The arm and bracket are recreations of the PSU Open-X Re-design in openscad. The original re-design changed the angle from the horizontal that the arm holds the bearings from 30 to 45. I've made that a parameter that defaults to 45. If you change it, you'll want to change the height and shoulder parameters to adjust the position at which the bearing is held also.With non-default parameters, you can generate the bracket as it was in the re-design, but it defaults to produce my changes:The carriage is an edit of the Open-X Carriage mk2. With non-default parameters you can generate the mk2 or the original open-x carriage, but with defaults, you get my changes to the mk2:An additional module is provided that renders the assembled parts along with x bars and bearings. This can be useful for visualizing the effects of your edits.Instructions for changing parameters are included in comments at the top of the openx.scad file.RP PartsNuts and Bolts, Standard PartsAssembly is similar to the original Open-X except that there are two brackets instead of one. Refer to http://reprap.org/wiki/OpenX.