This is my first router build and I need help on figuring IPM for my machine. Does anyone know of a good site or spreedsheet that can figure this for me. I am planning on going with rack and pinion instead of ballscrew. Below are the specifics for my motors and gears.

Superior Electric MX111-FF401 motors
3.4 amps 4.0 Volts 750 Oz-in

Rack and gears

20 degree pressure angle gears
16 pitch 3" pitch diameter

Any help would be appreciated