Boxford TCL , Spindle motor problem

[John11668]

Just a follow -up

Used the lamp in parallel with the load and it was flckering up an down,
Took motor belt off and not much better .
Tried with only lamp connected and it was steady (able to turn lamp up and down) so sounds like drive is OK.
Bypassed the choke and tried briefly with just the drive and motor and we are back to flickering so pointing to motor.
It seems the Drive regulates motor using armature voltage feedback so may well be that a surging motor sends all kinds of rubbish back to the drive .

Took motor off and found a worn brush, andd one which had a loose connection.
Switch brushes , tweaked brush springs , and ensured brush connections were tight and all seems much improved .
Proof of the pudding tomorrow when I try some screw cutting and parting off.

Thanks for the pointers Doddy
Will PM shortly