Derailleur hanger

thingiverse

This is a replacement derailleur hanger for a Dawes Discovery 201 bike. I think it a number 25 hanger (but not 100% sure). My rear derailleur hanger got a bit bent causing shifting problems so I had a go at designing a new one. It seems to work well. Will obviously break on impact, so worth carrying a spare. Not sure about long-term durability or safety. Use at your own risk! UPDATE and WARNING: After riding around on it a for a few months (maybe a couple of hundred miles) the hanger finally broke. Fortunately it happened within 100 yards of home! So, this is OK for temporary use, eg while waiting for the proper part to arrive, but not as a permanent replacement. Print Settings Printer: FLSUN Kossel Rafts: No Supports: Yes Resolution: 0.2 mm Infill: 80% Notes: Support is required for the flange around the frame mounting point. Post-Printing Remove support material around the flange and tap a thread for the derailleur bolt. I did this with the original bolt, aiming to keep it as perpendicular as possible. How I Designed This I scanned the original part using a flat-bed scanner and loaded it into Inkscape to manually trace around the edge. It was then exported to Openscad where I extruded it, prepared the upper cutout section, and created holes and flanges of the correct diameter.