In article U7uQd.44706$K54.23551@edtnps84,
Ray Field wrote:
Thank you to all that replied, your comments are very helpful.
Machine is direct drive from an induction motor, will try an electronic
speed controller to see if it works first.

Unless it is a three-phase motor, it won't. VFDs do a nice job
of controlling the speed of three-phase motors. Other induction motors
(single-phase) really don't work with the variable frequency, and most
inexpensive speed controllers are for universal (AC/DC) motors, not
induction motors.

Even with a VFD on a three-phase motor, you won't have the
needed torque at very slow speeds -- and the motor may well burn up,
unless you supply an alternate fan to keep cooling air circulating
through the motor.

Materials that would be cut are aluminum up to 1/4", brass to 3/16", steel
to 1/16". Any suggestions on TPI for these metals?

Based on thickness -- you should have at least two (ideally
2-1/2) teeth in the workpiece at any one time, or you will start
stripping off teeth. For the 1/16" steel, this calls for at least 32
TPI. For 1/4" aluminum, 8 TPI or probably 10 TPI would be better.
Probably around 24 TPI for the 3/16" brass.

On scarf joints, what angle, 30 degrees (long scarf). Any suggestions on
grinding blade to that angle?

I'm not sure, as I have a blade welder. Hopefully, others will
answer this part.

Good Luck,
DoN.
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