Hey y'all Would THIS work? (Modified Imperial Vacuum Table Plans)

[tuck]

Greets. Some of you know that I'm trying to noodle out the right vacuum table system for myself after 7 years without one. I was close to buying 2 new Fein Turbo's for $750.00 (with free shipping), but lawwd have mercy! I can get 4 Imperial VBTST6460VM vac motors for $234.00 less and have, as everyone says, superior performance and that's my plans as of today, 4 of them suckers!

If interested, please click on the following link and study my plans for a minute:

[IMG]http://i50.photobucket.com/albums/f3...cPlansSBMB.jpg[/IMG]

You can see that I want a 4 zone table with 4 motors, but I also want some flexibility as to how I use them (the motors). I don't want to reinvent the wheel and I'm trying to stay away from extensive and expensive manifold work and keep things as simple as possible.

Everything you see is located under the Bot, meaning the motors and the PVC plumbing. The motor boxes are to sit directly on the floor connected straight up into 2" PVC 4-way Tees as shown, which elbow off into 4 PVC ball valves, "A,B,C & D" and also connect to the plenum vacuum holes . My thoughts are to be able to zone off these motors easily and effectively as I need to and as the case may be. In this particular imaginary case, let's say that I am cutting through some small tough parts and only need 'zone 1' for space but need extra vacuum power to hold everything in place in that zone. I am showing in my plan ball valves B & C closed and 'motor 2' will not be turned on. I will run motors 1, 3 & 4, but I would plug their plenum vacuum holes (3&4), with simple (and cheap), 'pressure test plugs' (signified by the blue dots in the top of the 4-way tees), so as to direct their vacuum power to zone 1. 'Motor 2 Zone 2' won't need a plug as it would be closed off and not running.

Does this make any sense? Am I on the right path with this? If I was cutting through in all 4 zones out of a 4x8 sheet I would open all the valves and turn on all 4 motors. In my mind I see all the flexibility I'd likely ever need but I'm a latecomer to the vacuum table business and a little bit unsure of myself at this point.

Anyone wanna put in their 2 cents? Brady? David? Ed? Anyone???

[tuck]

Add to say, I call them 'motors',...I mean 'vacuum pumps'! ;-)

[ryan_slaback]

The only problem I can see (and I may not be understanding you correctly) is how you would get the plugs in place. Most vacuum tables have the plenum cut in a sheet and then a bleeder placed overtop of the plenum. The vac is actually sucked straight through a board. In other words, there are no holes or cuts in the surface your workpiece actually fastens to. If you build it the traditional way you would not be able to get the plug in.

I guess you could make a tapered plug in the bleeder as well and then you would take that plug out to plug the plastic T but I don't know for sure how well that would work.

[tuck]

Thanks Ryan, and I think you're understanding me right.. In this case I would use 1" thick sheet PVC for the plenum with 4 zone grids cut in. That idea hit me like a truck when I went to visit fellow ShopBotter David Buchsbaum last week and he was explaining to me the intricacies and difficulties of building and gluing up a proper plenum. He used Baltic Birch plywood with backerboard laminate glued to both sides of the plywood, then regular MDF glued to to the top of it all to which he cut his grid in for his 8 zone table. On top of that went his spoilboard ( trupan bleeder), which was attached to the table only by vacuum. It was beautiful and worked great but a lil' too complicated for my simple head. Sealing the edges of the plywood presented a problem as did the proper glue-up of it all and that's when I said to David, "What if I used solid sheet PVC for the plenum?" He thought for a minute and asked, "How thick can you get it?" I says, "1 inch", to which he said, "It'd take a SIGN MAN like you to think of something like that!" lol! It IS non-porous with no glue-up or sealing necessary.

So, to answer your concern, the "bleeder" is not attached to the plenum except by vacuum and whatever I'm cutting goes on top of that. With the vacuums turned off, I can remove the bleeder board and place plugs wherever I need them to be depending on which zone(s) I'm planning to cut in and which not (if indeed I need them at all as the case may be).

Make sense yet?

[steve4460]

Hi Mark
For what it's worth . I have a 6.5 Hp shopvac with the standard 4 zone vac plennum hooked up ,and I cut 4x8 sheets all day with that using tab's on the smaller part ( 12' x 12' )and things are stayig im place with just that .So my thought are start with the cheap way ($ 200.00 vac and 2" plumbing PVC ) after all once the plenumm is in place you can always upgrade the vacumme's afterwards with out changing anything on the bot . I have been happy with that 6.5Hp shopvac for $ 99.00 3 years ago . Just take the fillters of , since you will not use it for dust collecting , there will not be any getting in to it to start any fiers .
well amyway .

