Noob Question on Coax Copter

Hey out there.
I have kicked around the idea of a coax copter for a while and this past weekend started designing on…at least in my computer. When something struck me.
I know how it turns. Moves forward or back, left right and yaw…
But how does it stay level. On a quad to keep it level you spin up or down the motors on the corners to raise that corner or lower it…but a coax copter has not corners… So how does it stay level…

Things that make you go hmmmmm

Hey Ricky,

The single and coax copters use four servo-controlled fins on the bottom that deflect the flow of air from the prop(s) to make pitch and roll forces.


Thanks Paul.
So those controls are sufficient to keep it level.
I ask because I am in the process of designing one.


Yes they are, provided they are large enough. I increased the size a bit after a few test flights.

Interesting. So it needs more command authority I guess.

So I have a design my computer I am messing with. I think I will make the vanes larger.

Nice coax. Will the electronics be inside the body?

I would make the vanes stick out below the bottom of the body - at least a little bit.

What material will it be?

Mine shown above was a single copter. I’m tinkering with a coax now and have test “flown” it on a tether hanging from the ceiling.

Very cool stuff.
Yes I will make the vanes longer. I designed it to be 3d printed. In theory anyway.
Yes the electronics will be inside. At least in theory.
I also designed it to be able to change the vanes if needed. I am just test printing various bits for size and fit. Almost ready to get some spools of PLA and start at it.
Thanks for the input. It’s an interesting project.

A little progress.


Really cool stuff Ricky.

Bit more progress.
Gawd I love building stuff lol

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Got the GPS segment printed over night and the segment to the right is now printing… That just leaves me with the two rear segments and then I can start assembling.

So Close.
Just 2 segments left. One is on the printer now and then tomorrow the last segment.
Just need my bits to arrive from China.

I know when I got to glue up the lat two parts I am going to have trouble…every little error in the assembly will plague me in the final gluing.

Ring is finally done

Made the flaps this past weekend.

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Cool. Can’t wait to hear how it performs. I think my next one will have a shorter body like your coax. It will help to keep it from tipping over on landings.

I have no clue if it will work. But it’s been fun so far.
I have learned a ton about how to design it, print it. The mistakes. The things that could be done better.
I mounted the lower Flap support today. If I can this coming weekend I will cut the motor mounts. The motors are apparently at the post office. So a step closer.

My fear is it just becomes a big hover craft.

Lots more to do.

A little puttering around this evening.

Well that worked out better then I thought.
I need to finish off the screws and trim some screw heads. but looking good.

Got the landing skids installed today


Any update to this project? I just stumbled upon it and it looks really neat. I’ve always been fascinated with coax copters, maybe one day ill get around to building one.

The thing that intrigues me about this design is how flat and wide it is. Id imagine tuning may be a bit of a nightmare with the mass of those batteries so far out and the fins being so close to the CG. I’m curious how Arducopter handles the challenge.

Hey James.
Thanks for the interest. Tuning wasn’t a problem…lol I could never get it off the ground.
I am thinking of redrawing and printing it with a lighter form…IT looks really cool…but alas to heavy.