Unsynchronized motor speed

Hello!

I have been trying to get my ArduCopter flying for some weeks now. I have had several problems, but managed to fix most of them.

This is the major problem I have now, and I have no idea what to do:

When I try to fly my ArduCopter Quad it instantly tilts to one side, and if I dont stop throttling it will eventually flip and break a propeller. So first I thought it was bad gyro/accel calibration, but it is level and seems alright in the artificial horizon.

For the record, I have calibrated my ESCs.

When I run the motor test using setup-motors and propellers attached I can see that one of the motors 'struggles' a bit more than the others. It doesn't reach the speed the others do, and frankly it just doesen't seem to do the job.

Here is a video of the motor test (uncompressed so a bit lage):
http://speedy.sh/XCEEs/00000.MTS

Does anyone of you have any clue of what may cause this?
Is it a bad motor?

Best regards.

It’s good that you have isolated the problem to the ESC. It is probably unlikely that the APM is sending a slower signal specifically to that ESC because I am assuming when you moved the ESC to a different motor you meant that the ESC itself moved thus being controlled by a different output from the APM rather than you having left the ESC plugged into the original output and instead just moved the motors around. Correct?

If this is true then you may need to look at other configuration parameters in the ESC. I did not see if an option in the ESC parameters is available to do a factory default so you may need to find out what the setting should be for each parameter. I am thinking that parameters such as timing and low voltage protection should be verified as it is leading towards the ESC being bad. Ensure that the battery power source and signal wire are all in good shape on the ESC, no cold solder joints or bad to loose connections.

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Daryl February 15, 2013 at 5:22pm

It’s good that you have isolated the problem to the ESC. It is probably unlikely that the APM is sending a slower signal specifically to that ESC because I am assuming when you moved the ESC to a different motor you meant that the ESC itself moved thus being controlled by a different output from the APM rather than you having left the ESC plugged into the original output and instead just moved the motors around. Correct?

If this is true then you may need to look at other configuration parameters in the ESC. I did not see if an option in the ESC parameters is available to do a factory default so you may need to find out what the setting should be for each parameter. I am thinking that parameters such as timing and low voltage protection should be verified as it is leading towards the ESC being bad. Ensure that the battery power source and signal wire are all in good shape on the ESC, no cold solder joints or bad to loose connections.
T3

Richard Boyhan February 15, 2013 at 7:18am

Usually a copter flipping on take off is either wrong prop rotation or wrong prop type or wrong APM placement. Follow the wiki and make sure you are using correct props with the correct rotation and that your APM points in the right direction.
http://code.google.com/p/arducopter/wiki/APM2RC

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ArduCopter User Group

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