The QUAD
I have been working with Luthiers Mercantile Int., www.lmii.com, to setup and move current and new product production onto their new PRS Alpha. It came time to build a vacuum holdown system and using Brady's open source vacuum project thread as a starting point, I designed and built this system, nicknamed the QUAD.
The 5' x 8' table is split into 6 equal zones, each with a 1" grid 3/8" deep into the table and a matching grid 1/8" deep into the 3/4" Trupan spoilboard. Each zone has a vacuum gauge.
ABS drainage plumbing is used throughout to take avantage of its smooth flow design. The table zone manifold is 3" ABS and is mounted under the front rail with Al straps and guillotine style u-bolts from McMaster-Carr. Specific zone plumbing is 2" ABS with 2" gate valves with stainless steel paddles. The valves are from www.westpacsupply.com
Four VBTST13431AEAD motors are mounted to a 15mm plywood housing containing a 3" ABS plenum. Each motor is on it's own power switch and 15amp breaker. 1 1/2" ABS and gate valves are used to switch intakes/exhausts for 2 parallel, 4 parallel, or 2+2 series parallel operation.The 4 mufflers are also from Lighthouse Ent.
For maintenance, all valves were bonded with silicone rubber and the right side of motor housing is a bolt-on.
With all table zone valves closed, the vacuum is 10+in Hg for 2 or 4 motors in parallel and 17+in Hg 2+2 series parallel. The series motors do heat up quickly with no airflow, so I use this only for very short runs with some leakage.
The system has run now for about 3 weeks with no problems. It is loud, even with mufflers. Larger parts are easily held with 2 motors. With smaller parts or many cuts, I've switched on the 2 other motors during the run to maintain vacuum.
Installed left view
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Installed right view
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Left side of motor housing
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Front of motor housing
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Motor plenum
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Motor mount
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Zones manifold
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Manifold strap
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Zone Valves
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Gate Valve
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