Hi all,

Took on a foreigner out of personal interest a couple of days ago. An electric scooter wheel. Took it apart to discover that it was running on brush tails and consequently has damaged the comm and melted the brush gear/holder (is cast as one piece), however the interesting bit is the two brushes on negative supply side are pristine when the two damaged brush holders (and worn down brushes) are on the positive. Asked around to discover that it is general knowledge that this occurs now and then. I don't have an answer as to why though. The fields are fine and it's not on account of a stuck brush because it's two of them and they are worn down to tails. Any Ideas. I don't want to get too carried away until I know the cause.

Any insight appreciated.

Clayts

PS photo attached

OK.

I've viewed my own post about 10 times or more now, I'm guessing that either it's an obvious problem and I'm not worth humouring or it really is a tricky one. I'm going to take a stab at it myself. How about this. The excessive brush wear has probably come about because the neutral point has been squewiff since day dot which has created arcing since manufacture, also lending in some way directly to this uneven brush wear scenario( even though it's final demise was the ultimate wearing down of brushes altogether) OR the neutral point has been shifting itself due to excessive load ...or more simply the motor is underpowered given it's intended purpose! I prefer the latter due to it's cheep nasty design in general, such as no coil insulation whatsoever bar the slot liners and caps, no bearing registers on shaft (given that it's actually a wheel - this is a worry), thin copper segments on comm (can't even skim in fear of going through). among a raft of other engineering shortcuts in it's design. All in all a nasty piece of Chinese c**p.

Having had this little moan has made me feel a little better, however I'd still like know WHY. Any suggestions?
How far off am I?
Humour me

Clayts