Dear Sir:
DC servomotors are of higher quality than regular DC motors. However often regular DC motors like those used on treadmills are used. If you can get a suitable motor without encoders, you can purchase separate encoders from US Digital, mount them on the opposite end of the motor (assuming the shaft projects out), and you have what you need. Manufacturers of servomotors are (were) Electrocraft now Reliance Electric, Dynetic Systems in Minnesota and try Servo Systems Co (used or surplus) and Pittman (they make a small 2" diameter motor). I believe I M Service sells the Pittman motor with encoders on them, or is it gearboxes??
For Acme nuts and screws, try Green Bay Manufacturing, 920-793-2411 in Two Rivers, WI. Ballscrews are made by Rockford Ballscrew, BSA, Nook, and Saginaw as I recall. Rolled thread screws are more economical.
If I were making a 4 foot router, I would use rack and pinion. When I was in business making CNC plasma cutting machines, we used rack and pinion exclusively. Rack and pinion is more tolerant of dirt, has 250 IPM + speed capability, and can be readily setup as dual side drive by means of a cross shaft. You will have no "whip" problems which leadscrews experience above the critical speed. Rack with 20 degree pressure angle is preferred to 14-1/2 degree pressure angle. In fact, my test table is 32" x 36" and uses rack and pinion; I use it as a test table for the controller which I am making and for wood routing. If you Email me. I can send you pix of it.
Regards,
Jack C.  |