Can the KK controller board produce stable video?

by ycopter | June 1, 2012 | (21) Posted in Tips

The KK board can produce excellent results, but you have to work hard to get the best out of it.  You need a well built multirotor with well controlled vibration.

But the real secret is to turn the gains on all three gyros right down and use your flying skills and not the computer!

When the gyros are adjusted to just below the point of oscillation, you can get good stable results in light winds and low forward flight speed.  But once the wind gets up and the speed of the craft picks up, you will notice that the video becomes bumpy and uneven.  Turn the gains down as much as you dare and fly it!

Note: KK board firmware with higher refresh rates (such as V4.7 Quadcopter X mode) exhibit less instability at higher speeds, but fast flight is still improved when the pitch and roll gain is backed off a bit.

Tricopter
Based on the RC Explorer V2 design with ball raced yaw mechanism, NTM motors and new camera mount design. 

2200mah Turnigy 25C 11.1v (6 minute flight time)
Motors - NTM Prop Drive 28-36 750KV / 265W
18 AMP RC Timer speed controllers
HK KK V1 board V1.6 firmware
10x4.7 SF props (Genuine APC)
Turnigy 9X radio with ER9X software and FrSky module
FrSky V8FR (HV) receiver

Yaw mechanism.


GoPro mounted on a laminate of 1.5mm fibreglass board and 3mm ply bonded together with epoxy.  This is mounted to the frame with dense rubber foam sandwiched between velcro.  Finally a loop of silicone fuel tube (not shown in this picture) is wrapped around the mount and frame which applies a small amount of pressure to stableise the velcro joint.

 

- Find this article & others like it at www.FliteTest.com -

COMMENTS

stonekap on June 1, 2012
I loved this video!!
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ycopter on June 2, 2012
Thanks, I appreciate your feedback.
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ilovefpv on June 8, 2012
Great article - you give me inspiration to improve my own RCEx Tricopter..

A few questions...

1. What kind of prop (or motor) balancing are you doing with the controller board?

2. The throttle is too sensitive on my Tri. One click up and I'm rapidly ascending / one click down I'm descending. Have you found any fixes for this in firmware - or do you just make the fix on a computer TX?

3 What is the "ball raced yaw mechanism"

Thanks so much for sharing!

-Steve
http://www.ilovefpv.com
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ycopter on June 8, 2012
Thanks for the feedback. I now only use genuine APC 10 x 4.7 props. I find they are well balanced and so far have not had a failure in flight. I still balance them using a standard non-magnetic balancer, I have tried tape to add weight to the light side, but I found the tape often moved and would fall off, I now sand the back of the heavy side until balanced. Regarding the controller board, I mount it on a sandwich of velcro and dense rubber foam. Regarding throttle control, if you have a fine pitched prop and low KV motor this gives the best control. I also use a throttle curve which gives better resolution around the hover throttle position, just like adding exponential to a control surface. The "ball raced yaw" is my design and uses two miniature ball bearings 6mm internal diameter. This makes the yaw control really precise and slop free.
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ilovefpv on June 8, 2012
I'm using the GWS props David mentioned in the build log - are the APCs more substantial?

Thanks for the feedback on the throttle control. I'll have to look into something like this. Can't get the really smooth altitute control which I'm looking for..

-Steve
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ycopter on June 8, 2012
The APC props are less flexible and stronger, but the GWS should work just as well for a tricopter weighing up to 1.3kg max. I think the cause of your throttle control issue lies elsewhere. Try adding the throttle curve first, if you are still having problems then check to make sure the throttle end point is at 100% and calibrate the ESC end points individually (normally throttle at max with props removed, then turn on receiver, wait for programming beeps then close throttle). You can also try reducing the timing of the ESCs. If all of that fails then try adding more weight to the centre of gravity!
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planenuts on June 9, 2012
i can get it to hover but it keeps spinning....why?
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ycopter on June 9, 2012
It is difficult to be sure without further details, but the most likely cause is a reversed yaw gyro.
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cwozny on July 5, 2012
This is a bad-ass video!
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ycopter on July 13, 2012
Thanks
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Jake Wells on June 3, 2012
What in your opinon is the best Controller board? I'm flying the HK board. I'm not impressed especially with descending, I want to get a better board but I'm not sure what to go with. Thinking about the Ardupilot.
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ycopter on June 3, 2012
Hello Jake, in my opinion there is nothing wrong with the KK Board, but it is more difficult to get the best out of it and does require higher flying skills as it is not self-levelling etc. Instability during decent is not unusual for any flight controller, but if you are getting a serious wobble during descent then look at your motor and prop combination. I don't really know anything about the Ardupilot, but if I was to change from the KK I would go for the Openpilot Copter Control or the DJI Naza.
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Jake Wells on June 4, 2012
Right on. Thanks for the reply. I'm new to multicopters. I'm still reprogramming my brain and thumbs to fly this thing. As soon as I turn it toward myself the fun starts. Nothing like a plane for me, flying this quad is much much more challenging. I like the Naza from what I've read, I want the accelerometer... I think. I'll check out the OPCC. Thanks
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House Of Noob on June 16, 2012
Video is really well made.
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ycopter on July 13, 2012
Thanks
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colorex on June 1, 2012
Cool! I can't wait to try out FPV!
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gmango on June 13, 2012
wonderful!

you are selling it well :)
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ycopter on June 13, 2012
Thanks gmango. I have just built and test flown a big quadcopter (850mm 1.7kg without GoPro) with a HK KK V2 board and it flies just as well as the Tricopter. It looks really stable and fast, I can't wait to see the results of the GoPro video from this set-up.
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Peaches on June 2, 2012
Awesome Video. Best I've seen from a copter in a long time. Nice flying btw, and good music too
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ycopter on June 2, 2012
Thanks Peaches, its great to have your work noticed. More videos to come...
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Big Bad Gaz on June 2, 2012
Very smooth video, nice.
Im using Davids V2.5 design and gopro mount and still tweaking but no where near that smooth you have.
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ycopter on June 2, 2012
...and that's the joy of multirotor flight, you have to keep tweaking and refining to get the results you want. If you have a particular problem you can't solve send me a PM and I will do my best to help.
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Yungpharm on April 27, 2013
Awesome and informative videos. Question: doing a tricopter build, do I need to remove power lead from my other two escs? The ones going to m2 and m3 of kk2.0board. Thanks in advance
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ycopter on April 27, 2013
Thanks. No need to remove the power from speed controller 2 and 3, with the KK2. Older KK boards and some other controllers will need the red power lead disconnecting from all but one ESC.
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Can the KK controller board produce stable video?