Why are my motors not spinning at the same time although I calibrated them?

Question

I'm currently working on a DIY project to make my own homemade Arduino based quadcopter drone. I have built the structure and have written the program. The drone consists of 1400KV motors, SimonK 30A ESC, 3S LiPo Battery and an Arduino Mega 2560. This is the first time I'm building a drone and also my first time using ESCs and motors.

Problem: The problem that I'm facing is one motor is not spinning at all until I give about 40-50% throttle and another motor starts spinning at about 15-20% throttle. The other two motors are working fine. I had calibrated the ESCs before and did it again, yet it refuses to work properly.

Previous Crashes(1): It recently occurred that when I was testing my PID program on the drone (with propellers on), it tipped over and had a minor crash due to a flaw in my program. I also noticed that I had not added an if statement that would prevent the program from giving the ESCs negative values (I'm not sure if it did give negative values to the ESCs during the crash, though the chances are it might have due to large acceleration values).

This is all the information I had to offer. If any more information is required, I would be more than happy to share it with you. It would be great if someone could help me out with getting all the motors to spin at the same time and same speed.

Answer 1

I had the same problem on my drone: When I armed only ~3 motors was spinning, but when i lifted up a throttle last motor started spin. And if i change the orientation of controller or touch the cables motors also changed who will spin. Solve of my problem was in changing the mode of flight. I had "Stabilizied" mode when this problem was. When i changed to "Acro" my motors started spin stable as armed and throttle position changes only rpm, not which motor will spin