I want to have a jig made, but am not sure who to talk to - machinist, etc. I want a jig that will tighten against the limb tips and has grooves for my round file to ride in while filing the string grooves. This will provide repeatable accuracy from bow to bow. What I need to know is what kind of machinist/machine shop should I talk to? What kind of material (obviously steel of some sort) and what kind of rockwell to prevent the file from damaging it over time, etc. Do any of you know of a jig already in production? Thanks for any suggestions.