Thread: Discussion Japanes Ball Drone.
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Old Oct 14, 2012, 12:52 PM
corocopter is offline
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Hello Sam, and Ben,

Thank you for the kind words, I watch this thread with keen interest.

Ben, Welcome and thank you for posting your vids and details. I'm impressed with your workmanship and perseverance.

I have several suggestions or thoughts that maybe of help, but first can you tell me if your are use a single propeller or a counter rotating pair on version 13A? I was not sure from your description.

Two thoughts:

A single large diameter slow turning prop will work to increase thrust and stability.

Idea #1.

First thrust: ..... you want to slowly accelerate a very large mass of air (i.e. a large diameter slow turning single prop) as apposed to rapidly accelerate a small mass of air (smaller diameter twin fast turning props)

Idea #2

Second stability: The large diameter prop will create a great deal of gyroscopic stability that combined with the mechanical off-set of the control vanes will create a sort of localizing stability, much like can be seen when you view a full size or large glow powered helicopter viewing it from the tail end in hover. What you will notice is the fact that the helicopter will be tilted downward on the right hand side, this is due to the resultant vector forces of the tail rotor forces interacting with the main rotor torque. In the spheres you don't see this tilting since the control vanes are on opposite sides of the craft yet there is still a resultant force vector that created a stabilizing force.

I'm expecting some very astute poster like Brandano to take me to task on idea #2.......but the idea is much like standing on polished ice with leather soles, if you have counter rotating props; the lightest motion and you skid all over the place.

On the other hand a single prop with off-set vanes is like the above person but imagine the person is holding onto the handle of an old fashion kids wagon, the person will have a very slight increase in stability, not much, but just the amount that slows things down so the human sense of balance can react against the wagon handle and allow the person to move across the ice in small steps.

Please post photos of all of your versions and some details to allow us to learn from your hard work.

Many thanks,

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Last edited by corocopter; Oct 14, 2012 at 03:22 PM. Reason: spelling error
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