I believe I received a defective motor from 3DR.
I ordered the Quad kit, full electronics, with the 850kv motors.
When I apply throttle, all of the motors start up (no props!), but one of the motors sounds like it is "sputtering". Within 10 seconds or so, that motor cuts out. If I return the throttle back to zero and try again, the bad motor will restart, but it quickly cuts out again.
Things I have tried with no improvement:
* swapped ESCs
* swapped the order of the 3 motor wires
* hooked the ESC directly to receiver channel 3
Anything else to try? Otherwise I'd like to know how to get a replacement.
Tried help@3drobotics. So far crickets.
I have had some spotty motor performance, too... and with so many ESCs and motors, it is not easy to diagnose - especially post-failure (crashing with a quad is unfortunately how I've learned I have a cooked motor/ESC).
Fortunately, the motors are only eighteen bucks. I'm moving to the 880kv's and still they're not breaking the bank at $24... so my solution for a very similar problem is to have spares. Buy spares - always - and be prepared to swap out in order to isolate the issues.
Hope this helps..
I finally got ahold of 3DR support and shipped my defective motor back to them. I should have a replacement next week.