This bicycle part is intended to be a replacement part for what's called the 'Lower Guide Plate' portion of the Truvativ X-Guide Chain Guide. The function of this part is to guide a loose chain back onto the gears should it come loose. Because of its position on the bike it is prone to failure. Unfortunately Truvativ has not made replacements widely available for this non-essential part.
Tested using Makerbot Thing-o-matic using ABS plastic.
Available on Thingiverse at: http://www.thingiverse.com/thing:121543
This design has a hole for a 2.75mm screw. However, it is also recommend that you print with some 1 or 2 shells as normal use for this bike part can be pretty stressful. This can make fitting to the screw a little challenging. Four versions of the stl file areincluded with varying hole sizes. You can also modify the HOLE_RADIUS constant in the SCAD file to your liking.
lowerguide.scad - OpenSCAD source file for those wishing to modify the design. lowerguide_3_0.stl - STL file. Ready for print with a 3.0mm hole. Recomended for printing with 1-2+ shells. lowerguide_2_9.stl - STL file. Ready for print with a 2.9mm hole. Recomended for printing with 0-1 shells. lowerguide_2_8.stl - STL file. Ready for print with a 2.8mm hole. Recomended for printing with 0 shells. lowerguide_2_75.stl - STL file. Ready for print with a 2.75mm hole. Recomended for printing with 0 shells and very precise printers.
README.md - This file
This work by Jordan Andersen licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/