Hey guys,

I am in a Jig and Fixture design class in school right now.  We recently were assigned a new concept that has me stumped.  We did not go over it much in class but I want to try and get more figured out before I go into class. I attached the part we are supposed to draw, the dimensions are of the part machined.  They want us to draw two configurations, one of the machined part and the other of the casting.  I am having a hard time grasping the idea of how to add material for the casting, how much material and where and why.  Anyone able to help?
Thanks