Tip 1:
I frequently machine plastic parts and don’t wish to waste time machining two sides parallel so I can hold the material so the part won’t move while it’s being cut. Also, I usually don’t have much material to waste / hold on. To accomplish this task I put a set of aluminum soft jaws in a vise and tighten the jaws against a small parallel with approximately the same pressure as I will use to hold the chuck of plastic. I then mill a .030 deep step with a 1/2″ 3 flute carbide end mill on both jaws. Next I insert a dovetail cutter and mill a dovetail in both the fixed and moveable jaw. I then come back and cut off the burr that the dovetail cutter leaves making sure to push the burr away from the edge of the dovetail. Finally I use the end mill to create “teeth” in the dovetail so that the plastic part can’t slide. The whole process can be done in less than ten minutes and results in a cheap way to hold and mill plastic parts. It’s so fast I don’t even bother to save the aluminum soft jaws and instead just make them whenever I need them.
Tip 2:
Our shop recently purchased some TalonGrip Systems vise jaws for doing aluminum hog outs. We got the steel ones.
http://www.talongripsystems.com/applications.html
Although TalonGrip Systems never mention it, I highly recommend using anti-seize on the screws that hold the grips in the jaws because if you don’t they are very difficult to get out.
