RC India

RC Models => Multirotors => Topic started by: atulrajguru9 on November 15, 2012, 09:28:22 PM



Title: Need help to trim my TriCopter
Post by: atulrajguru9 on November 15, 2012, 09:28:22 PM
Hi friends,

I am almost ready with my TriCopter only thing remaining is to trim it.

When i increase throttle all 3 motors do not lift from ground at same time.

I tried to use trim on my RX but that did not help.p

When i increase throttle upto 50% it takes off but tries to go here and there.

My gyro gain settings are as P = 50%, R= 50%, Y = 50%.

Here are things i have already checked.


1) props are balanced

2) ESC are calibrated before and after connecting to board

3) Gyro direction is checked

4) Motor direction is checked

5) All possible vibration are removed

I mounted FC board at CG so its difficult to check exact CG.

If i do not get any good idea then i will take out my FC board and drill hole there to hang it and check CG.

http://www.youtube.com/watch?v=9_GzyV4cfLk&feature=youtu.be

My main problem is show in following video in last 30 Sec .

Please provide your suggestion.

Thank you,
Atul


Title: Re: Re: Need help to trim my TriCopter
Post by: RcBharat on November 15, 2012, 10:43:44 PM
Try decreasing the gain a bit or Try flashing a different firmware. May be a lower version of it.

And also please ask many senior members so that they can give you the correct solution for this

Good luck


Title: Re: Need help to trim my TriCopter
Post by: sundaram on November 16, 2012, 12:29:28 AM
Please take of from smooth ground surface not tied to any thing. Friction with ground has undesirable effects and tends to tip over on same dipping side.

Always Check and ensure CG.

Please use 30-40% negative Expo on all channels except throttle. Increase gain till it is stable but with rapid oscillations, from there reduce gain little to eliminate oscillation.

you should be able to hover with all trim received at zero with respect to FC board. Do not disturb trim thereafter.

Please amplify more on what board you are using to get accurate guidance.


Title: Re: Need help to trim my TriCopter
Post by: anwar on November 16, 2012, 01:17:41 AM
Please use 30-40% negative Expo

Just to clarify.... negative or positive values for expo depends on the transmitter you are using. For example, Futaba uses negative for smoother response around center stick, while Spektrum/JR etc use positive.



Title: Re: Need help to trim my TriCopter
Post by: sundaram on November 16, 2012, 02:44:17 PM
 :iagree:


Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 16, 2012, 09:24:16 PM
Thank you guys.

Sundaram, I am trying to do something like Darmik. (check post # 35 on page 2)

http://www.rcindia.org/multirotors/quadrotor-from-bharuch/25/

In his video quad was very stable for last few sec in my case it goes round and round on yaw axes.

i am trying get perfect CG and tune gyros.

lets see if that helps.

Thank you again


Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 16, 2012, 09:39:08 PM
I am using HK green board.


Title: Re: Need help to trim my TriCopter
Post by: Dharmik on November 17, 2012, 10:12:07 AM
Hey Atul bro, which fw you have flashed? Is that kk v1.6 tri fw you have on your HK board? Please note that you might need to reverse yaw gyro gain if it tries to rotate on yaw axis. But go outside at the open field and test it there, leave it completely free and don't give much throttle. It might roam when you are close to the ground. For the 1st try you can also try small and low pitch props for more stability. I saw your video, you built it so nicely, everything looks great. I wish you all the best.


Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 17, 2012, 02:01:12 PM
Thank you Dharmik for encouraging words.

Yes its kk v1.6 .

ok. i will check gain of yaw axes.

I am making some changes to get perfect CG.

will post updates by EOD.

Thank you again.

 


Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 17, 2012, 08:17:11 PM
to get perfect CG balance i revise design.

One more advantage of this new design is battery it not handing at bottom of Tri.


 


Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 17, 2012, 08:28:11 PM
cg check


Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 17, 2012, 08:29:09 PM
New design


Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 17, 2012, 09:18:42 PM
Here comes video ...

http://www.youtube.com/watch?v=BWEeZB--KFA&feature=youtu.be

Check around 14 sec and 45 sec it seems very stable.




Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 17, 2012, 09:27:25 PM
and sorry about blocking view by poping TX in between ...


Title: Re: Need help to trim my TriCopter
Post by: RcBharat on November 17, 2012, 09:45:20 PM
Very Cool!!

Can feel it more stable when compared to the first video,waiting for a video ropes off




Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 17, 2012, 09:48:21 PM
yes sure. :)


Title: Re: Need help to trim my TriCopter
Post by: Dharmik on November 17, 2012, 10:15:59 PM
Superb.. So what was the issue bro?


Title: Re: Need help to trim my TriCopter
Post by: atulrajguru9 on November 17, 2012, 10:36:13 PM
cg +  triming.