Purse I3, X Axis ends - For Thread Rod w/backlash nuts

A friend was looking at using these for a Prusa I3 build and did not want to use the precision threaded rod and wanted to stick with all thread like in so many other printers. Instead of printing the nut adapters that replace the brass precision nuts I merged the two designs together so the nut pattern is incorporated in the final printed part. The nut pattern is for a 5mm rod and nut.

7-31-2016 - Added an 8mm rod and nut version. It does cut into the side of original part do to the siz