Dead Sherline motor?

Here's what my Sherline motor looks like inside now. Today a fuse popped, when I was going to mill a piece of hardwood for a project. I fixed the fuse, and was going to carry on, when the motor started making a dragging rattling noice, and produced smoke,

Can this be fixed?

Possibly. Def needs new brushes and the comm cutting back. Depends where the smoke came from...

The easiest and probably only realistic way to fix that is with a new motor!

If you were lucky and the windings are not damaged, it might be possible to skim the commutator and clean out the gaps between segments, it may be that the arcing has caused the plastic holding the segments to change its properties and become conductive.

Ian P

Impossible to put smoke back in, commutator has been damaged, have the brushes worn too short or stuck in holder? Look very carefully at armature windings for any discolouration from overheating. A faulty winding will tend to cause excessive arcing around the commutator, this is usually game over for the armature. If the field has survived then if available a new armature may be all that it required otherwise it's new motor time.

Mike

I have no idea what happend inside this motor, but particuarly one side of the commutator is scored and pitted. The brushes looks fine actually, and they are long with plenty of life left in them. Maybe some dirt got into the motor!?

Thanks for replies so far!

Perhaps one of the comm segments came away causing the brushes to bounce and cause the arcing and eventual failure due to heat generated.
Looks like it's scrap to me, at least risky to spend a lot of money for a new comm to then find the wound fields are damaged.

Emgee

Looks like a burnt out winding to me , means a replacement armature if everything else is ok but a replacement motor would be best. Colin

Sorry to be the bearer of bad news. The commutator is well and truly dekcoof and when the motor stops in a mess like yours there is not normally electric smoke, just a spluttering halt. When in a mess like that with smoke it is normally a shorted armature winding. The field windings are probably ok but nowadays the cost of an armature (if you can source one) is not much short of a new motor so in my previous capacity of washing machine fixer, I would recommend a new motor.