I've been tooling around with a whole lot of scrap from other cnc / printer / laser projects searching for a way to increase the size of my printer drastically. I have a framework mostly finished of 1" 80/20 with aluminum angles and mounts all around giving around 13 inch traveling in x and y, z.. I had sufficient openrail and 20mm extrusion for the X and Y but not Z (and I figured this to be the most vulnerable to wobble), so I wanted to try the printed linear bearings for the 1" 8020 that I had extra of (http://www.thingiverse.com/thing:82248).
These bearings had an endcap for 1" 80/20, but I was planning on using 20mm extrusion and a few leftover openbuilds components for my x ray. Furthermore, I had selected this engine mount (http://www.thingiverse.com/thing:390669)
The thing I've created (the white part in the photograph), connects the linear bearings into the 20mm x axis and puts the "leadscrew" (5/16 threaded pole right now) in accordance with the engine mount. It screws onto the linear bearing with 4 M3 screws like the first endcap did.