Well I need to mill out some profiles in acrylic. I tried 3 types of double tape, and 2 types of hot glue to fixture the plastic down. After some limited success, and several exploding pieces of acrylic (think mythbusters exploding cds) I got some pieces made. After fighting with such a simple job I decided I should probably make a vaccum table. I will probably convert a cheap hotdog air compressor once I get going, but I figured I'd play around with a venturi first. So I scanned some of the venturi threads here and got to thinkin how could I do a "quikie".
I started to go thru some of my stuff and realized a mig tip is .25". Hmm too easy I say. I cut up some 3/8 plastic tubing (about .25" id) and stuck the .035 mig tip in there, and clamped it. Then I dug up a .25" pushlock tee, and stuck the mig tip in and hit it with some air. I felt a little pull on the branch, and I got excited (yeh, I need some better interests...). I pulled out my calibration gear (I'm a Jman at instrumentation) and checked the vaccum. I was pulling about 2.5 psi, but I could feel the air from the mig tip was "rough". Then I stuck in a piece of 1/4" tubing and it started pulling over 4 psi, so I say to my self "self, this is pretty cool". I started cutting off the 1/4" tubing untill it seemed to top out at over 5 psi vaccum. Judging from the air compressor run time I guestimate it uses about 3cfm of air at line pressure (95-120psi).
Not bad for 5 minutes, and 5 bucks.