These are monolithic (single piece) Y ends that I created for prusa i3. I was inspired to try this by the Lulzbot TAZ design, and I think it's pretty neat.
*Hey everybody , I've redone both designs now in OpenSCAD to be parametric. Enjoy! The -default STL files were generated for M8 smooth rods and M10 threaded rods. If you want to roll your own, you'll need the small parts (sub assembly STLs) which are included into the single-piece models and are not meant to be printed on their own.*
By replacing the four corner pieces plus motor and original idler mounts for the Y axis (6 printed parts) with these single-piece models, it completely eliminates the shorter M8 rods (four of them) and nuts and bolts (22 of each). Besides the elimination of vitamins, this makes the printer easier to put together at the cost of a little more plastic (both parts are approximately 100 cubic centimeters volume). The elevation and spacing of the M10 threaded rods and the M8 smooth rods has been duplicated, and the motor and idler mounts are centered to guide the belt down the middle of the frame, so these should be drop-in compatible with single-sheet frames like sgraber's. All four corners sport contoured tie-wrap guides for holding down smooth rods.
On the Motor end, a third mount was added for the stepper motor, along with a little foot for it to rest on (because stepper motors get tired). There is also a receiver slot for a 40mm fan (10mm thick). I've also added a tool-less endstop holder, which should strike the edge of the table (beneath the heated bed). It was designed to fit a 20mm x 10mm micro end stop (you'll want one that has a long throw lever).
For the idler end, I wanted to keep the tensioner capability in Prusa's design so instead of fixing the idler bearings to the end piece, I created mounts that will accept the present X tensioner (yes, X). The mounts were translated a little farther back (away from the bed) so that the longer tensioner could be used, maintaining the ability to substitute different tensioners for whatever type of idler bearings you want to use. And by reusing the X tensioner, it eliminates a model from the standard build (you just make two identical X tensioners).
If you are using a laser-cut wooden frame, you'll want to attach the motor end to the rear braces of the frame (the 8mm threaded rods were previously used for this). Pick the 277mm or 235mm sized brace depending on the width (inside dimension) of your LC frame supports. The sgraber frame that I have fits the 277mm version. The braces should be put against the inside face of the motor end, between the threaded nut and the end itself. An M3 bolt and nut can be used to secure the other end of the brace to the frame itself.