300-400 individual pods are manually flipped to provide vacuum flow to panels being held. A 10- to 20-hp rotary screw vacuum generator is needed. This selection is recommended for applications where low lot sizes discourage the use of vacuum fixture boards, blanks are already dimensioned for machining, and horizontal boring or routing is required. The activated pods allow access to the part top, sides, and even bottom edge. The blanks are already positioned up in the air with adequate clearance for most horizontal machining. Another advantage of pods is that a conventional fixture board could be placed on top of selected pods to effectively hold-down small or three-dimensional parts.
Disadvantages? Seals must be replaced periodically, hard to securely hold small parts without enough pod coverage, and slick or dense material can shift during machining.
The pod panel should be constructed of UHMW polyethylene. This vacuum system is more expensive than the traditional vacuum.