I am trying to create a mold design of a finned rotor for a project I'm working on. The mold will be injection and the material of the rotor has little shrink for the prototype. I have attached a step file of the finished rotor as well as one that needs center machining. I would prefer to have a mold that works without the need to machine the center if possible. Every time I try to create a parting line it picks up each fin surface and doesn't slice right. I have tried to cut the rotor into a 16th so that it is one fin on each side and see if I could figure out the solution. I still cant get it to work and would truly appreciate a point in the right direction. Thank you for your time.