I finally put my first rig together over the weekend and I discovered that when I tensioned the belt even slightly, the motor would start emitting a high pitched metallic whining noise at high RPM.
Here are some things I have done to diagnose the problem:
- Changed from a 260 kV motor to a 190 kV motor. Both produce the whining noise.
- Tried my motor on a friend’s board, no whining noise.
- Changed the wheel and wheel pulley with a buddy’s, and the motor still produced the whine.
- Changed the length at which the motor pulley sat on the motor shaft. No noticeable reduction in noise.
- Unscrewed the motor mount screws slightly (Effectively removing all tension on the belt), and the noise immediately stopped. Bingo!
When there is no tension on the belt at all, the motor purrs nicely, even at high RPMs. The second I add any tension and screw in the motor mount screws tight, the motor start whining terribly.
It’s also worth noting that the motor pulley and the wheel pulley are very nicely aligned. I initially thought this might be the problem, but changing the alignment didn’t have any noticeable reduction in noise.
Anyone have any ideas what this might be?