when i make vacume fixtures I make a scroll (spiral) in the pockets pending thickness of the material for the spacing of the walls. then on the outside (not connected) cut an oring groove. The groove will take a few trys on exact depth, I found that 40 - 80 durometer?? type o-ring to work the best. Also I only have a crush depth of a .005-.010 as if two much will not flatten down. also place a vacume in the center via cross drill.The magic vacume numbers seem to be 27 + inches an automitve airtype vacume pump works great as coolant does not seem to effect it. it does however require lots of shop air.
hope this helps. |