Hope this is in the right section and not out of line.

To the builders out there great and small.
These sounds like a juvenile questions but, rotaries are a different world.

1. Do you fabricate your own cams?
2. Are there sources for cams besides going through the few suppliers that offer them?
3. Is the stroke length governed by the pin offset from center on the cam in mm?

Trying to gain some working knowledge of these and might hack the shop owners knock-offs. lol