Making a shaft with notch a cam

Silly me I thought this was going to be simple, seems little with SW fits that category.

The shaft below simply is the cam, the mating part is a roller, cannot be any simpler.

When I try to make the shaft a cam using any of the SPLINE commands, they all want to create a curved line, this is simpler.

So how do I make this shaft a CAM?

SolidworksGeneral