This is the openscad script for customizable prusa i3 based parts that is primarily based on Geeetech printed parts structure.
The objective here is to make the parts able to be customized. Although this isn't a pure openscad script because of the "import", but you can pick your own screw size and distance (for mounting purposes)
Also to develop a preset based parts such as screw holes for Geeetech parts or hephaestos x-carriage, vanilla based screws, greg wade's extruder and probably others