[little bubba]

About 3 months ago, I notice that the tool holders were not pulled up tight against the taper, so while having the sheet metal off and looking at that a part timer, jogged the table and cought a clamp on the Z ways and blew a driver board, so now the machine is sitting for four days to get the driver board. Oh yeah, the tool holders aren't tight, clean everything, and finally figure out that its the belleville (sp?) springs and drawbar. (the previous owner seemed to think that spacers should just be dropped in the hole when a spring broke, dumbass). Anyway after 8 days of sitting we finally get everything all set and the Z axis is making a whole bunch of noise. From sitting or whatever there is a whole bunch of rust all around the bearing carrier of the Z screw. A welfare stethoscope(screwdriver) check confirms this. So now check the backlash, its fine.

Fastforward to yesterday. Running a part that uses four tools to make up a flat surface, small radiuses and whatnot. It was the worst looking thing I've ever seen, remeasured tools several times and still the surface was all over the place. Some of the finish tools weren't even cleaning up the roughing. This sucks, so I found something else to do, bring in the swamp cooler, check out E-bay for some inserts, etc.. So this morning, I ran it again,(who knows maybe the underpants gnomes fixed it). Same thing. So I set the backlash back to zero and check it. .00186" fairly consistant through the whole Z. I did find out that the controller doesn't like the number 186 for backlash compensation, it seemed to think I meant zero.

Now for the actual question, I can get a new bearing carrier for $480, but can I just change out the bearings for less. I know its going to be a matched set of thrust bearings, I've done that before on a lathe. Or is it a sealed unit. Anybody done this before, I'm not too worried about the actual mechanical part, shove a rod through the counter weights, block up the head, rip the motor off and the rest should be cake. Anybody have any tips or tricks or anything that I'm missing?