Sizing a motor for a particular job.

[jackorocko]

I have got this bright idea to use a dc motor to control my milling bed movement. The mill already has a gearbox with reverse. The way I see it though I could buy a dc motor and have that run the gears that control the mill bed movement. I plan on using a arduino to control the motor.

I guess my biggest questions are, what size motor would I need? How much torque is required? Would a dc motor do the job or would something like a stepper motor need be required? I am looking at the L293D motor driving chip, does this cut it or would I need more power?

I don't need precise control as I am just trying to separate the mill bed movement from the spindle speed. The problem I have encountered is that I can't lower the feed speed of the bed any lower. If I can lower the feed speed of the table I can decrease the size of my cut making it cleaner and smoother.