# vacuum pump of water



## sarat (Jul 7, 2011)

Hi,Everybody.
I need vacuum Pump for my CNC Router,Recently i heard about water vacuum pump,Where can i get this one.What difference between Air and water vacuum pump?
Please help me.


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## Phil P (Jul 25, 2010)

Sarat

There are two main classes of vacuum pump so far as we are concerned, oil-less and oil-lubricated. For use with timber products you need to go oil-less as the dust is a major problem. In terms of the type of vacuum pump there are again two main types; vane pumps which use multiple carbon vanes and generate relatively high vacuum at lowish volumes (25 to 100 cfm is quite a common range for woodworking CNCs) and regenerative pumps which don't deliver anywhere near the absolute vacuum pressure but which can shift enough air to hold a large MDF panel flat on the spoilboard for machining (often several hundred cfm).

Vane pumps work best on TV-bar beds with individual small vacuum pods whilst the regenerative types (sometimes referred to as "water-ring") are most suited to full bed draw-down through a permeable spoil board, such as lightweight MDF. 

I think you need to start looking at firms like Busch, Decker, Siemens and Travaini to get large CNC-useable pumps. The type of pump required depends on the configuration of the machine, size of bed, material being worked, type of work (is side-drilling a requirement or are you nesting multiple components), etc. There is no simple answer other than to say vane pumps are generally a lot smaller and cheaper to run. Oh, and bigger is _always_ better

For some additional information about the hows and whys see here. For an idea of how much vacuum you'll need, a 4ft x 4ft vacuum table holding 18mm MDF components on pods requires 25 to 50 cfm at 22in Hg, a similar-sized throughflow requirement might well be in the order of 200cfm or more at 100in Wg). You need to be able to withstand a side force from the cutter in the order of 50kgf, so a 3cfm DIY vacuum pump won't hack it at commercial feed speeds

Regards

Phil


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## bobj3 (Jan 17, 2006)

Search results for: 'vacuum pump'

Amazon.com: vacuum pump - Tools & Home Improvement


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