Yamaha Nytro Torsion Spring Hook

Print to replace a warn out Torsion Spring Hook for a 2010 Yamaha Nytro. They were out of stock locally and I wanted to ride. Should fit other Yamahas and maybe other sleds as well. Anything with a 35mm (1 3/8 inch ish) mounting Diameter

I had a coworker print it on an X1 in PC. He did 80% infill. Lasted just over 1000km and the hooks were broke on both sides after the last ride.

Changed some clearances and printed a set of prototypes with bambu PETG-CF 25% infill on my A1 Mini. Lasted over 2000km and are still on the machine. I even broke a bogie wheel that is missing in the cover picture, and the hook held up that entire ride. I did manage to knock the grease nipple off though some how.

I use M6 grease nipples and I fill it with low temp EP2 grease. I made oring grooves, but didnt put orings in… I don’t think they are needed by the time dirt or water intrusion is an issue the hooks would probably need replacing anyways.

I printed 2 pieces originally identical and installed them one on each rail. I would recommend printing a mirrored part for the second piece and place both grease nipples to the rear. I think under compression at speed the torsion spring and snow build up will damage the nipple. Its only a theory though I may have damaged the nipple when the bogie wheel came off. 

I isn't an exact part dimension for dimension but the Yamaha part number I replaced with my model is 8ES-47446-00. 

With the milage I have on the current hooks I think I will just run the 3D printed version. Yamaha ones are cheap enough and a solid material, but I was impressed by how well the PETG-CF ones have held up in sub zero conditions in a powersprots suspension application.