On 2012-05-29, Steve B wrote:

"Bob La Londe" wrote in message
...

[ ... ]

I did find a foot control for a sewing machine today. Would that work?

Probably not well at all. Sewing machine motors are very low
horsepower, compared to circular saws. (Something like 1/10th vs 1 HP
or so -- more for larger blade diameters.)

And
how do I tell if it is an induction motor or a universal brush?

1) Look for insulated screw-in caps on the outside which allow you
to inspect and change the brushes. (They wear out over time.)
They should be about in line with the end of the rotor where the
commutator would be, if you know what those are.

2) If you can't find screw-in caps (probably a cheaper saw), look
in the manual (download it from the maker's site if you can't
find the one which came with it) and look at the diagram. If
you know what motor brushes look like, you should be able to
recognize them in the drawing. If you don't, spend time reading
through the parts list which accompanies the manual looking for
the word "brush" or "brushes".

I feel stupid asking that, but I'm merely ignorant, never having been told
about this before.

And you've never had a power tool quite working because the
brushes are worn out, either? If all your tools are new, maybe not. If
you get old ones, and they start acting flakey, they probably need new
brushes (very cheap repair items), and the commutator may need to be
turned and (perhaps) the mica in the grooves undercut.

But I really don't think that this will be very satisfactory
even with a speed control. If you want to cut at slow speeds, you need
to gear the speed down and the torque up -- e.g. use a motor designed to
run that kind of saw blade.

Good Luck,
DoN.

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