Originally Posted by anlucas
I am stumped!
Just spent 1 hour trying to fit a new CP - 2800kv to this fan.
The motor seems to be balance OK - just OK. There's some vibration in the mid-rpm range. Tried 3 different 4m shaft adapters (stock, Hayoe and ExtremeRC) but I could not get anything close to an acceptable fit. There's significant vibration with the shaft adapter attached.
Just a follow-on from this post...
In the end it seems that the motor must have an issue. I wasn't totally happy with the result and I disassembled everything.
I run the motor, on 5s, without any load and it's smooth running up to a certain rpm. Afterwards, it starts screaming and I see sparks coming off the middle bearing area (the motor has 3 since it has a standoff).
I didn't notice this in the begining since I was balancing it on 4S.
This is supposed to be 6s(5 blade load) capable motor.