3 inch "RC" helicopter - RC Groups
Thread Tools
Dec 20, 2003, 09:54 PM
Registered User

3 inch "RC" helicopter

This is a just for fun experiment at making something very small that can fly even if only with minimal control. It is not meant to compete with the more significant efforts of others who have built truly micro RC helicopters.

The photo shows a 3 inch radio “controlled” helicopter with one channel (throttle) control. It weighs 13 grams and can only fly for about 30 seconds at this weight. It is stable when hovering or in a slight climb, but starts an orbit motion when descending. The stability is obtained by the rotation of the anti-torque vanes coupled with a proper mass distribution and the CG being located far forward. The anti-torque vanes are powerful enough to cause the body to rotate in the same direction as the propellor. You can see a video of it flying at:


The movie is stored at full resolution and is 8.3 MB.

Steve Morris
Sign up now
to remove ads between posts
Dec 20, 2003, 09:57 PM
account suspended
EricCartman's Avatar
didnt we see this concept before exept with duct
Dec 20, 2003, 10:42 PM
310mph Kolibri T25 Swist
henke's Avatar

finally a micro with picture and video! looks fun! just need a way to controll direction....

Dec 20, 2003, 11:04 PM
Registered User
awsome can you post plans and all that. bob maget
Dec 21, 2003, 01:33 AM
account suspended
EricCartman's Avatar
Dec 21, 2003, 01:33 AM
account suspended
EricCartman's Avatar
use a actuator to adjust the anti-torqe veins
Dec 21, 2003, 04:53 AM
Registered User
Steve, That is so cool. I love the hand catch. We missed you tonight. We will probably hold a meet on the 27th. You have to bring this.


Latest blog entry: Car Show
Dec 21, 2003, 03:17 PM
Registered User
jas_Qfix's Avatar
Congratulation Steve.

I was wandering whether you have tried the vanes to spin the other direction of the prop.

I have one of these UFO floater and the prop and the vanes are reverse twisted and they also rotate in different directions.

Still trying to find ways to control the directions of flights.
Dec 21, 2003, 03:51 PM
Registered User
isaac-bees's Avatar
just make your prop a little more efficient and put it in a duct. You could then use 2 small linear servo type actuators to move the battery around above the prop like the Hiller flying platform. Looks really neat. I second the finaly something that is not hush hush... I am getting a little sick of that!
Good work!
Dec 21, 2003, 04:23 PM
Registered User
Thanks for all the comments. I don't plan to make this model fully controllable because precise control requires some type of cyclic input to the vanes and since the whole thing rotates, I'd need an IR, RF, or magnetic heading detector to do this. The current design is more stable climbing than descending, so a crude form of control can be obtained by pulsing the throttle at the correct times, kind of like driving an RC car that only turns left.

In my 'real' job I've worked on several ducted hovering designs that fly autonomously. Their stability properties are not the same as this vehicle and normally the ducted vehicles fly with a full stability augmentation system.

The picture below is a prototype of such a vehicle powered by a 60 size glow engine. It weighs 9 lbs and is capable of fully autonomous flight using its on board computer (with GPS, gyros, etc..). I don't plan on trying this in the 3" size!

Steve Morris
Dec 21, 2003, 09:39 PM
account suspended
EricCartman's Avatar
aww..you're so mean!
Dec 21, 2003, 10:35 PM
Only nerd in the village
Maybe we should have this thread revived:

Dec 22, 2003, 06:11 AM
Hacker motoren rules :)
Philip Thulin's Avatar
This is just TOO AWSOME!!!

I was roling on my back laughing (well allmost ) when I saw the vid, great stuff!

Dec 22, 2003, 10:59 AM
Registered User
Here is the latest version of the 3" helicopter. The anti-torque vanes are larger and flat and the total weight has been reduced to 10.5 grams. The vehicle now rotates in the direction of torque because of the flat vanes. Flight times are around 30 seconds on a charge, with several shorter flights after the batteries recover from the high current draw. The rotation rate is much slower than version #1 and the stability is different, allowing a very crude form of position control.

Dec 22, 2003, 11:22 AM
Registered User
jas_Qfix's Avatar
This is going to ground all my other micro heli projects.

Thread Tools