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Help! Motor 2 spinning faster than the rest on KK 2.1.5 board

#1
Hey guys,

I am building my first quadcopter using the KK 2.1.5 board (the frame is similar to DJI F450, using 1000Kv motors, 2200Mah 11.1v battery), but the motor connected to the 2nd ESC slot on the KK board is spinning faster than the rest. i.e with like around 5%-10% throttle I am able to stop the other 3 motors using my hand but the second motor starts spinning very rapidly within a few seconds of throttle and when I try to stop it, it throws my hand away. I switched the ESC 2 with ESC 4 on the KK board and now motor 4 starts behaving like motor 2 and motor 2 becomes normal. I did all the basic calibrations, like the ACC and the throttle pass through. So, I am guessing there is something wrong with that certain pin on the KK board. Can someone help out with this?
 
#3
When I tried flying it with the props, it didn't show any signs of lift off till about 30% throttle and after that the 2 front legs would rise while the 2 back legs are still on the ground, it was like an air hockey disc that somehow is tilted at an angle and is drifting till it hits something, but the good thing (I think so) is that when I pitch it forward the whole thing goes back on the ground and when I release the stick, after a few seconds another side goes up while the opposite side just sits on the ground. However, this was me flying it indoors, so I'll try flying it outside tomorrow and see if it changes anything.
 

PsyBorg

Wake up! Time to fly!
Mentor
#4
Did you do a full throttle calibration and set channel centers and end points? the throttle calibration makes sure the motors all start at the same time as well as have the same set range of speed as they are never set to do exactly the same rpm. The centers and end points are more for any drift issues and if set properly will allow the quad to take off level or hold level once you make a correction with the sticks. Accelerometer calibration will also help with drift in the assisted modes where the FC's auto leveling is in play.
 
#5
By a "full throttle calibration" if you mean the throttle pass through calibration, then yes. I didn't do anything related to the channel centers and end points. I am a noob to this and the only things that I did are:
  1. Load the motor layout
  2. Do the ACC calibration
  3. Do the throttle pass through
  4. Set self level to always on
I just followed this guy:

Can you help me with setting up the centers and end points?
 

PsyBorg

Wake up! Time to fly!
Mentor
#6
From the little bit I was able to turn up on the KK2 ( I have zero practical knowledge or use of) you want to go into the receiver menu for the kk and use the radio trims to set all the channels to 0. Then make sure you have calibrated the accelerometers on a level surface.

From there you can go do a hover test and see if the quad drifts still. If it does seem to drift where you have to keep a steady pressure on the sticks in a certain direction you can go into self level settings and make changes there to correct the drift. Painless 360 did some good videos for the KK2 boards and I suggest you watch them as there is a lot of great information there. This particular video of his address the drift issue and how to correct it step by step. Hope this helps you out mate.

 
#7
After watching the above video and some other ones about tuning and setup, the quad is successfully taking off and flying but only at 100% throttle. If you decrease the throttle even a bit the drone rapidly descends (the props still move and can't really see a speed difference), same when taking off, the quad just stays on the ground with the props spinning (even at 90% throttle) but as soon as the throttle stick goes to 100% the quad goes up into the air.