I use this carriage on RepRap Prusa Mendel i2.
ABS. 0.25mm layer height, 25% Infill
This model made in SketchUp Pro 2015 v.15.0.9350

Features of the Y carriage:

• easy to print
• easy to install
• compact and looks good (IMHO)

Except this model you need to print some other models:
1) LM8UU Bearing Holders http://www.thingiverse.com/thing:779911
2) Mounts for Aluminium Plate http://www.thingiverse.com/thing:779899
3) Belt clamp http://www.thingiverse.com/thing:779917
4) Belt clamp nuts holder http://www.thingiverse.com/thing:779919