Bitcraze Forums

Hello bitcraze,

We ordered a crazyflie 3 weeks ago. This one works very well. Below are the results of the "properlers test" and the power of the motors after taking off. All the engines are about 50% after taking off.




We ordered 4 new drones this week and they work much less well. The drones crash many times. We noticed that after take off, the power allocated to the M2 and M4 motors is 100% and for the M1 and M3 motors 50%. In addition to the crashes, we noticed that the drones are less stable than the first drone we bought. Moreover, while the sound of the propellers of the first drone is rather smooth, the new ones make strange noises, as if a piece was shaking.




However we have checked everything, we have mounted the first drone and the 4 others in the same way according to: https://www.bitcraze.io/documentation/t ... yflie-2-x/
All the drones have been updated. We have changed the motors, but still the same problem. Do you know where the issue could come from?

Thank you in advance for your help.

It could be that one of the motor mounts are pointing a bit to the side which would cause it to have to compensate. As a first thing I would check that all motors are pointing straight up and if not try to twist the motor mount a bit.

Thanks for your reply. To be sure we used the mounts, propellers and motors from the first drone where everything works well and put them on one of the new drones. This time no more problem, the drone doesn't crash anymore, the propellers make a nice noise and all the motors are at 50% after take off. We redid the same changes on each drone and they all work well with the motors and mounts of the first drone.

So the problem seems to come from the mounts or the motors. We changed the supports and motors of the new drones, but the problem returns, the motors are all almost 100% after taking-off. For example on the video below we can see that the takeoff looks very complicated (like heavy). On cflcient the motors are all at 90%. And we can hear like a shrill noise. If we make the drone move, it crash.
https://youtu.be/7iOzof2olQA

It seems complicated to us to calibrate the mounts because they all look correct (at least they look very similar to the working drone). Below is the crazyflie you can see in the video:

It sounds very much like it is the motors and propellers. If you can switch motors and get it to work properly that is my conclusion. Send us an email to support at bitcraze.io and we can send you some spare motors and propellers.

The only twist to this is that we have not seen this type of problem where the motors are bad before...maybe the battery has something to do with it as well. What does the battery test in the cfclient console tab say?

Hello Tobias,

Below some battery tests on 3 crazyflies:
HEALTH: Idle:3.87V sag: 0.55V (< 0.95V) [OK]
HEALTH: Idle:3.92V sag: 0.59V (< 0.95V) [OK]
HEALTH: Idle:3.89V sag: 0.58V (< 0.95V) [OK]

Batteries all looks good. Then let's test with new motors and propellers. I have replied to the email request.