Shown here is a portion of my 8th version of the MultiRep. I'm not sure how well this device is panning out, but I wanted to post it for posterity. This version has a few interesting features:
Printed Linear rails and shuttles riders
Printed threaded rods
Use of dovetails for connectors
This axis would be perfect for use EXCEPT the threaded rod is too wobbly, binds a bit too much, and was difficult to align. Could I use a metal threaded rod? Of course, however I consider that a failure of design. My ultimate goal is to remove ALL non-printable parts from the design.
I'm going to start working on my 9th version now, which greatly reduces printed parts and adds stability, Feel free to cannibalize any parts you see here. You may need to change around some paths in the scad file to get it to compile.