Variable CG Pitch Control (reversable plane)

[Fraser]

Hello im new to the forum, I was just listening to the podcast and they mentioned one of the challanges I posted on the facebook. Not sure the best place to post this.

The challage is to build a plane that can transition from foward to reverse flight. I do not have the resources to build anything at this time but would like to share a few of my ideas.

1. The use of an rc car speed controller and a sensored motor to give foward and reverse. Props might be a problem but I am not sure how handle that.

2. The use of a moving tray of some sort for pitch control. My thinking is you could mount the battery in some sort of tray on rails. So in effect you would be shifting the cg of the aircraft to control pitch. This would remove the need for elevators. Possibly using a servo as a worm drive or even a pulley system.

3. Possibly using drag flaps in place of a rudder to avoid the problem of changing direction.



These are the main problems I can see and can think of possible work arounds. I think the wings might be a problem aswell. Would love any input on this and ideas on how we can see this happen.

Cheers
Fraser

 

[frogman]

Along the same line is the reversible pitch prop/motors out right now. People are using these to fly 4D. They are able to move the plane in reverse. You can do a nose down hover. It's crazy cool and very impressive. Is this what you are thinking or are you thinking way more complicated and elaborate.

https://www.youtube.com/watch?v=6YkkZw9GVaU&list=UUE5VFtMfZi8wSPoYp7Vt8LQ

 

[Fraser]

Thanks for the reply


I remember that video and it is amazing, my idea was more along the lines of a plane that is fully supported by the lift generated instead of the prop. So it would be possible to fly the plane foward. Throw it into reverse and adjust the cg which could be tied together on the reciever and then fly in the reverse config, so tail toward and the plane would become a pusher instead. Assume the prop is up front.


The plane would serve no real purpose. Although I can see variable cg might have a use in racing. If you could move it foward to prevent a climb under high power without adding the drag of elevators. Not sure on this though.

Best way to think about it is like a submarines ballast tank, but flying...... I mean they are both fluids haha

 

[stay-fun]

Interesting project! How about making it simple (at least at first). How about a wing. It should have elevons on both the leading and trailing edge of the wing. Further the leading and trailing edge should be symmetrical (since leading and trailing edge are reversed when flight direction is reversed).

With one motor and prop, you have a pusher AND tractor design wing!

 

[Fraser]

Yeah that might be easier lol.

Im sure these fancy radios people have now could be set up to switch which servo they use when you reverse it.


I wonder what happens when you have control surfaces on the front of the wing. Or a rudder on the nose?


Lots of odd things could happen if someone tries this haha.
Thanks for the input so far guys

 

[SamPedro916]

Variable Pitch Prop Thrust Vector 4D rc planes

Search VPPTV (variable pitch prop, thrust vector)rc plane or 4D rc plane on YouTube and be prep aired to have your mind blown. They have already mastered this, and these guys are amazing, backwards flight, tail vertically up hover, it's the coolest thing I've seen, It's much more refined than 3D Helis, almost like ballet.

 

[stay-fun]

It's much more refined than 3D Helis, almost like ballet.

I'm just gonna prentend I didn't read that
And yes I've seen videos, it's cool, but they don't really fly circuits backwards as far as I've seen. Would it be possible?