Hey guys

I am working in a curved part that needs to be cut with notches [0.3 in deep all around - Look at the picture plz]. The part has two profiles one is the circular diameter its bend around and the second is the cylindrical form it has.

I am posting two imagines kindly view

I want the knurls/ notches like the First one on the right on the second one that has the additional profile (It has a bend)

     a)I Tried a spiral (the cutting shape follows the spiral for the cut) but that wont work because it twists

         out and eventually moves away from the part without cutting.

     b) Tried Cutting away from the surface with a depth of 0.03 but it barely grazes the surface