You weren't kidding about the stator variations. Most of the stators I've seen, either have magnets too large (greater than my 28mm), wrong bearing sizes (mine is a 6202-2RS), wrong stator diameter (my stator is 198mm), or even an incompatible bike frame dropout (my dropout is 150mm). I tried to simplify the process by looking at replacement motors. Still having trouble finding a suitable motor. I'm interested in a 1500w-2000w, 12 inch rim that will fit a 150mm dropout bike (e-scooter) frame. I found a QS motor....but as it turns out, the motor wasn't compatible with my frame (it required a minimum of 200mm dropout). Thought about modifying the steel frame to accommodate a 200mm dropout, but I think the project is a little too large for me. Are you familiar with a hub motor that meets my needs?
I spoke to the representative of that e-bike kit on e-Bay (earlier post). Aside from some communication challenges, it doesn't look like they know much about the stator inside the motor. I don't think I want to buy the kit, only to find the stator doesn't fit my needs. The search for a suitable replacement stator continues....
I finally found a replacement Chinese stator. Its magnets are 3mm wider than the original, but the remaining dimensions are a match. Discovered my original stator had two different size bearings. New stator uses two identical 6202-2RS bearings. Shipping was the usual 1.5 month wait, but the price was right. Much cheaper than the $130/hr X 8 hrs I was quoted for a local company to rewind the original. The new stator ran about $152 CDN (tax and shipping incl). Added silicone to the two outer motor housing plates, to make room for the additional magnet width. I'll install the repaired motor tomorrow. Thanks for your suggestions. Cheers. Polecat.
The magnets are on the rotor (where the spokes are), not the stator.
However, the stator teeth (the thin metal layers between the windings) are usually the same width as the magnets, so I'm guessing that's what you mean, and why you need to widen the existing rotor to match?
If so, that's ok...but silicone is not sufficient to "fill the gap" by itself, as it wont' transmit stresses from rotor to axle the way the covers are designed to.
what it means is that the bolts securing the cover will do all of that load transfer, and they'll break (or unscrew and fall out, or both) from the repeated rotary bending actions, disconnecting the covers from the rotor, makign the rotor magnets roll on the actual stator laminations.
you'll need to make a solid, hard ring to fill that gap. lexan or plexiglass or a number of other things can be used, if you can't get metal rings made. the rings will need to have a recess for the lip of the covers to go into, and a lip of their own just like it to go into the rotor, to help transfer the loads into teh covers so they can transfer to the axle.
you also need rings on the axle between the cover bearings and the axle shoulder of the stator, if there is any gap there, or else the wheel can move side to side on the axle while riding, and allow the windings to strike the covers, and destroy the new stator.
Your right. I think of the stator teeth as electro magnets. I was afraid I may have to add something a little more solid between the side covers and the motor housing. I'll investigate it further. Cheers.
Testing the new stator this week. So far, no issues. Looks like housing can accommodate the extra 3mm wide stator teeth. Doesn't appear to be any interference. Did notice this stator is slower off the mark, but seems to have a higher top speed. Probably due to wire diameter size and number of windings (compared to the original). Physics...what can you do?
yeah, if it has a higher kv (rpm per volt) because it's wound differently, you can increase current limit on controller or change the controller out for mroe powerfull one to get the oomph back, may also require increasing system voltage, as long as the motor can handle the extra power without overheating.
but at least you're back on the road.
as long as the covers don't touch the windings anywhere inside, should be ok, but ive had covers that slightly touch windings and eventually rub off the isnualtion and start shorting windings together.