Originally Posted by
routercnc
I'm in the process of doing just that on my new Mk4 machine on the long X axis. Because of the arrangement in the design I will not use off the shelf parts - instead I will be re-machining the floating end to have a lock nut and thread, and then use a thrust bearing between the lock nut and radial bearing to vary the axial pre-load. I'm likely to need a spacer in there to ensure force lines pass through the right part of the bearings. Hopefully when I get the video out (could be a few weeks yet) it will be clearer, and in my case it should make a neat job of it.
Alternatively, and easier if it can be done on your machine, you can use the same fixed end bearing set (that you have at the drive end) with angular contact bearings in to apply the axial pre-load, but you would need access to a lathe to machine the floating end of the ballscrew to suit. Then to apply preload to the ballscrew depends on how it is bolted to the machine. If the bolts run through the vertical holes then you just need to pull the ballscrew tight and torque up the fasteners. If the bolts run through the horizontal holes you need some way of shimming it away from the mounting face to get the axial load applied.
edit: apologies, realised I've replied to a poster, not the OP. Malcolm, create a new thread if you want more.