Hi NT
Thanks for the comments so far

On 13 May 2006 08:21:49 -0700, wrote:

Adrian Brentnall wrote:
Hi All

Until last week I was using a little (probably 1/3hp) electric motor
to power a combination diamond saw / grinder / polisher unit. I guess
that the original motor was ex an old washing machine.

Anyway - last week, said motor gave a gasp and died. Now all it will
do is buzz weakly - and won't turn - mains lights in the workshop dim
while it's buzzing (not a good sign, I think).

So - bright idea time !
Saw something on the web about using a cheapie bench grinder as a
motor - found one in Homebase, and lo & behold the pulley fitted in
place of the grinding wheel. Result !

Sadly not - the new little motor is perfectly happy to spin its own
grinding wheels - but refuses to start when faced with the effort of
spinning the combination unit - it now sits and buzzes weakly.....
darn !

The new thing's rated at 150Watts - which is probably a bit on the
light side - but any idea why it'll happily spin up its own wheels but
not my combo unit....?

Alternatively - what's the chance or fixing the old motor - no magic
smoke escaped - so I'm hopeful.... g

Some motors deliver little torque during starting, some produce lots.
So not all motors are suited to all loads.

So it seems.
I even thought I'd get smart (always a mistake!)
Tried fitting the pulley to my older bench grinder - it's rated at
300W rather than the 150W that the new ones have.

Still no joy - it just won't start under load..


Total rank bodge time:

1. wrap string 10 times round the driveshaft, ensuring that each layer
is firmly on top of previous layers so the string grips. Pull string
medium-hard at same time as throwing the switch. Very crude but
effective.

Didn't actually try with the string - but spinning the grinding wheels
by hand didn't do it - it refused to pick up..


2. If a washing machine motor has a shorted winding, running it in
series with another load will get it going. Now and then you'll find it
wont self start unless turned, if it stopped on the dead spot.
Unfortunately this bodge cant be used in a washing machine, as the
motor must start many times per wash cycle without manual assistance.


NT

I don't really want to have to 'kick-start' this one either g

Some photos at http://www.inspired-glass.co.uk/electric-motor.htm
if you have a moment... I'm wondering... looks as if it might have a
starter capacitor - but I can't see it at the moment - guessing that
it might be mounted beneath the paxolin panel with the mains
connections on...

Guessing further - looks as if I need to undo the long bolts that hold
the two end castings on to get inside - does that sound about right to
you ??

Despite having played and worked around electric & electronics all my
life I've never really got up close & personal with the innards of one
of these before - and don't want to withdraw the two long bolts just
for it all to go 'ping' and bits fly everywhere......

Thanks in advance
Adrian
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