Checking the Runout and Squareness of my PM-940V

[RJSakowski]

@RJSakowski Thank you for your response, it is very informative. I would definitely be interested in your white paper.

I’m going to be away from the shop for a few weeks but when I get back I am going to spend some time adjusting everything to see how accurate I can make it. I am also going to pull the gibs and inspect them carefully. I will probably put some dye on them and see if I can determine how well they fit. I do not think gibs are made very well on these machines.

I would agree regarding the gib manufacturing, Years ago, I talked with Tormach about getting a replacement gib for my x axis. They weren't normally available as a replacement part but the technician that I talked to said he could get one sent our of the factory. The gib had a slight bow to it and poor scraping to boot. Tormach uses opposing screws to adjust the gib and if tightened beyond snug, they would bow the gib so common practice was to set the gib adjustment ion the loose side. I adopted the practice of adjusting to touching, resigning myself to needing to check the adjustment periodically for drift. While their procedure uses lost motion for the adjustment, I also use horizontal and vertical table play with a check for lost motion. I developed a method for measuring drive torque for setting the thrust bearing preload which is more accurate than lost motion or by feel.

I will get the white paper to you when I get home this evening.