Hi F16,My motor bearings squeal.....Do I worry, or wait for more noise?
First off, how can you be sure it is bearing noise? My experience: If you can actually hear a bearing make unusual noise, you'll have catastrophic failure in the near future.
The fact that the 12" motor spins longer likely has nothing to do with bearings. I assume you refer to a condition of no-load where you have equal RPM and time the coast down. This is influenced by the rotor inertia, brush friction on the comm, windage (like a fan or rotor shape), bearing lube and seal drag.So other than squeaking, the thing (Warp 9") works great, holds spinning motion for a while, but not as long as my forklift motor (12")
If the bearing itself is causing a drag to slow the rotor down in noticeably less time, that bearing would again be destined for catastrophic failure in short order.