Hello, Looking for advise from someone experienced in motor building, trying to solve and issue by not replacing the whole motor, I wamt understand what is wrong.

I changed bearings and reshimmed my motor, it is about 1 year old. When I run it on my motolyser "sensor & magnet test" and increase rpm one of the phases the timing changes drastically , it fluctuates from say 48- 26. I then changed the timing board, same result. Just looking for clarification as to what and why this is happening.

Thank you

motor shimming is incorrect. rotor too close to sensor board

or maybe to far

+2

You have to keep playing with the shimming until all 3 phases are within 1-2° of each other... I like to start with getting the rotor as close to the sensor board without touching it, then slowly add shims to back it off until I get a good reading... it can be very time consuming, but the gain in efficiency is well worth the hassle!

Another thing I recently discovered is to check your timing ring (the steel ring where the screws fasten the sensor board to the end bell)... see if the stock ring is magnetic by pressing it next to the rotor... if so then replace it with an aluminum ring to further improve efficiency so no magnetic pull is effected by the timing ring I use thread lock and will be extra careful not to over tighten the screws because those aluminum rings are very easy to strip the threads.

I will try shimming it again, I have done quite a bit and never had this issue.

It is an aluminum sensor board, ,screws too, alumin and nylon shims, ceramic bearings. I'll go through it again tonight and get back with results.