Have just put together the BlueROV2. Build all went well and seem to be working until I came to checking motor directions. Thruster 6 (top mounted) does not seem to respond correctly to inputs. Most of the time it does not spin at all. If I alternate directions, it will sometimes spin (but only in the one direction). When it does spin, even if the input is set to low (thruster 5 is spinning slowly), thruster 6 will spin at full throttle for appx. 0.5 secs and then stop abruptly with a screech. The motor spins fine in both directions when turning by hand, and hasn’t yet been used in the field or for long periods of time out of the water. The most worrying is if I leave the unit armed, sometimes the thruster will start spinning (which I have read is not unusual for a stationary vehicle), but it will ramp up to maximum speed, and then I am unable to disarm and have to pull the battery.
I have checked:
-mavlink shows channel 6 responding to input, but no spin
-the thruster. Disassembled and inspected; all visible parts seem fine and propellor spins freely by hand
-connections at ESC/motor terminal
-checked connections at Pixhawk
-haven’t yet plugged another thruster into channel 6 ESC/Pixhawk to test
Any ideas? Many thanks,