Re: Stepper motor vibration problems
You'll waste a lot of time and money converting to ball screws. The motor vibration is resonance from the stepper because of the poor design (moving too far per revolution). You are asking the stepper to operate outside of its optimum parameters. Using a ball screw will take you to the other extreme, not moving far enough per revolution (5mm or 10mm). Your top end speed will be slower than ideal for plasma. All commercial tables I've seen use a rack and pinion drive, you just need to add a reduction drive 3:1 or 5:1 using timing belts. It won't cost a lot nor will it take very long to make a reduction drive that has the same mounting pattern as a NEMA 23 motor and it will be sweet.
Rod Webster
www.vehiclemods.net.au