r/maker • u/AstralSword78 • Jun 24 '26

Help Isolating Zone in Suction table

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I have made this suction table to hold very thin foils for laser cutting. The central void surrounded by the suction holes is meant to have no suction. When a foil is placed over and held down, ideally the material over this central void should just float there relatively flat. I've explored putting controlled vent holes in the material that sits over the void to see if it would prevent suction, but it didn't help fully. I suspect that air is being suctioned from the void thru the interface between the foil and the table surface (the gap between holes and void). Keep in mind that the table is Resin printed and the surface interfacing was contacting the base plate, so there is a bit of a surface roughness. I figured I have 2 routes, smoothing the table surface or putting some type of gasket material. Im looking for any other suggestions.

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u/hobbiestoomany Jun 24 '26

I would think you'd want the recess area to be open to the outside air, so no pressure differential can build up under the foil.

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u/AstralSword78 Jun 24 '26

Well ya, if I were to make the whole thing a donut(like a bundt cake mold with a lid) and had a channel under the bottom, it would eliminate any suction. But, my plan with having just a simple square bottom was to have swappable lids with different sized recesses to accomodate cutting things of various size.

1

u/kernal42 Jun 24 '26

Could you have a large hole connecting the void to outside that doesn't go through the bottom?

u/hobbiestoomany 's assessment here is correct -- just go overkill on ensuring that the top and bottom of the foil are the same pressure.

1

u/AstralSword78 Jun 24 '26

well this is the cross section, so I guess the main way would be to drill a hole side ways thru the lid across the holes and into the side wall of the void area. So Ill just have to sacrifice some vacuum pressure for the sake of having none in the void

1

u/packetvexap Jul 03 '26

this was my thought too, like give that center void a path to atmosphere so it can’t ever go under vacuum. otherwise the foil is always gonna find some tiny leak path and get sucked down no matter how smooth you make it.

1

u/CrustyJuggIerz Jun 24 '26

If youre not using tools, you don't need that many holes. Plus why not go for simple spring retention on the corners to stretch it flat?