Robbie remarked:

> A universal motor (with brushes) as typically found in
> a vacuum cleaner won't damage a lamp dimmer device.

Whoops!  The motor (with brushes) as typically found in a vacuum
motor can't be harmed, but special controllers are required for speed
control.  They are now common at hardware, etc., stores.  The older or
cheaper light dimmers were only for incandescent (meaning resistive)
bulbs.  Anything labeled motor speed control, or florescent light
dimmer will work fine.

And too-fast rewind is showing the motor is set for a lower voltage,
and needs the speed controller to last it's normal life.  The idea
offered about just bleeding the extra air is very bad for any older
motor, making it work _lots_ harder.

Will Herzog