Mitsuba SM-13 brushes and commutator condition

[djsbriscoe]

Hi,
Does anyone have any knowledge of how the brushes and commutator should be on a Mitsuba SM-13 starter motor?
Should there be carbon where the brushes actually come into contact with the commutator segments? On my starter there is no carbon at all.
There is a dark ring on the end plate where it appears some material has been flung onto it.

Any thoughts or advice?

Thanks.

David.

[TeddyEE]

I have bought an antique light ring slip which comes with a brass ceiling rose through which you feed the cable. I bought a new revolving joints - the cable and the bit you put the bulb in but don't know how to wire it because the cable doesn't have an earth and the old brass rose has nowhere to earth anyway.
Can someone who knows about these things please tell me what I should do?
I'll be very grateful for your help!



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through bore slip rings

[radiograf]

Dave, the pictures show how a starter motor commutator should look. Simply put,the brushes supply current to different windings, which generates a magnetic field. This field interacts with the stationary field, (usualy magnets in the casing) causing movement, this rotates the commutator so a different set of coils are under the brushes, hence the different copper segments. If it had plain sliprings, as in a 2 stroke alternator, there would be no movement when a current is applied.
TeddyEE, can you clarify what you are trying to do?