How big of a stepper for HF 33686 mill

[heathmanc]

I have a harbor freight 33686 mill that I am in the process of converting. I have a 3 axis hobby cnc driver and 3 steppers from kelinginc.net. The steppers are rated at 304 oz/in unipolar, 425 bi-polar. My power supply is 28V@18 Amps. My ballscrews are all 5mm pitch. Are these steppers going to be strong enough? Do I need to spring for a bi-polar controller? I don't plan on milling anything more than aluminum/brass.



Link to stepper specs
http://www.kelinginc.net/KL23H286-20-08B.pdf

Link to mill specs
http://www.harborfreight.com/cpi/cta...emnumber=33686

[pminmo]

It depends on what you want to do and how fast. Your steppers should be strong enough for your cuts. You may not get the rapids you want. If you take your supply voltage to 40V you will get better rapids.

[kreutz]

I used the same motor on my tests, look at the results here:

http://www.youtube.com/results?searc...=mardus+kreutz