Originally Posted by project5k  .....but i had another thought, sticking with the seperate lobes idea, why not make all the circles, center drill them,...etc, etc. |
You do not need to worry about center drilling or keyways. You are coming around to the suggestion I made earlier;
"What you call the conventional cam should be simple; they look like circles mounted off-center. These you can do in your four jaw, you set them up so the off-centeredness is the same as your cam lift and then bore the shaft hole."
Then you simply slide them on the shaft, align them at 90 degrees to each other and drill holes for roll pins. Or alternatively use setscrews so they can be removed.
If you want to make the alignment easier mill four flat spots on the shaft; this is easy to do in a vise just by milling one flat and then aligning this with the vise jaw for the next and so on. Then use setscrews and your alignment comes automatically from the setscrew sitting on the flat spot.