RC India

RC Models => Multirotors => Topic started by: sbajare on July 31, 2013, 12:17:11 PM

Title: Tilt rotor copter
Post by: sbajare on July 31, 2013, 12:17:11 PM
hi,

building a tilt rotor copter from a video shown by a friend.

i Need to know if anybody has info on this.

I am using 2 x 1000kv motors, 2 x 40amp esc.
KK2.0 board

Title: Re:
Post by: rohitgupta322 on July 31, 2013, 03:09:42 PM
With this tandem deaign. There will be issues with pitch stabilisation. Also none of the control boards available have any specific stabilisation for the tiltrotor. One has to take care of the control reversal and the instability during transition.

I have been reaearching and working on such aircraft. They are extremely tricky.
Title: Re: Tilt rotor copter
Post by: sbajare on July 31, 2013, 03:51:26 PM
hi,

this is not a tandem design where rotors are in straight line of each other.

in this case the rotors are side by side.

you are right there are pitch stabilization issues.

right now i only need to get the roll stabilized. once done pitch will be manually controlled.
only concern is to get the cg balanced correctly.

have found a link to use a kk 2.1 board. need to get one

regds
Title: Re: Tilt rotor copter
Post by: sbajare on July 31, 2013, 03:53:09 PM
hi,

here is a good link for a bi copter

http://fpvlab.com/forums/showthread.php?3537-Bi-copter
Title: Re: Tilt rotor copter
Post by: rohitgupta322 on July 31, 2013, 08:34:32 PM
Sandeep Sir, I meant the tandem configuration along the roll axis. Also, the board will only work in hovering/bicopter orientation. Once, you go into airplane mode, remember that the yaw will now become roll and roll will become yaw. Also, do you want the board to stabilize in airplane mode? If so you will have to find a way to shift the gyro inputs to take care of the control reversal as I have told above. If not you will have to ensure that the gyro stops sending any input once the aircraft locks into fixed wing/airplane mode.

I have tried this configuration before and getting the roll stabilized is the easiest part. The pitch is the real issue. Even though some people have got it working they are very sensitive.

One way to get around this problem is to have the rotors tilt outwards and inwards instead of fore-aft tilt. That uses gyroscopic forces to stabilize pitch and is very effective. In the link that you have provided, notice that the first aircraft has the arms at about 45 degrees. So, now when he tilts, the rotors are also moving forward and inwards or backwards and outwards. That is the best way to stabilize pitch.
Title: Re: Tilt rotor copter
Post by: rohitgupta322 on July 31, 2013, 08:48:23 PM
This summer I worked on a tiltrotor design at IITK. I used cyclic controls and a coaxial design. I have partially completed the flight control system. The results are very encouraging. Cyclic controls give you completely authority on such aircraft.

Most important thing, place the CG such that it lies on the tilt axis. So, that when you tilt the rotors forward to transition into forward flight mode, you don't shift the cg along the fuselage. In hovering config, place the rotors right above the tilt axis(i.e above the cg) and for forward flight, design the fuse such that the tilt axis(and the cg) is positioned at the desired point(generally 1/3rd) aft of the leading edge.
Title: Re: Tilt rotor copter
Post by: sbajare on August 03, 2013, 09:19:55 AM
hi,

thanks for the input, i need to know which board to use. right now wanna try only vtol part. forward flight will be later.

regds
Title: Re: Tilt rotor copter
Post by: lastRites on August 03, 2013, 10:39:41 AM
I think the kk2 lcd board has a firmware called the "power tower" for a bi-copter.

http://www.rcgroups.com/forums/showthread.php?t=1143569&page=163#post15500111
Title: Re: Tilt rotor copter
Post by: rohitgupta322 on August 03, 2013, 12:32:02 PM
Yes kk2 board has a bicopter firmware. I remember seeing youtube videos of people successfully using it.

http://www.youtube.com/watch?v=koNSNQ5tUIg
Title: Re: Tilt rotor copter
Post by: ayushkanwar on May 28, 2015, 07:15:35 PM
from where i can buy depron/biofoam sheets of thikness 6mm in kolkata?
Title: Re: Tilt rotor copter
Post by: kshitij saa on May 28, 2015, 07:20:52 PM
You can refer to this link.
I've made such a bicopter twice .
And the configs are damn cool.
Ccan whatsapp me for any further help
(Sorry coz I'm smaller than u in experience and age but I can help)
I'd gone out of this heck and will surely help u
7385568473