Since our old vacuum is getting replaced I am now planning to build a vacuum table with the old one. I decided pretty quickly that I wanted several zones that I can manage individually.
The first design had a centre zone that is always active, because I often only use that size.
I then looked at my videos and pictures and figured out that I am usually working closer to the edge. Also I didn’t like that the original plan didn’t utilize the middle fully when using only one of the other zones (top 2 are together, botton 2 are together.
When doing a dry run I noticed that two of the holes are above my supporting beams, so I had to move them. Looks ugly, but no one is going to see this later anyway.
Cutting will be next week or so, I will keep you posted.
And just as I hit post I saw that the bottom line still connects the centre and side zones. Shame on me.
The top two and outer bottom are connected. 5 zones would be overkill for such a relatively small table. The surface will just be a 18mm MDF Board again, with both sides slightly shaved off. MDF is really porous, would not have believed it either. You can see it here for instance: Getting my new CNC DIALED! // Vacuum Table Workholding & T-Track Fixture Table - YouTube
Yeah- I tried that once, with 1/2” mdf and my harbor freight 1200cfm dust extractor couldn’t hold anything down hard enough not to slip while planing.
Different forces and pressures with CNC so I have my fingers crossed it’ll work for you.
What kind of vacuum are you using? A regular house one? I’m of the opinion that high volume low flow- like a dust collector- is a better fit, but I’m not a professional.
I am just using the house vacuum. If it does not work nobody is going to see it later. Did you make sure your bottom MDF layer was somehow sealed? Otherwise half your air is escaping to the bottom. I am going to use some wood sealer for the bottom that I’ve got lying around.
This is absolutely incredible. Three vacuums for one car is insane. I think I should be good with my one vacuum and little pieces of wood if I do it right.
Won’t the motor in the vaccum burn if no air is flowing through? I want to think I’ve heard something like that before? Either way I’m looking forward to see how it goes since I’m also planning a new table for my machine and haven’t decided completely on holding system yet
That did work out, after all. Sooo much dust, even though the dust collection was working. I turned it off for around 4 seconds to try what would happen and all the stuff got blown all over the place. So it did work at least a bit.
Black Box Vac’s Hurricane Vacuum System — with 4 vac motors for a full 4x8 table — costs about $3,680 when including 4 valves for zoning, and including an inline filter, and including shipping for residential addresses.
Curious what your vacuum pipe/gate/sealing setup looks like inside the table/torsion-box. Were you able to make modifications to your existing bench, or have to pretty much completely rebuild?
I had two layers of MDF for stability, 21mm bottom, 18mm on top. I just pulled the spoilboard off, the feet are on plywood anyway (the white strips you can see in the pictures). I just made the grid in the bottom board. I started to do the pipes today, might be able to finish it this weekend, will provide pictures.
Today’s progress: Laid down the pipes, then put the original plate on again. Did suck a little through it, but not enough. Sealed the table with wood sealer. Hope that helps. If it does not I am planning to use some window-insulation strips to put on the outer edges to stop the air from escaping through the sides at least. I might also add three layers of paint or put some foil below the table to seal it. Not sure yet. The general idea does work though.
I guess another problem is the spoilboard itself, because it is a lot bigger than the actual cutting surface, I might have to paint it as well to not have air escape through the sides there OR cut out the cutting area and put some airproof insulation around the cutting area. That might be better actually in the long run. Or I just exchange the whole top with plywood and just cut out the area for the spoilboard. That might be the best but most expensive solution that I don’t want to try as of yet. Now, pictures:
edit: I just had an idea: I am going to cut out the spoilboard with my planing bit (16mm) so it’s wider than the actual size that I usually use, then I can build a plywood frame that is ~8mm around the actual spoilboard made of MDF. Most cost effective I guess.
Did you make sure your bottom MDF layer was somehow sealed? Otherwise half your air is escaping to the bottom. I am going to use some wood sealer for the bottom that I’ve got lying around.
, one vacuum and three gasketed ply boxes, with large surface area.
If mine works it cost me 12,45€ plus a few bits and pieces that I had lying around. 
