This thing is not developed further.
I recommend to take a look at the the following thing as a successor:
Because i really like the original design, but wanted to switch over to a leadscrew driven Z-Axis i remixed these parts to fit the 8mm leadscrews that are available on eBay.
The distance from the center of the Z-Rod to the center of the leadscrew is 17mm (i think Prusa original distance).
I made 2 versions of the X-End, so you can choose between mounting the motor on the front or the back side.
And overall i made the part on most of the sides 1mm smaller.
The Idler is a Remix of "Prusa i3 Hephestos by bqLabs" and is modified for a better fit into the X-End. For that you will need two 624z bearings with an M4 screw. For the tightening mechanism take a M6 Hex-Bolt.
With this idler mount you won't bend your z-rods when tightening your x-belt!!!
There are two versions . One for a screw with a very flat head and one for a screw with a 45deg head. I recommend the 45deg version. This screw won't touch the leadscrew
I didn't mount it yet, but the first testprints seem to be good and don't need further modifications. So, feel free to test it. As soon as i have mounted the parts, photos will follow.
IMPORTANT! If you have downloaded the files till 29.09.2016 then please re-download. In my old design it wasn't possible to put the 8mm rod into the mounting holes!!!