I had to reverse engineer it. I took an old bent sprocket and replicated the teeth, centre hole, sprocket bolt positions, and overall size and structure. I then added in my own design.

 Nice work! The teeth conform to the ANSI roller chain standard 40. Now that you have it figured out, doesn't particularly matter. I guess this is just for other DIYers reading this comment.

 Thanks! Hopefully I will be able to make a few more and get some riders such as yourself to test them out. Thanks for letting me know what standard it was, I wasn't 100% sure so I figured I would just model my previous sprocket to make sure it would work.

 Glad you like it! It took a lot of work to make but it was all worth it in the end. I have the tool paths done so I might make another one to sell off, Chrome might be a little hard to pull off though.

 hey , if you can make a chrome one id buy it. it looks sick! congratz man.

 Thanks, I'm really happy with the final outcome, I can make one polished alu but most likely not chrome, I will look into it though. Now I just need to convince my tech teacher to let me use the CNC machine again

 haha polished alu would work. looks almost the same as chrome. and if your teacher lets you use the machine you should try to make something new instead of a sprocket make a seat clamp, or a post or even a stem maybe?

 Alright. The nice thing about making a sprocket is that I can just do an Auto Cad drawing of my design then bring it into mastercam and cnc it. Its relatively simple because everything is 2D, as soon as I bring in that 3rd dimension everything gets complicated, I would have to draw it up on a 3D software like Solid Works or a Program for Pro E which would take a lot of time and a really expensive CNC machine to run... I think I will stick with sprockets for now but I might try to make some bar ends with a plastic printer.

 Thanks man! I am really happy with how it turned out.