"Bob May" wrote in message
...
The motor in a Dremel is a universal motor and, as such, has no problems
at
all with the usage of a reostat or variable resistor in series with the
motor. I'll note that there are models of the Dremel that have a built in
electronic speed control and you can use that in series with the reostat
to
limit the max. speed of the Dremel.

Just what I do. Works just fine. By the way, the cheapest rheostat for
the purpose I have found is a sewing machine rheostat. Even new, their
about $10. I've bought them for a buck at junk shops.

Boris