Servers by jDrones

Knocking sound on some motors when bending propellers

(MickeM) #1


Have 6 Tiger Motors (MN4014) on a hexacopter.
This is when they are off.
When lifting one propeller tip, the motor gives a little knock-sound, on some motors.
Motors have been used over 20h.
Is it the bearings?
Is it normal? Is there a little play?
Something to worry about?
I know Tiger Motors should have their bearings changed after how many hours it was… 50-60?
How do I know a bearing is getting bad?
Hot motor? Any special sound when using them?


(Mike Boland) #2

What you are testing is bearing wear.
It happens with all but the most specialised bearings.
Is it excessive?
Depends on the amount of movement.
If you ‘just’ feel it, that is usual, and found in all motors, to varying degrees, after hours of use.
If the bell of the motor starts to have a visible ‘rocking’ motion then it is probably time to replace the bearing with good quality ones.
20 hours isn’t that much use.
Have the props struck anything in use?
Has it been transported roughly?
Have you been near the sea or salt water?
These things can affect bearings.