[Ursine]

Due to the limited motion of the Z axis, I was thinking UHMW flanged bearings. Seems the alum angle and skate bearings would be overkill. I'd love to hear from anyone having experience with them.
Thanks,

Dave

[WP1]

Bad idea.

Travel may be limited on the Z, but in many cases the Z axis gets a very heavy workout. Engraving text or photos, and PCB drilling are two good examples.

Pete C.

[Ninjak2k]

Victorbl is using these for his whole machine. http://www.cnczone.com/forums/showthread.php?t=7614 He started with oilite bushings if I remember right and then switched to those and they were much better.

Why do you feel they would be a bad idea? I don't have the materials and dynamics background to do any calculations about it and any insight is appreciated.

~Dan

[WP1]

It's not so much that UHMW bushings can't work, it more that the assumption that the Z axis does less work than the X and Y is incorrect.

Many operations such as the engraving and PCB drilling noted put very high demands on the Z axis. In fact since the Z generally has a much smaller travel than the X and Y any given point in the Z slide is likely to see higher wear than a point on the X or Y axis.

Pete C.