"Matty F" wrote in message
oups.com...
On Mar 1, 8:33 am, "visionset" wrote:
"Sam Farrell" wrote in message

...

Sounds like an open circuit armature winding, you need a Mulitmeter
across it and turn it slowly by hand checking there is continuity
reading
between the brushes for each segment of the commutator.

Thanks Sam,
I attached my mulit meter ;-) to both brush holders and turned motor
(armature) very slowly.
Readings were between 1.5 and 4.5ohms - no open circuits.

Clip an analogue multimeter to the brush holders and measure the
voltage when it's running, taking due care to not electrocute
yourself.
I doubt that a digital meter will show a fast variation like that.

Okay I'll have to try it with my digital - it's all I have. But the stop
start problem is ~1 second cycle so should be able to observe a change in
reading.

If the voltage goes up and down then the problem must be in the wiring
to the brush holders.

Can you explain why the conclusion - my electronics is a very rusty.

--
Mike W