I have a question. What does a KK board actually do? What is its purpose. Can a scratch built tricopter be built without one (and fly)?
Hey Jim,
A KK board is just one version of a multicopter controller board. There are a handful of different types of control boards out there. KK boards from my experiences are pretty solid and are seemingly very reliable. (so far at least, I have a few hundred flites on the boards that I have without one problem) I have not owned anything other than KK boards so I cannot comment from experience about any other boards.
As far as what they do, the KK board is the "brain" to a multi-rotor machine.....they handle the mixing/rpms of each of the motors. KK boards have gyros mounted right on the control board that allows the KK to sense what is level at the time of take-off and when in flite it uses the onboard gyro to "right" or correct itself. It does this by sending a signal from the gyro to the board which then processes that information and uses tail thrust vectoring and varying motor rpm's to each of the 3 motors to "re-level" itself. (a quad copter has no thrust vectoring on any of its motors and relies 100% on changes in rpm's to adjust pitch/roll/yaw etc.)
A tricopter CAN fly without a KK board. In fact, David's (from RCexplorer.se) version 1 tricopter was built using a qty of (4) HK-401 traditional heli gyros. However from what I read about that setup, they drift a little more, and have some issues with stability when descending that a tricopter flying a KK board doesnt have. (Josh B's first tricopter build was a version 1 with gyros, he could tell ya a little more about that experience.)
KK boards as most things, are continually getting better. The first KK red boards, and the second KK blue boards flew with piezo gyros. The newest KK black boards, have MEMS gyros which are supposedly WAY more stable.....with much less in flite drifting. Both my quad and my tri-copter have the new style KK black boards in them.....I have flown Josh B's tricopter a few times, which if I remember correctly has the red board (dont quote me) and the only thing I noticed about his was that you have to "lean" on the rudder a tad to track straight in forward flite. However I believe that is because all 3 of his motors turn the same direction where as my tricopters 2 front motors turn opposite of each other which cancels the torque. the advantage that Josh has, is that he can use conventional props on all of his motors, where I have to use one conventional and one pusher. The advantage mine has is that I dont have to worry about the torque causing my machine to yaw. The prop thing in my situation isnt a big deal, cause I also fly a quad which requires conventional and pusher props to fly....so I always have some spares of each.
In summary KK boards are great.....I bought the controller card with mine so I can "flash" the programming back and forth from tri to quad, to hexa or even octo copter. which is pretty cool.
Hope this helps ya. David from Sweden is the true expert, we have all learned a lot from him and from his website. he is a wealth of multi-rotor knowledge.
Cheers!
Eric
