I'm working on converting my G0704 over to CNC like many others and have a question on the stepper sizing.
I purchased Hoss's plans and have a few questions.
The 570 oz/in steppers recommended for x and y fall off to only .5Nm at 600 rpm or so and with a 5mm lead that is at around 120 inches per minute travel.
I see people showing travel speeds of near 200 ipm where this motor has a torque of around .4Nm.
It seems that the 425 oz/in steppers would be better sized for the unit with a torque at 120 ipm of 1.2Nm and .5Nm at 200 ipm.
The sacrifice would be start up torque going from 3.1Nm to 2.2Nm.
The force developed on the lead screw is about 750 lbf at 100 rpm rating for the 425oz/in motor.
I've read lots of threads on stepper sizing.... bigger is better, bigger isn't always better etc.
Has anyone tried both steppers and have some real world info?
I'm looking at using the 16mm ball screws for X, Y, and Z with a custom double nut setup.
Thanks for the help.