> > Somewhere I saw a very clever design for a vacuum bed for a router. The > top was in two layers instead of simply having a bunch of holes drilled > through to the plenum each hole had a pocket off to one side. The bottoms > of the pockets sloped slightly downward so that a 6mm Airsoft pellet would > fit and roll away from the hole when the vacuum was off. Lay something flat > on the bed and vacuum would pull on it through every hole it covered but > the uncovered holes would suck the Airsoft pellets out of their pockets to > seal them. Shut the vacuum off and all the pellets roll off the holes. > Would be easy to retrofit atop any vacuum bed. Remove the original top > plate and replace with 1/2" MDF. Use a 5mm drill in the router to make the > hole pattern then a slightly larger than 6mm ball end mill to carve the > side pockets. Drop in the Airsoft pellets then apply a sheet of 1/8" MDF > and redo the 5mm drill pattern. > Then the router can do any size work without needing to have pieces of > MDF, plywood, sheet metal etc. to cover the unused area. > > I've been mulling over this for a few days. I've also seen other designs that have pop-up discs that you press to activate, or automatic, but obviously one wants it to be with as few parts as possible, and automatic.
So here's my 3am idea; Imagine a vacuum table where each individual vacuum point has a flexible tube attached. These tubes all droop down directly under the table and next to the table, maybe at chest height, they all loop up to a common manifold. Lets say that the tubes are 16mm ID. Now inside each tube, just insert a 10mm ball. The manifold attachment has a 8mm orifice on each tube. So similar to the above idea, if the hole on the table is open, the ball will get sucked up to the manifold and block the line. If the hole is covered, the ball will initially get dragged 1/2 a metre as the air is evacuated, but not far enough to block the hole. It will then run back to the lowest point in the tube. Probably use solid plastic balls. So now you have a fully automatic vacuum table with no machining required. Yes, ball weight, tube diameter, etc will have to be determined, but the principle is easy to implement. The only drawback is that dust will settle in the uncovered holes. But you could have a blow-out/purge system. And a pin arrangement through each tube to stop the balls shooting out. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
