Thanks Gents. I had posted my original thread over in the K2 sub forum in hopes of finding someone somewhere that could help. I have had a few replies over there. But still not clear on next steps. This evening I pulled the ball screw. As I rotated the bearing around the screw, it was really rough. Some places on the screw seemed to be okay but others felt like there was sand mixed with the bearings. I don't know how much resistance there can be before the motor will miss steps, but a few points required a really good grip and some force to rotate the bearing around the screw. The bearing at the head of the shaft also does not work too smoothly but it isn't as rough. I rotated the bearing off the screw and checked the screw shaft on a flat surface. It rolled true. I also gave the screw a good wipe down, and I couldn't see any damage to the screw. Do the ball bearings wear out after awhile? My machine doesn't get used a lot, and I can't imagine I have worn out the bearing as I do keep them lubed, but they clearly aren't working as smoothly as I would have thought they should.
I don't know how big a deal it would be to clean and repack the bearings or whether I should simply get a couple of new bearings or as you noted Jon, get a new screw and better bearings. What would you recommend?
I am attaching links to a few pictures that show my issue. The first picture is of an oak chair bottom. The ball mill dropped deeper a couple of times. One is clearly visible in the image. I ran one another chair of maple, and got three or four areas where the ball mill dropped a bit deeper. I played around with my code prior to running the last chair bottom of walnut. I cut the X,Y, and Z feed speeds by half. I also went into Mach3 and changed the acceleration and deacceleration to spin up and down more slowly and also increase reduced the steps/IPM by just a touch. I believe this is whay SignTorch referred to, When I ran the program on the walnut chair bottom the mill stopped in the position shown in the picture. I changed my program to run the planar passes parallel to the Y rather than the X, and slowed down the acceleration even more. This time I got an area where the cutter actually didn't drop low enough for about a dozen or so passes, It then decided to cut deeper and eventually stalled again. I was thinking the skipped steps were due to rapid movements. But I wonder if the sudden rapid movement actually caused less missed steps and the quick movements were better able to move the rough bearing around the screw. I got all sorts of missed steps when I really slowed things down and reduced the acceleration. I really wish I new what I were doing
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