About this 3D model

UPDATED. An option to replace the X carriage on Mendel RepRaps. *Variable length between bars. *Variable width for extruder mount, or other tools. *No more need for fitting things in the X carriage holes. *NO GLUE, but you can use glue instead of set screws if you like. *Hole for an LED to point down towards your print, and a channel to run the wire. *Less Plastic than anything I've seen so far. *More visibility where the extrder filament drive meets the hot end. Pictures show the finished replacement installed and lit up. I have it connected to the blue toggle switch. Also show the intermediary step of changing it out.