I’m using Arducopter (firmware version V4.4.4) on a quadcopter with a total weight of 1250g. The setup includes Brotherhobby F2008 motors (1000KV) paired with 9.4-inch folding propellers. The drone has been autotuned and is stable in Stabilize mode, with a flight time of around 17 minutes.
However, when I switch to PositionHold mode, the drone holds its position well for a few minutes (3 to 5 minutes) but then suddenly falls. Upon analyzing the data log and messages, I noticed a “Potential Thrust Loss” in motor . I’ve double-checked all hardware connections and also tried manual tuning, but the issue persists.
Below I’ve Attached the Data Flight Log in Stabilize as well as Position Hold.
Position Hold Mode Flight Log
Stabilize Mode Flight Log
Any advice or suggestions on what might be causing this problem would be greatly appreciated.
Overweight/Underpowered.
It looks quite straight forward - the motors and props cant safely sustain the weight of the copter.
The clockwise motors 2 and 1 are forced to run at a higher level than counter-clockwise motors because there is some frame or motor-mount twist, and eventually Motor1 is hitting maximum as the battery voltage falls just to sustain flight. This leaves no headroom for stability or manoeuvring.
There’s no option but to lose altitude to maintain some level of stability.
You also dont have battery voltage monitoring set up, which would be very useful.
So unless the copter can lose some weight, you’ll need to examine which motors and props you really need. That could lead to a rework of wiring, ESCs and battery too - just mentioning that.
Use ecalc to select new motors and props, paying for a subscription costs less than a set of props.
