I am taking classes to learn the mastercam software and thought I would share the process..........very challenging but I really enjoy the process.
Here is what I have so far........basically I am reverse engineering. This is an HD/Buell sprocket 46 tooth.
Using the very top circle on the Y axis I created two points and drew a tangent line to each point, I then copied this to all 46 teeth, after that I add the top portion of the sprocket to 1 tooth and copied it the remaining 45 teeth.
Almost finished
Blown up for the detail
.250 thick
Here is what I modeled my drawing off of
