rscrawford wrote:When you said 14 minutes, I suspected you must be cutting those on a tapered jig! Most posters on here would simply use a finish toolpath and waste 6 or 7 hours of machine time, without getting those nice clean lines.
What kind of a vacuum are you using? I have an older dental vacuum unit (wet ring) that will pull 60cfm at 22"Hg. I use a 1/2" hose with quick connectors to hook up to my different jigs, and I use 1.5mm natural rubber sandblasting mask as the gasket. I cover the whole surface of my jig with the rubber, then cut out sections of the rubber to act as the plenum (since I'm going for an airtight seal, I don't need a deep plenum because there is virtually no airflow). This gives an airtight seal and I can cut out pieces less then 5cmx5cm with no movement.
Nice vacuum unit. I wish I had a better unit but for now I will make do with what I have. I use an air powered system from http://www.qualityvak.com/air.html The unit I have is a VM6 which pulls about 5 CFM at about 19"Hg. I also use 1/2" hose and quick connectors. Beside using jigs on our CNC we do a lot of Vacuum bagging and the quick connect work great. I also use a shopvac as a vacuum source for some larger projects. Here are a couple photos of a jig I use for cutting RC airplane parts. the jig has a cutting area of 24" x 48". I just drop this on my CNC and hook up the shopvac and away we go.