Quad Copter Motor Problems

Over the past few years I have been using a hexacopter with apm v1.x on it. It was a kit we bought from jdrones. It works fine. I decided I wanted to build a quad from scratch. I laser cut the frame out of plywood and installed all of my electronics. The problem occurs when I try to fly my quad. I went through the initial setup, leveling the copter, rc calibration, choose the right orientation, checked my blades and motor direction and what not. After I arm the vehicle I raise the throttle a bit and all of the motors dont always spin. Sometimes its 3, sometime all of them do. It appears to be random. Originally I thought I had a bad electrical question with the brush less motors but they all test out fine when directly connected to the rc receiver. I look at the tuning for the 4 ch of output and I would assume that all of the outputs should be very close right off the bat and they are much different then I would expect. I don't think it is a firmware issue because This project started ff at the beginning of the summer and I hadn't touched it for a while and update the firmware and it happened on both firmwares. Am I missing something simple or is there a good troubleshooting guide around.

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  • Well I seem to still have some issues with the motor controllers, The good news is that it is flying. At real low throttle settings the motors don't behave properly but once you get them up to speed they seem to work beautifully, Now I need to find a way to direct some air over the motors so they don't overheat. Didn't contemplate that when I designed this thing. It fly's wonderfully for the short indoor test that I did. Cant wait to add a gopro and head outside. Now I just need to find some free time. Thanks for the help

  • I will try to calibrate the escs. I am using new motors and esc so they are not calibrated from before. I hope that it is that simple. dont remember having to do that on my last set of escs but will give it a shot

  • I used APM 1.0 with magnetometer until firmware ver 2.91 if I am not mistaken.

    You MUST do ECS calibration procedure described here :  http://code.google.com/p/arducopter/wiki/AC2_ESC 

    ESC calibration for APM 1.0 and newer

    all motors must rotate at the same rate when you throttle up.

    I did ALL AT ONCE procedure and it worked great.

  • You said you scratch built a quad. Did you use new electronics?

    It does sound like you need to calibrate the ESCs. Do as Alex Lee suggests. If not clear do a search - many have tutorials on the how to for ESC calibration.

  • It sounds like you need to reset the max/min of your esc's. Calibration, that's the word. I'm not sure if the 1. apm's can do it all at one time. The other way to do it, is basically do one at a time.

    I believe you connect the esc to channel 3 (throttle) and without props on the motor, put throttle to max and connect the battery. You'll hear some beeps, then lower the throttle to zero, you'll hear more beeps. then raise the throttle and the motor should spin.. Now it's calibrated.. Repeat 3 more times on the remaining esc's.. that should do it.

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