Sizing Criteria for Torque of Stepper motor

[dscamero]

I am in the process of designing a system for the CNCification of a RF-31 mill.
How does one determine what torque is required at the ball screw for appropriate performance? I realize the torque multiplication of the belt drive system and the 0.200 inch/rev ball screw.....but I still do not see how to quantify the performance of the stepper relative to the mill.
....thanks.
David

[jeffs555]

Here is a link to a free program that will calculate the required stepper motor. You put in all the parameters for your machine(leadscrew size and type, machine weights etc), and the desired acceleration and speed, and it outputs a graph of the torque required.

http://www.parkermotion.com/scripts/..._downloads.asp
Look for "sizing and selection tools". You do have to register to download it, but registration is free.