APM 2.6 Throttle Response Problem


Am new to quadrotors and its my final year project. I have done a long research that took me 6 months to understand each individual part and how it operates.

1- Turnigy Talon Frame (Quadrotor)
2- Q-brain 4x25 A Esc (UBEC)
3- Ardupilot Mega 2.6
4- Frsky V8FR-II HV (Receiver) + DJT AF Module
5- 1100 Kv Turnigy Brushless motors
6- Turnigy 9XR (Transmitter)

The problem is when i arm the APM everything is ok. The motors do not spin so its normal at lowest throttle but, when i turn the throttle up to 20% the motors still not spin at all. When i turn the throttle up to about 20% the motors suddenly spin in very high speed about (70%). I know its high speed because in the calibration mode the speed varies constantly unlike in normal flying mode.

1- When i calibrate the motors response is great and i calibrate the ESCs through APM ( Input receiver wires ) (Output ESCs signal wires).

2- I tried changing the gains of the throttle in the parameters list. ( nothing changed ).

3- When spinning the motors through the ESCs directly they response very well the same as the calibration mode while connected to the APM.

I have been trying to solve this problem for 3 weeks now !!! :frowning: , If needed i can make a video showing the problem.

Thank you

That sounds like exactly what happens when you take off in Altitude hold mode. Double check your transmitter mode switch set up. Taking off in stabilize mode is best.