Happy i3v X-Carriage

***Update 1/18/2016***
I printed this carriage in PETG at 50% infill & have been using it for over a week without any problems. last night I printed a 14 hour print of a Delta Vertex. The carriage took over 5 hours to print. I included a photo of that carriage installed.

I modified this X-carriage design this past summer. I named it a happy x-carriage because it initially had a smile carved in the back plate. That design did not seem as functional as this, but it still seems happy. This was created with openscad. I used Draftsight to create the 2d geometry & TurboCAD to generate the ledge around the edge using the railsweep command. I have been sidetracked on some other projects, so I have printed out this final version, but have printed & tested versions similar to this. Thought I would go ahead and upload this in case someone else would like to try this part. With the added holes & triangle shaped cuts on the side, I believe this will help venting heat as well as cuttin