Fixed Pitch Drone/Heli Hybrid Custom Design

Youtuber Tom Stanton created a helicopter with a "virtual" swashplate controlled by speeding up and slowing down the main motor. Watch this video.

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Interesting Design That Actually Works

Youtuber Tom Stanton created a helicopter with a "virtual" swashplate controlled by speeding up and slowing down the main motor. It's explained more below, but this helicopter only has two motors and no complicated mechanical parts. He wanted to create a helicopter that was mechanically simple, but controlled via software similar to how drones are able to fly with multiple motors. Here's the explanation on how it works:

"The main rotor’s motor is equipped with a sensor that lets the controller know its position twice every rotation. By very precisely controlling the motor speed throughout each rotation — from very quick to nearly stopped — Stanton can change the blade pitch angles at the exact point necessary to steer the aircraft. It is amazing to watch and an ingenious implementation of physics, resulting in a surprisingly practical way to fly" - Hackster.io

Be sure to check out the video below, it's a great watch and interesting to see the process used to create this heli.

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Jul 15, 2020, 05:38 AM
Registered User
Hi, a direct drive motor system close to the head is a good idea and has a very cool appearance! But people here like collective pitch systems for 3D flights. In Japan , some inventor, Mr. Nakamura who invented HIROBO XRB and SRB , made a swashplate-less SRB ten years ago:

世界初!!!フライバーレス・サーボレス・スワッシュレス 電動ヘ&#12522 (2 min 3 sec)


But he gave up commercialization. I believe Tom Stanton's idea will be appreciated by the company for US military micro drones.
Last edited by K2-tokyo; Jul 15, 2020 at 05:46 AM.
Jul 17, 2020, 11:09 AM
Registered User
Congrats to Mr. Stanton! Impressive

Is there more information about how Mr. Nakamuta’s system works?
Jul 17, 2020, 07:33 PM
Registered User
Quote:
Originally Posted by lgibjones
Congrats to Mr. Stanton! Impressive

Is there more information about how Mr. Nakamuta’s system works?
Hi, no other information is available.
Jul 21, 2020, 06:32 PM
Registered User
Cesco's Avatar
I would like more info on Mr. Nakamuta system too. If i remember correctly it used a torsion bar in the head to change cyclic?

I think direct drive is a bad idea because it needs a heavy motor. A geared setup can have a much smaller and lighter high rpm motor. This is the reason direct drive did never sell with RC helis.

The rotorhead is great, i wish i could buy or construct such a thing for my own experiments.

Stanton does measure the rotor position by hall sensor the "analog" way. I think this can be done much simpler.

Stanton does the power modulation by sending the ESC multiple values per rotation. He uses a 500hz he says. I bet he didnt remove the ESC input smoothing. I can tell you how on "old" open source esc's
Last edited by Cesco; Jul 25, 2020 at 03:36 PM.
Jul 21, 2020, 06:53 PM
Registered User
Cesco's Avatar
Stanton's second vid:
How I built a Swashplateless Helicopter (9 min 23 sec)
Last edited by Cesco; Jul 21, 2020 at 07:15 PM.
Jul 24, 2020, 08:55 AM
c/f
c/f
Registered User
If the battery energy density is the available Horsepower, and the means to an end rotor requires "X" horsepower, I doubt the sum of mechanical weights penalty, "all inclusive" whether geared or direct would be different all that much if designed specific to available HP required.
Latest blog entry: Times up,,......
Jul 25, 2020, 09:30 AM
Is what I'm doing helping?
Steve_'s Avatar
This is cool, but I don't see any application for it.

The fact that you are fighting the momentum of the motor, shaft and most of the head
to activate pitch changes "x" times per second can't help flight time.

(Unless I'm missing something, which is very likely.)
Jul 25, 2020, 10:36 AM
Registered User
Now.... How about an 800 ?
Jul 25, 2020, 03:38 PM
Registered User
Cesco's Avatar
Quote:
Originally Posted by c/f
I doubt the sum of mechanical weights penalty, "all inclusive" whether geared or direct would be different all
Wrong

Those types of motor have linear torque over the whole rpm band. We know "power = rpm x torque", means power rises wit rpm.
A small high rpm motor has same power as a big heavy low rpm motor. Thats why rc helis are geared.

Same applies to gas motors. Torque figures are nonsense as long as you know how to use a gearbox. Only few people understand this.
Last edited by Cesco; Jul 25, 2020 at 03:52 PM.
Jul 25, 2020, 04:02 PM
Registered User
Cesco's Avatar
Quote:
Originally Posted by Steve_
fighting the momentum "x" times per second can't help flight time.
If he doesent actively brake the rotor this should not be too bad. ESC's with "damped light" can brake.

More disturbing is that the individual blade will change pitch with the power applied. This will result in unbalanced rotors during climb or descent. One blade will ride higher than the other -> vibrations.
Jul 26, 2020, 02:52 AM
Software always has bugs
There are a few posts on YouTube about the swashplateless here and here.

Great to see its application on helicopter.
Jul 29, 2020, 08:21 AM
Is what I'm doing helping?
Steve_'s Avatar
Quote:
Originally Posted by Cesco
If he doesent actively brake the rotor this should not be too bad. ESC's with "damped light" can brake.

True, I didn't think about dynamic braking. My narrow mind was thinking in reverse. Literally.

But assuming you harvest the most of the electrical energy generated during braking (an optimal scenario) I don't see how
you would come out ahead compared to traditional designs.

I'm not an engineer, but I worked with one once.

https://www.youtube.com/watch?v=8dOHEw8izno
Last edited by Steve_; Jul 29, 2020 at 09:31 AM.
Jul 29, 2020, 08:31 AM
Is what I'm doing helping?
Steve_'s Avatar
Quote:
Originally Posted by MTDV
There are a few posts on YouTube about the swashplateless here and here.

Great to see its application on helicopter.
In the first video, look at the vibration at 1:14 https://youtu.be/aEPf0QHVuMM?t=74

No camera for you.

It might be something as simple as using ball bearings to support the blade grips, instead of a pin on plastic.
It's something new and these folks deserve massive credit for even messing around with it.
Last edited by Steve_; Jul 29, 2020 at 09:48 AM.
Jul 29, 2020, 08:48 AM
Is what I'm doing helping?
Steve_'s Avatar
Quote:
Originally Posted by Cesco
IMore disturbing is that the individual blade will change pitch with the power applied. This will result in unbalanced rotors during climb or descent. One blade will ride higher than the other -> vibrations.
I was thinking CP blades have constantly changing loads/pitch, independent from the load/pitch of any other blade.

Lost in translation.
Last edited by Steve_; Jul 29, 2020 at 09:36 AM.


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