Is motor bad

[rotem]

Hello i have this motor.
And i can see the following issues:
1.the magents are scraped up and they have no coating.
2. The stator seems to be angeld(you can see on one side it has less clerance relative to the cover)
IS this motor done for ?
After opening the motor and puting it back door it barely rotats.

 

[fill]

are the bearings worn? if so replacing them may centralise the axle correctly and enable free movement?
the damage shown looks like it could be the result of very worn bearings..

 

[amberwolf]

Coudl have bad bearings with excessive slop. (just fixed a lawnmower motor with that problem by using old hubmotor beariings, earlier today)

Also, many motors are poorly machined so the covers are not truly centered. This means that whenever you take the covers off a motor, it's recommended to make a good solid mark (punch, etc) on both cover and rotor / housing at some point on the meeting edges, and different on each side of the motor so you can be sure to install them back on the correct side.

If there are wavy washers on the axle shoulders don't forget to put those back in the same spots or the stator can rub on the side covers.

Same for putting the stator back in--make sure it's back in the rotor the same direction it was (left and right not swapped); it shouldn't make a difference but on some motors it does, either because of an offset design or because of poor machining.




If the covers aren't centered but you don't know which way they went on originally, you can try rotating one cover by one screw hole on one side, screwing it dwon, then seeing if it spins by hand without rubbing. If not, take that cover off again and move it over by another screw hole. Repeat until it doesn't rub. If you can only get it to rub *less*, then find the spot it rubs least, and then do the same thing with the other side cover until it does't rub.

 

[rotem]

Coudl have bad bearings with excessive slop. (just fixed a lawnmower motor with that problem by using old hubmotor beariings, earlier today)

Also, many motors are poorly machined so the covers are not truly centered. This means that whenever you take the covers off a motor, it's recommended to make a good solid mark (punch, etc) on both cover and rotor / housing at some point on the meeting edges, and different on each side of the motor so you can be sure to install them back on the correct side.

If there are wavy washers on the axle shoulders don't forget to put those back in the same spots or the stator can rub on the side covers.

Same for putting the stator back in--make sure it's back in the rotor the same direction it was (left and right not swapped); it shouldn't make a difference but on some motors it does, either because of an offset design or because of poor machining.




If the covers aren't centered but you don't know which way they went on originally, you can try rotating one cover by one screw hole on one side, screwing it dwon, then seeing if it spins by hand without rubbing. If not, take that cover off again and move it over by another screw hole. Repeat until it doesn't rub. If you can only get it to rub *less*, then find the spot it rubs least, and then do the same thing with the other side cover until it does't ru

are the bearings worn? if so replacing them may centralise the axle correctly and enable free movement?
the damage shown looks like it could be the result of very worn bearings..

Am not sure since the side where the stator is has the gears for the bike chain and i dont have the special tools needed in order to remove them.

 

[rotem]

Coudl have bad bearings with excessive slop. (just fixed a lawnmower motor with that problem by using old hubmotor beariings, earlier today)

Also, many motors are poorly machined so the covers are not truly centered. This means that whenever you take the covers off a motor, it's recommended to make a good solid mark (punch, etc) on both cover and rotor / housing at some point on the meeting edges, and different on each side of the motor so you can be sure to install them back on the correct side.

If there are wavy washers on the axle shoulders don't forget to put those back in the same spots or the stator can rub on the side covers.

Same for putting the stator back in--make sure it's back in the rotor the same direction it was (left and right not swapped); it shouldn't make a difference but on some motors it does, either because of an offset design or because of poor machining.




If the covers aren't centered but you don't know which way they went on originally, you can try rotating one cover by one screw hole on one side, screwing it dwon, then seeing if it spins by hand without rubbing. If not, take that cover off again and move it over by another screw hole. Repeat until it doesn't rub. If you can only get it to rub *less*, then find the spot it rubs least, and then do the same thing with the other side cover until it does't rub.

Thats a good idea i will try screw by screw until it spins.
Very good response by the way i appercite the insight you provided

 

[amberwolf]

Am not sure since the side where the stator is has the gears for the bike chain and i dont have the special tools needed in order to remove them.

With the cover placed on the axle, but not against the rotor (so you're not pushing against hte magnet force), does the axle wiggle in the bearing at all, on either side of the motor? If so, there is slop in the bearings and you can replace them to fix it. There are probably numbers on the bearing side covers that tell you what they are so you can order new ones from bearing shops, Grainger, Mcmaster-carr, etc.


I forgot to mention anohter potential failure--the axle itself, if it is not bare metal, but instead is surface-plated like a Crystalyte I have here, the softer-metal plating and the copper plating underneath it could be deformed, decreasing the axle diameter slightly and allowing wiggle. In that specific motor it actually caused the cover plate screws to unscrew themselves, on boht sides of the motor, no matter what screws I used, even with loctite, locking washers, etc. I eventualy stopped using the motor for this reason. But if the plating was thick enough, and deformed enough (which you would see on the axle where the bearing sits), the rotor could impact the stator or scrape on it. The SB Cruiser : Amberwolf's 2WD Heavy Cargo Trike & Dog Carrier