This is the vacuum hold down system I put together for my old Shopbot PRT96. It has a bypass valve in the center, a 3 phase motor with static phase convertor, magnetic starter, intake filter, rubber anti-vibration coupling, and a fluid-filled vacuum meter. The shortest pipes, connect to the front zones which are used the most. My platen/grid thingy(not shown), on the table top is made from 3/4" expanded PVC which is one of the substrate materials we use in the sign biz.