Re: Vaccuum table holes

--- In CAD_CAM_EDM_DRO@y..., "turbulatordude" <davemucha@j...> wrote:

Dave,

Doug covered most of the points in his post, just a couple of
additional hints.

Try and use proper vacuum hose, soft pvc collapses on itself and then
no vac on the workpiece.

Get a vacuum gauge, most car accessory shops sell them for tune ups,
I use a light industrial vac pump which pulls 28 - 29 "mg, approx
14psi. Woodworkers sometimes use shop vacs, they can't draw down
very low but the generally larger work surface gives sufficient
holding force.

Depending on the size and thickness of your workpiece you can use
either the waffle iron approach Doug recommends or you can get away
with spacers between the work and vac table, thinner than the sealing
foam, so the work doesn't distort from the vac.

for quick chucks I normally just drill into the edge of a piece of
MDF, srew in a NTP nipple and then cross drill from the vac area and
seal off the working area with 1/16" high density foam. You get some
leakage from the MDF but not enough to be a problem.

I use vac extensively for woodwork but haven't used it for metalwork
yet.

bwr

> Hi Group,
>
> I am working on the table/platform of a router and want to hold
parts
> with a vacuum.
>
> Can anybody guide me along the right path ?
>
> it seems that a vacuum would remove pressure from one side and the
> air pressure would the force the part down. At the same time, the
> surface area that the part has in contact with the table would
offer
> friction also.
>
> more holes, more pressure less friction, less holes, less force
> greater friction.....
>
> I want to trim the edges of sheet metal parts, aluminum, so the
> cutting forces would be on the side trying to slide the part on the
> table.
>
> TIA
> Dave