Prusa rail kit
by Simonious, published
This kit allows the use of a rail for the Y-axis on a Prusa.
Further development of this project will be at http://www.thingiverse.com/thing:34691
Print (2 of the clamps if you are doing individual prints, the 1st STL is a full set, the following are individual parts)
You'll need 10 m3s 10 to 16mm ea (4 for the motor, two for each clamp and two for the belt tie down)
2 m3 nuts
m3 washers as you wish.
One m5 20mm+ and washers for the idler
two 605zz bearings for the idler.
A Rail with carriage http://store.trinitylabs.com/linear-rail-and-car-for-y-axis/
If you decide to go with 608zz bearings for your idler instead, you'll want to bore the idler mount hole out a bit either before or after printing.