[EricH]

Rob, he's looking at an elevator lift's construction, not motion. (If motion is what's being considered, it's hard to beat FP motors with stock gearboxes running a cable system via winch.)

I'd look at 80-20 and their sliders--or, better, 80-20 and 357's sliders from 2007 (see the Behind the Design book from that year). It's worth a look.

Then there's the C-channel and roller system. Take a C-channel, put a roller in one end (roller type is up to you, but a Delrin block might work). Make 3 more, set them up in pairs so both rollers in a pair are inside C-channel and the rollers are at opposite ends, then link the outside C-channels to each other and the inside C-channels to each other. Need an extra stage? Make 4 more channels, but weld the extra four back-to-back in pairs. (330's favorite lift method from 1999 to 2004.)