DJI F550 motor problem

[Dynamicrange]

I just finished building my new F550. Building was really fun and it's now up and running. But there is one problem that I can't solve. One of the motors (nr 4) is much harder to spin compared to the others. On low throttle you can hear it and actually see it (watching prop from above) pulsating trying to catch up the RPM loss (I guess?). When I stop the motors that motor stops really fast and the others stop at the same time a bit later (normal). With no battery connected you can also feel with your fingers it's harder to rotate as well. Clearly something with the motor housing or bearings or whatever (I'm a noob).


Any suggestions? Obviously I contacted the store I bought from so hopefully I'll get a new motor.


Video of problem: http://youtu.be/CDpuZbD3mns


Have a nice day!

 

[el gwiz]

It's easy enough and not expensive to swap the motor for a new one, you wouldn't want to risk the whole aircraft for the price of a motor. When you get the new motor strip the old one down and if you find the problem put it back together and keep it as a spare. Be careful with the brass ring and circlip on the bottom , take it apart on a big white sheet, those bits are not easy to replace. You can use bearing oil with a needle applicator to lubricate both bearings every ten flights about, prolongs the life of the motor a bit. When you remove the outer casing you have to pull really hard as the magnets are quite strong. An air duster is quite useful to get rid of little particles.

 

[Benjamin Kenobi]

I would replace the motor mate. It's cheap and easy.