One Propeller Not Spinning During Thrust (Fixed)

[booleansarebinary]

I got the Crazyflie 2.1+ recently, and am trying to fly it for just the second time. One of the propellers does not spin when I set roll, pitch, and yaw to 0, and increase thrust in the app. Yet it spins fine during the self-test. I have also had one flight where everything worked normally, but when it crashed, it went back to the one-propeller not spinning issue.

I've gone through all the main troubleshooting tips: checking clockwise/counterclockwise propeller installation, checking for debris or hair, making sure each propeller spins freely. One other interesting thing I noticed was that after a flight where it crashed, none of the propellers would respond when I tried to control it next. Turning the Crazyflie on and off fixed this, but the issue still persisted with the one propeller.

Any guidance or pointers in the right direction would be appreciated!

IMG_3294.mov

[ArisMorgens]

Hello @booleansarebinary!

This could be a hardware issue. Could you try swapping the non-spinning motor with a working one (e.g. M3 with M1)? This way we can find out if the problem is in the motor or in the Crazyflie PCB. If possible, also include an image of the Crazyflie from underneath.

We'll try our best to fix this problem and have your Crazyflie up in the air as soon as possible.

[booleansarebinary]

@ArisMorgens Thanks for your response!

I switched out these two motors (not-working circled in red). When I tried running it again, that same propeller in the upper left corner did not spin.

And I've added a picture of the underside.

[booleansarebinary]

Note: I realized this messes up CW/CCW orientation, so I then fixed that, switched and the same issue occurred (as in, the propeller that would now be in the position of the red circle is not spinning).

[booleansarebinary]

The drone is currently working. I updated the firmware and all four propellers started spinning during normal thrust. Thank you to @ArisMorgens for your response and Arnaud Taffanel for the suggestions!

[ataffanel]

Glad that you got it working and thanks for updating the thread with the solution!