16mm supported rail how many linear bearings

[irving2008]

I've been toying with the idea of using supported 16mm rail for a Z axis, but was thinking of fitting the rails back-to-back, with the rails facing outwards. The idea is similar to the angled version already shown, but would be easier to fabricate from standard parts. The Z carriage would be channel shaped, to keep the linear bearings loaded in the right direction.

I had thought about doing it the other way around, too, with the rails facing inwards and a block carriage sliding up between them. This ends up a bit wider though, so might limit travel in the Y axis.

Jeremy

The problem with the back to back is that the main forces on the z-axis would then be perpendicular to the support which isnt really going to help much. Better to mount the supports on a bit of angle or a square like so: