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View Full Version : Vacuum hold-down: pump rating?



Henry DesignMfg
03-18-2012, 12:15 AM
I'm building a custom vacuum hold down for my router table, and can't find good information on what kind of ratings the vacuum pump needs. Is this a good pump for a 4'x8' table?
3/4 HP rotary vane pump
Free Air CFM @ 0 Vacuum (in Hg) 8.00
Free Air CFM @ 5 Vac (in Hg) 6.5
Free Air CFM @ 10 Vac (in Hg) 5.00
Free Air CFM @ 15 Vac (in Hg) 3.50
Free Air CFM @ 20 Vac (in Hg) 2.00
Free Air CFM @ 25 Vac (in Hg) 0.50

ger21
03-18-2012, 07:58 AM
It depends on what exactly you are building. That pump will work for small dedicated fixtures, provided there are no leaks. It may not work well for holding porous materials like MDF, as the air is sucked right through it, and that pump has pretty low CFM at higher vacuum.

If you want to hold 4x8 sheets of material, than no, it won't work. Again, it depends on exactly what you plan on building, but you probably need a pump with 150CFM or more, with as high a vacuum as you can get.
There are some links at the bottom of this page with some good vacuum systems.
ShopBot Vacuum Motors (http://www.centralvacuummotor.com/shopbot.htm)