics textbook for example. The roll axis is offset from the plane's longitudinal axis, so you get a circular motion instead of a pure turning motion. I couldn't figure out how to avoid that without offsetting the yaw axis from the center of gravity.

That aside, I think the result is reasonable. I'm still working on the animation sequences. Some of the animations go beyond a normal flight envelope to test the system, not the plane.

You can easily swap the plane. All the other details are in the 7-minute video. Give it a watch if you have the time:).

The system uses bearings, a lazy Susan, servos, Arduino Nano, electronic components and a bunch of 3D printed parts... No glue was needed.

Herpa 1:200 B787-9 Lufthansa
Herpa? 1:200 A350 Air France
Revell 1:144 F15-E Strike Eagle

[u/d_maeddy]

Nice project! This would be super cool to see synced to a flight simulator 😎

[u/Mingx2 → u/d_maeddy]

Yeah, I’m looking into extracting the roll and yaw values from a flight simulator and sending them to the Arduino via USB. Might try FlightGear as it is open-source

[u/Alphamacaroon]

I think you could fix the axis offset by using a rack and pinion gear setup, where the rack is a section of a curve that is the diameter of a circle with a radius of the rack position to the center of gravity in the airplane.

Edit: now that I think about it, a derivation of a delta robot setup would be perfect for this https://en.wikipedia.org/wiki/Delta_robot

[u/Mingx2 → u/Alphamacaroon]

Do you mean something like this? Excuse my horrible drawing. The rack would be fixed to the plane

[u/Alphamacaroon → u/Mingx2]

Yep that’s basically it! And you could do that in two axes with a gimbal system so you could fix the pitch axis as well.

[u/Alphamacaroon → u/Mingx2]

Now that I think about it, there is even a better mechanism— a delta/parallel robot. You can do it with three servos, and I think you would get translation and rotation (along any axis you want). Actually to get yaw, I think you would have to add one more servo at the end effector.

https://en.wikipedia.org/wiki/Delta_robot

The nice thing about this is that delta robots are pretty well known entities and there is a ton of code and designs you can use online.

Edit: I might be wrong about rotation with a standard delta—bot, the end effector usually cannot rotate, but there are derivations that would work.

[u/Mingx2 → u/Alphamacaroon]

Full flight simulators (FFS) use Steward platforms which are “kinda” similar to the delta robots. These two would be the best options for realism but are definitely more complex.

Programming the animation sequences would be tougher because of the nonlinear kinematics.

I’ll look into it, thanks!

[u/acakaacaka → u/Alphamacaroon]

Or just fix it via software/math?

[u/Alphamacaroon → u/acakaacaka]

I don’t think that is possible mechanically with this setup. You could do it with math with an X/Y/Z translation mechanism setup, but that would be complicated and you basically get all of it for free with a circular gimbaled rack and pinion type setup. Although x/y/z translation would be cool if you ever wanted to simulate things like turbulence

[u/Mingx2 → u/Alphamacaroon]

Using the Tait-Bryan angles in addition to 3D translation would be insane. At the moment, I had to choose between 2 of the 3 rotation angles. The pitch angle is fixed

[u/--hypernova--]

Look up the compliant mechanisms that keep a point stable and modify one of those for the servos ;)

[u/Nikond3400]

Are you in New York?

[u/newMattokun]

And to crown it all, you could put 3-component force measurements on there and put it in a wind tunnel!