We all want percission with our machines, and some of the diehards buy the expensive percission screws and acheive their desires and look at the performance of the Tormach Mills which reportable keep good tolerances.

Big question, can you get the same results with the screw mapping functions of mach3. And what is involved to do it. Sounds like it might take attaching a DRO to actually do the mapping. Also, it looks to me that you would need to have accurate homing switches so that the machine would know exactly where it is.

I can't find any info on mapping in the mach3 manuel, but I think that this subject should be explored in order to add computerized accuracy to the .003 in 12 inch possible error in the most popular rolled ball screws.

What do you think?

Ron

Ron,
I agree, MAPPING seems like a great low cost way of addressing the rolled ball screw or lead screw accuracy issue, especially on large machines. I know that many of the ballscrew manufacturers and at least one of the lead screw manufacturer (KERK) can provide lead accuracy maps for their products. As you mentioned, mapping on an assembled machine could be done with DROs, lasers (that is how many of the machine tool and screw manufacturers do it) or perhaps even an optical centerfinder and a machinists scale. The optical/scale method would probably not be very accurate, but could be used to catch a large accumulated error over a long travel distance. If the DRO data capture and input thing could be developed for Mach 2/3 that would be useful, but not worth buying if you are just building one or two machines. I think that a low cost DRO based "calibration system" available for use on a share or rental bases would be ideal!
Regards,
Dan

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