# Shop Made Vacuum hold down



## SteveMI (May 29, 2011)

This is something I made a couple years ago and it worked well for quite some time. It is essentially some sign board that has aluminum sides and a corrogated center. I made an MDF frame for it and sealed that with multiple coats of shellac. Once mounted on my CNC I ran a routine that drilled holes. It only needed a good shop vac to create enough vacuum to hold the work in place. I used cut strips of an inner tube to cover the holes not covered by the work piece.

I was unable to move the vacuum clamped items physically. My machine table is only 16" by 24" and I never cut more than 1/4" depth in one pass.

Proffesional vacuum clamping on larger CNC tables use actual vacuum pumps and pull vacuum through the MDF spoil board. The structural elements of designing one of those is a lot more complicated.

My vacuum table became mortally injured once too often with an errant Z axis movement. My design didn't really take into consideration a replaceable spoil board.

Now I use a solid spoil board with mechanical hold downs for the material and cut with either tabs on the perimeter or leave a skin.

Steve.


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## papawd (Jan 5, 2011)

Pretty cool


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## dutchman 46 (May 23, 2007)

Nice setup! The vacuums today have a much suction than the older steel shop vacuums do: Thanks for the pic,s


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## allthunbs (Jun 22, 2008)

Hi Steve:

To augment what you're saying above, it is also possible to use a venturi on a compressed air line to create the vacuum. For the shop made clamp, see Bill Hylton's "Router Magic."

Great info. Thanks Steve.


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