Vacuum table in progress finally

[fleinbach]

I have thought (procrastinated) about how I was going to make my vacuum table and layout for the past two years. I do all types of cutting with the shopbot and wanted the flexibility to control cutting everything from full 5 x 12 sheet material down to smaller pieces, plus the ability to hold long boards. My final decision was to use 13 zones. I tried to lay them out to fit most any situation. The enclosed picture depicts how they are laid out. Of course there will still be times I will need to mask off a small area. The total cost for all plumbing was just under $300.00.

I started my layout with four sections 5 1/2 inches wide. This area was created to hold down long boards. The breaking up into four sections was to help align with the second row. The second row starts with 2 foot wide sections, expanding to the width of a 48 inch sheet. Combined with some sections from the first row. I can hold down portions of four by eight sheets in 2' x 4' increments. The remainder is broken into sections so that I can hold 5' x 8', 5' x 10', or 5' x 12' sheets.

So far, yesterday, I cut the Plenum into a 5 x 12 x 1 inch sheet of MDF. Today I will be putting on some epoxy paint as my sealant. I chose epoxy paint for two reasons. The first reason is I happen to have 2 gallons of it sitting on my shelf for the past six years. The second reason is, after testing it on a piece of MDF, I found that it seals far better than anything I've used in the past.


After reading other people's solutions on this forum I decided to start with a Fein vacuum. I purchased a Fein Turbo Vac IV on eBay for $350.00. Depending on my results I may purchase a second Fein, or if need be I will move up to a blower. I can certainly afford the blower, but I chose the Fein for its better noise control. I might add that you do not realize what people are talking about when they describe the power of the Fein. When I plugged it in yesterday for the first time and felt the power of it I was blown away. I have four other shop vacs here, some costing twice what the Fein cost, but the Fein is far more powerful than any of them.

I will update as I progress.


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See larger picture here http://www.theaterrooms.com/vacuum.htm



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[fleinbach]

Well due to the rain today. I got a chance to put a finish on my top. Here's what it looks like with one coat of epoxy on it.

Larger picture http://www.theaterrooms.com/vacuum.htm



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[harryball]

I don't think I can get 13 shop vac heads under my 4x8 table :-) LOL Looks great Frank, I'm jealous!

[fleinbach]

I was realy hoping I wouldn't need 13 shop vac heads!

[fleinbach]

Well I got around to installing my plumbing today. This is what it looks like with 13 zones.


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I do have a question. What thickness of a bleader board is everyone using? I thought someone just recently, like in the past two weeks said they were able to hold down parts through a 3/4" bleader board. Well, in one of my smallest zones, which is only 6" x 24" I put down a gasket, and it will hold a board down extremely well. So I plane down a piece of MDF on both sides to one half of an inch, and it holds this down very well also. But if I try to put a board on top of it it doesn't hold at all.

[btk]

Frank,

Are you using Regular MDF or Trupan?
Trupan(i.e. light-weight MDF) really makes a difference.
I use a 1" thick piece of trupan that gives me plenty of thickness to surface several times before having to change. Once it gets below 1/2" it starts to curl and needs to be changed.

Brian

[harryball]

Frank,

That sounds like it may have been me. I'm using the 4 shopvac heads. I cut 1/2" plywood for bat houses and one of the common parts is 6" x 20" and it holds it so long as I don't break the vac anywhere.

I let it suck the entire sheet down, then do my cutting with a down spiral in a single pass at 6 ips. I've never had it slip yet. I do not take a 6 x 20 and put it on the table and try to carve it or anything. I can place the part on the table and it seems to be stuck very well if I close the rest of the zone off with 1/4" hard board. But I've never tried carving or cutting that way.

For plaques, I have a template that the plaque fits inside of. I place the entire thing on the table and let the vac hold it. Works well but I've recently discovered I need to make a "snugging" feature in my template for small plaques.

As for boards, I've had NO luck getting any board to stick to the table. None whatsoever. I have 200 bdft of flat 1x8x8 coffee stain pine that will not stick to the table. I figure it's just too porous under the board to create a vac. I always create a holddown pass to mark screw holes and secure it that way.

Robert

[fleinbach]

BTK

What kind of vacuum systems are you using? I am using lightweight, MDF as a spoil Board. If you noticed in my pictures above I do not have the spoil board installed as yet. If you look at the lower right corner, you can see I have masked off a 6" x 24" area, which is one zone. I found a piece of light weight MDF and placed it on the masked area after planing both sides with my thickness planner. All other zones are shut off to give maximum pressure on this one small area. This is sucked down extremely well. It takes enormous pressure to pull it off of the table. Since this is simulating a spoil board. I place a piece of 0.75" x 8" x 30" MDF on top and it's as if there is no vacuum at all coming through the spoil board.

Robert,

If I understand you correctly, you do not have a spoil board at all. There is no doubt that my setup will work very well if I do not use a spoil board but I am hoping that is not the case.

[harryball]

I DO use a spoil board, 3/4" MDF. I recently replaced it, surfaced both sides, sealed the edges with shellac and sealed the seam between the spoil board and vac board with tape.

I use several pieces of 1/4" hard board on the table when I'm not cutting sheets that cover an entire zone. I use them to help create the vac over the entire zone.

Robert

[btk]

Frank,
I use a standard 4 Zone Vacuum table with a Fein Vacuum. As my plenum, I use 3/4" Cellular PVC (Azek, FYPON, etc). I beleive that I used the shopbot supplied file to cut my plenum.
On top of my plenum, I Silicone in place a sheet of Trupan which has had skin surfaced off of each side.

My setup looks similiar to yours, however I think that my holes cut in plenum (where connects to PVC pipe below) are larger than the ones that you have.

I also do not rely on my vacuum system to hold down such small parts and instead use either clamps or a specialized jig. My zones are 2'x 4' and work very well to hold down that size or up to full 4'x 8'.

Brian