i am trying to create a cam, i have the drawing but im not sure how to approach the sketch. 

the drawing dimensions with statements like " spiral A from 7.5 to 70 degrees: decreasing from R19 to R17.3 linear with degrees, counter clockwise" can some one explain how i can sketch this? I am not sure what commands or features to use. can this be achieved with the cam tool ?

i have attached a picture of the drawing