Hey everyone, I would love to get your opinions on this concept...

I am working on a rotary wing design, and this is a monocopter version of it.  It has only two moving parts, the two propellers.  The two props drive the wing around an avionics hub while also controlling the pitch of the wing throughout the cycle through differential thrust.  The battery is used as a counterweight.

The symmetrical airfoil is stable, so it should not put up much of a fight as far as pitch control goes.  If you are wondering about the motors ability to go through throttle changes fast enough to execute a cycle for every rotation, many monocopters already use cyclic throttle pulses to maintain control.

The advantages would be:

1. The elimination of servo cost, weight, complexity.

2. Direct, structurally efficient cyclic pitch control over a larger wing, current systems use a servo to control the pitch of a very small wing, and usually just a control surface on the wing.

Views: 1200

Comment by Gary McCray on October 15, 2016 at 8:08pm

Hi Joe,

You follow in the footsteps of one of our most illustrious members.

Jack Crossfire did this a long time ago, practically prehistoric in terms of what is possible now.

That he got it to work with the tech available back then was nothing short of magic.

But if you check out some of Jacks posts you will see he is truly a bit of a wizard in any case.

Best Regards,


Comment by Peter Seddon on October 16, 2016 at 4:08am

Try this paper for more info on controlling monocopters. Would a control surface not be a simpler, more responsive, lower weight way to get the cyclic pitch control? 

Fly-by-wire Control of a Monocopter
Spring 2008

James Houghton and Woody Hoburg


Comment by Joe Renteria on October 16, 2016 at 9:59am
Hey Gary, I have seen probably all of Jack's video, would love to know what he knows...
Comment by Joe Renteria on October 16, 2016 at 10:09am
Thanks Peter, I will have a look at that. From what I am reading here and there, I believe that response time should be just fine. Eliminating the servo and control surface would make for a simpler and more robust device. I also don't think that a small and lightweight servo will last very long if it has to move a surface once per cycle.
Comment by Joe Renteria on October 16, 2016 at 10:12am
Also, I think that moving the entire wing will provide better response than just a control surface.
Comment by Nikola Rabchevsky on October 16, 2016 at 1:54pm

I would think takeoff and landing would be a challenge.

Comment by Joe Renteria on October 16, 2016 at 2:30pm
Hi Nikola, yes it is an issue. Usually there is some odd landing gear or launching platform used. It would be great to build one that you could just toss up to launch...


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