G'day all.  I noted some good suggestions in MMD regarding old electric
motors but I would like to stress the importance of checking the wind-
ings for problems and the supply for correct voltage, frequency, AC or
DC, especially if there is any tendency for running hot.

Many early mains power supplies were somewhat different to those today.
Around the world, many different supplies have been used in the past;
here in Australia, 32, 110, 200, 210, 240, 250 volts, ac and dc, 40, 50
and 60 Hz was used.  In North America, the voltage has varied, including
32v dc and 25 Hz ac.  It is acceptable to use a higher frequency than
the rating but using a lower voltage can be as harmful as too high a
voltage.  Old insulation will always be suspect and any over-voltage
or temperature will likely shorten its life.

My restored 1914 upright Duo-Art was running OK except that the
motor was too hot to touch after some use.  I had used a transformer
to change 240v 50 Hz to 200v as rated on the old motor so that wasn't
the problem.  I took the motor to a specialist shop where shorted
turns was diagnosed and now after rewinding, the motor runs quite cool.
I am confident that that motor will run well for many years yet.

Cheers,

Darrell Clarke,
Adelaide, Australia