I missed this... sorry. (see Miles, I do it too )kenkad said:Hello,
I have been watching this thread with quite some bit of interest. I am particularily curious about the comment by Papa 'that he plans to CNC some sprockets from 7075T6'. I have looked all over Gates website and have never seen the critical dimensioning that goes along with specifying the machining of the sprocket teeth, regardless of which tooth pattern one chooses. Where did Papa get this dimensioning? I would have assumed that this is proprietary information. If this information is available, can we get a link to this info? It certainly is not in the PDF referenced by Miles.
kenkad
I purchased Gates sprockets in the OD I needed. I got lucky, the 75t, shown below, (and the most expensive of the two), ultimately turned out to be a freebie when I complained because it had obviously been repaired. Fortunately, it was still usable and not warped. I have a 9" lathe, so whittling them down to my specs was a cake-walk. These will be duped just as soon as he finishes the G-code. I'll have the CAD profiles and the G-code, but only for 75t (to fit 110mm BCD cranks) and 28t sprockets (for im9 IGH). Please note, the 75t measures 189mm OD, about the same OD as 46t MTB chainring.