I completed a build of a Tarot 650 Ironman and have done two short test flights. I am experiencing random motor surge/twitch which makes the aircraft unstable. In a previous build I had the same problem. Once, during a waypoint mission, the aircraft suddenly went uncontrollable and fell out of the sky, destroying the airframe.
This quad is built with the following:
APM 2.6 loaded with Arducopter V3.2.1
APM Power Module rated for up to 10S power
Spektrum AR8010T Receiver
T-Motor MN3420 motors spinning Tarot 17" propellers
40 A OPTO ESCs installed below the chassis to minimize voltage spikes due to ESC switching action
MATEK power distribution board with onboard circuitry to supply 10V to the gimbal and 5V routed to the APM output rail to supply power to the ESC circuitry
The motors run fine when running the motor test in Mission Planner as well as doing the compass/motor calibration. Yesterday, I removed the props, armed and ran the motors in my basement with no sign of twitch/surge, so I suspect the motors have to be under load, spinning the props.
Could I solve this problem by tweaking the PIDs? I fear trying to attempt an autotune flight due to the unstable characteristics of the aircraft.
I would appreciate any help I can get!