Quote Originally Posted by dazp1976 View Post
+1...

You have a machine that's running so why not make some custom parts and beef it up!?.
Make some bearing carriers that are 1 inch thick to house 2 AC bearings back to back to replace those BK things.
I did that on my mill using 7201-2rs (1605 ballscrews). I'll never go back to niether standard or thrust types ever again!.
That seems to be the general consensus from comments. I didnt know the ballscrew bearings/units were a weak area but I do now. I could just get better quality bearings and swap out the generic ones. Take your point about custom bearing housings espec to support a pulley/belt system as the z axis driver.