Mach III and Metric Ballscrews

[Marty_Escarcega]

I am in the research mode. I am going to convert a Clausing 12"x24" lathe to CNC. Among the things I am researching, I see several vendors on eBay selling metric ball screws at what seem to be a good price. (I'm torn between the rolled metric ball screws and precision ACME screws and nuts at this point) Anyway can Mach II take the 5mm leadscrew pitch and still run run in the imperial mode?

Thanks in advance
Marty

[Crevice Reamer]

Originally Posted by Marty_Escarcega I am in the research mode. I am going to convert a Clausing 12"x24" lathe to CNC. Among the things I am researching, I see several vendors on eBay selling metric ball screws at what seem to be a good price. (I'm torn between the rolled metric ball screws and precision ACME screws and nuts at this point) Anyway can Mach II take the 5mm leadscrew pitch and still run run in the imperial mode? Thanks in advance Marty

The answer is yes. You set units to inch, but steps per inch will be somewhat different than inch screws, because of metric pitch.

For example:

My SX3 uses metric ball screws. 200 * 10 * 5 TPI should be 10,000 steps per inch. But because the metric screw pitch is slightly different, SPI is more like 10,251.

CR.

[Claude Boudreau]

Reading this tread ,on same forum, might help,

Need Help!- different lead on x and y
Claude Boudreau

[Marty_Escarcega]

Originally Posted by Crevice Reamer The answer is yes. You set units to inch, but steps per inch will be somewhat different than inch screws, because of metric pitch. For example: My SX3 uses metric ball screws. 200 * 10 * 5 TPI should be 10,000 steps per inch. But because the metric screw pitch is slightly different, SPI is more like 10,251. CR.

How do you calculate that? I am looking at this setup from a dealer on eBay:
http://cgi.ebay.com/2-antibacklash-b...item3a51b09aa9

Marty

[Crevice Reamer]

Originally Posted by Marty_Escarcega How do you calculate that? I am looking at this setup from a dealer on eBay: http://cgi.ebay.com/2-antibacklash-b...item3a51b09aa9 Marty

You can either use the tedious set and try method, or Mach3 will calibrate it for you:

YouTube- Improved Mach 3 Axis Calibration

YouTube- Improved Mach 3 Axis Calibration

CR.