Blackened washing machine commutator

[Archibald Tarquin Blenkinsopp]

If you have replaced the brushes previously did you use like for like.

I never suspected that brushes were anything special, but they are made to a tight spec in a lot of cases, and although the end purpose is the same i.e taking current to copper, there are significant differences in binders/ fillers used. I assume it's dependent on rotational speed, current and insulating material.

I noticed that with my last washer, the brushes went, I replaced them and a few weeks later the pump went.

Coincidence, or is manufacturing quality so good it can hit the expected lifespan with accuracy on multiple components?

AB

[Dan S. MacAbre]

The washing machine packed in this morning. Filled up with water, and then nothing. I expected I was going to need to replace the motor brushes (although they're only about two years old), but they are still quite long. I noticed that the commutator lands (or whatever you call them) were blackened, and that the face of one of the brushes was quite rough, like anthracite. I also remembered that last night, it was making what I now realised was an arcing noise, and not a chattering noise that I'd normally associate with the brushes getting too short. Anyway, I cleaned them up, and it's working fine now, but I'm wondering what caused it. Is one of the brushes malformed? Or has low spring pressure? Or something else?

[Archibald Tarquin Blenkinsopp]

Assuming the brushes were identical, can the suppression caps be changed or swopped?

If you can fire up the motor while watching the aramature/ commutator it might save a bit of work dismantling the thing a second time.

It probably is the brush, but if it's fairly easy to swop the caps to see if the arcing follows the cap change, then it eliminates the only other possibility.

AB

[Dan S. MacAbre]

I bought brushes that were supposed to be the correct replacement for the model (i.e. they were ostensibly identical to the old ones); but I realise that there is always going to be 'good' and 'bad' stuff out there, and that one pretty much takes one's chance when buying things online. I've never seen one with such a burnt appearance before, though. Even when worn right down, all the old brushes I've seen in the past have a shiny surface.

[Clive Arthur]

I remember the dynamo on my old MZ Trophy used to get through brushes. The reason was that the commutator copper had worn down leaving mica insulation a little proud between the segments, and this is what was eroding the brushes. Disassembly followed by raking the insulation with an old hacksaw blade, then polishing fixed it.

Cheers

[Johnny B Good]

====snip====

Probably not but I admire your cynicism. :-)

[alan_m]

In my experience, worn washing machine motor brushes do appear to be quite long UNTIL you compare them to new brushes!

When I had a Hotpoint that went through a set of brushes every couple to three years I initially mistakenly assumed that the brushes were not that worn when the motor first became intermittent. Removing, inspecting and replacing the same always seemed to get the machine working again for a month. In the end I always had a spare set and on the first sign of a problem I immediately replaced the brushes.