Well I just got my new APM 2.5 and set up my new camera Quad. On the first real flight with the system at the RC field to start the tuning process the motors just stopped and down she came from ~10 ft in the air.
Here is what I have:
HK.com X-550 frame
HK.com X-550 Camera gimbal
4 = 30amp Tunigy Plush ESC
4 = 28-36 1100kv motors
11x4.7 props
3600mah 11.1v turnigy nano tech
Canon Digital Elf 10mp
My thoughts is that the ESC that is powering the avionics overheated and shut the throttle off. now my question is:
If 1 ESC overheated will it shut off power to all the motors or will it only kill the one ESC that is overheated?
here is the video of from the quad during the crash..
It suffered minor damage and if fully functional again. The landing gear/gimbal took the brunt of the damage and a little CA and Carbon fiber reinforcement and good as new.
Replies
Check your power distribution. Not all ESCs are going to fail at the same time. I believe I have the same motors as you, the only difference is I have the Blueseries 40a ESCs. These ESCs are overkill for the motors. My ESCs never overheat. I thnk you are cutting it too close with 30A, last time I tested the motors drew 22amps at full throttle. I tested with a 10.45" prop and the motor squeezed into my vice. Add the fact that the Chinese made the ESC (mine too) and 22amps makes a 30amp ESC heat up. That's why I went with the 40amp ESC. Also the NTM motors don't have the best bearings in the world. You may want to see if the motors are getting tight or if a ball bearing is failing. The added friction would cause you to draw more power from the ESC. There's posts on the net on how to replace motor bearings, once the bearings are replaced with American Ball Bearings or similar the motors are very good. A tell tale sign that it's the bearings is if the motor is hard to turn, or if it's easy to turn and when the motor is running it sounds like a intermittent "pop corn" sound.
If power is lost to the main computer, then signals stop to the esc's, and being safety conscious, they stop, and the craft falls. Use a good switching supply and put a big cap on the +/- leads.
I doubt it's software related, because if the program locked, the PWM hardware registers would have stayed as would the ppm and the motors would have just froze at the power they were at.
It happened again.
Here is the latest log. First flight was good. no issues. Second flight it flew for a bit then boom motors stopped and down it came.
2012-08-21 16-42-16.rlog