I am about to buy a Milling Machine, I have selected which one I want however due to its lack of CNC I plan to convert it almost immediately.
It is an Eastern Mill so I was planning to replace the leadscrews for ball screws and then fit ... servo motors on each axis.
Two questions:
1) I am only looking at Servos due to our 'workshop guy' at work recomending them over steppermotors...is there a real gain?
2) Can mach3 controll Servos? If not what would be a good set of stepper motors? (I am in the UK)
Thanks,
Andy
Mach is perfectly happy with either steppers or servos, as the interface between the PC and the motor driver is the same for either.
How big is the mill? For small (table-top) machines, steppers are every bit as good as servos, and generally a bit cheaper. For large machines (knee mills) servos *may* make more sense. But, really, outside a production environment, it's more a religious question than anything else. Up to and including a Bridgeport-sized machine, you can get perfectly acceptable results with either. There are pros and cons to both, but the functional differences are generally rather minor, and often not good for much more than bragging rights (My mill will rapid faster than your mill!). By far the most important things, no matter which you use, are to size them properly, gear them properly, and power them properly. Most beginners tend to start with steppers, and grossly under-size them. Then based on the poor outcome, they decide steppers are inherently no good, and will always lose steps. This is simply not true. Mariss Freimanis, the owner of Gecko (
www.geckodrive.com) has a good rule of thumb: Up to 100W, use steppers. Above 200W, use servos. Between 100W and 200W, use either. You'll find some good information on stepper sizing, and power supply spec'ing on his site as well. Whichever you decide on, I'd strongly recommend Gecko drivers - they are first-rate, reasonably priced, and well supported.
Regards,
Ray L.