wrote in message
...
I'm thinking of getting an aftermarket variable speed thing for an
older bosch 3 1/4 horse router [1611]. do they work well? do they go
from zero? do you guess the rpm by sound? I'm doing this so i can
safely run panel bits in a table. any info will help...thanks.

Don't want a resistive, rather a "chopper." It'll slow a universal motor
down all right, and you could get a tach setup off of the number of
commutator bars and a brush. But why bother?