Spindle motor problems

[geoffby]

Peter,
I had thought about this, but was assured that they will run both directions. Will check the brushes in the morning and try the motor in "reverse" (in its designated direction according to the arrow on the motor). If that's the case then we will have to run 1:1 gears by the looks of it.
Regards,
GeoffB

[geoffby]

Hello All,
To update on this problem, it appears that the original thought of the "filter" board as the problem turned out not to be. It wasn't connected in any way to the spindle motor supply or control.
So it appeared to be down to the motor itself - what was actually happening to cause the problem, I've still no idea.
I removed the brushes and they were very bad - worn quite a bit (that in itself was really surprising, as I have had motors on machines that are many years old, without having brush replacements) and burned/chipped on the mating face. One brush had the connecting wire literally fall out - a little burnt on the brush end - whilst I was inspecting it.
I removed the motor - as I said earlier, a brand new unit only 12-14 op hours old - stripped, cleaned and inspected it for obvious faults - the comm was fine and cleaned up OK (and before anyone says - NO I did not use any abrasives on the comm - just the scouring side of a washing up pad - these work absolutely fine) and the motor appeared perfect.
I fitted some new brushes and rebuilt the motor.
I have re-run the motor at around 2000 rpm - in the direction that it is arrowed - for around half an hour, to gently bed in the brushes and then upped the speed, running it in both forward and reverse directions. It sounds and runs OK at the moment and has now done around an hour's operational running since.
I did check the brushes after about half an hours running and they looked OK.
Just awaiting the new gears for the unit now, so that we can run the motor in the correct direction. Clutching at straws, maybe, but it is all that we can come up with. It has been suggested that we fit a "choke" to the motor supply to smooth out the DC, which I am looking into.
I'll keep you posted on further developments.
Regards,
GeoffB