Bot on

[tuck]

Stephan,....TABS? NOOOOOO! lol, I kid, but I don't wanna use tabs. I want a vacuum system that'll suck the chrome off a bumper hitch if'n I need it to and hold down all but the most impossible sheet goods, which is mostly what I deal with in the sign business (sheet goods, mostly well behaved). I've gotten away without any vac at all for 7 years and it's time I spent some $$$ on one, but I want to do it right and be happy with my efforts, of course. I can't afford a 230 volt 3 phase blower, so I'm just trying to run with what's already been put out there by Brady Watson, Paco, Stan Holt and others,...just modified and simplified a little bit for what I perceive as my unique needs.

I'm all ears for anyone that can tell me why this won't work beautifully. If no one can by Tuesday morning May 6th, I'm gonna order the pumps with full plans to build this and call it "Uncle Tucker's Hi-Tech Redneck Vacuum Table"!

[tuck]

Late night and I'm still thinking. Let's say I have a 2' x 8' piece of material that I want to work on and through-cut in zones 1 & 2. In that case, I would put plugs in the vacuum holes of zones 3 & 4 as already shown, but now I would open valves B & C and maybe close valve D (?) and turn on all 4 motors (pumps), if I needed to? Or maybe close A & C, leave B open and just turn on pumps 1 & 2 if I'm just working on bigger parts out of, HDU for instance?

Either I'm crazy or the possibilities are almost limitless, I tell ya!

I'm waiting for someone more experienced and knowledgeable than myself to jump in here and rain on my sunny day!

[ed_lang]

Mark,
I would either build a box to mount all four motors on and then go to your PVC pipe, or mount the motors directly on the PCV pipe and not use a wooden box. I would then use your four ball valves to control which zone(s) gets all of the vacuum. The other option would be to run two motors and the second set in series for more vacuum. There are a few neat designs posted here that show how others have made real nice systems that can run parallel or series by changing valves.

I would run all zones to one manifold with valves leading out to each zone.

[andyb]

Mark,
I agree with Ed. Use valves to control each zone. I would have all my valves on one side so you don’t have to run around the table to turn a zone on or off. I went with a vacuum table about 8 months ago using my old 6 HP Craftsman vac and I love it. I’m only getting about 3.5 hg but it’s working for me now. I’ve been cutting a lot of MDF doors lately. With a little planning of my cut order, everything over 12x12 cuts great. Anything under and I use tabs like Stephen.

I’m planning on the Imperial vacuum pumps here in the near future but like I said the Craftsman vac is working for now. I went with 9 zones for what I cutting. I just took 4 zones and split them up for my use. It allows be more flexibility for what I’m cutting. The zone down the X is 9.5” wide for cutting boards.


30339.jpg

Knowing what I know now using by Craftsman vac, I’d go with 2 of the Imperial pumps and expand from there if you need too.

Andy B.

[tuck]

Thanks for the feedback guys. It makes me think harder and that's always a challenge!

Ed, the reason for the boxes is to add filters and mufflers to each motor, but perhaps I don't need the boxes? Noise is always a concern for me and I like things as quiet as possible. As I see my design, the ball valves DO control the zones. The plugs I mentioned would simply be an easy way to direct the vacuum of any motor to another zone. My original design had no valves at all and I thought I could control everything with plugs alone, but then I realized that any motors not running would be a source for a huge vacuum leak if not sealed off. To be honest with you, I really don't understand the "series and parallel" concept, but I'm trying.

Andy, I wouldn't mind walking around the table to flip valves. I'm not high production so it's not something I'd be constantly having to do. I also realize that 4 motors may be overkill, but I have a little Tim Allen in me and I also noticed in Brady Watson's original thread on these motors, Robert Ball said:
"This looks very promising. I could see using 4 of these to build a serious system for less than $1000 which for many shopbotters would be the holy grail. I agree, for commercial production standards just pay the price of admission and get a big pump, for the rest of us there does seem to be hope!"

To which Brady replied: "Yes Robert, you're starting to see the whole picture."

If y'all will humor me, let's take a look at a couple of more configurations as to how this might work. Let's say that I need to cut up a 4' x 4' sheet and I wanna use zones 1 & 3. The following configuration shows how that would be set up easily and quickly with valves B & D turned off and motors 2 & 4 turned off as well:

[IMG]http://i50.photobucket.com/albums/f3...an52/Vac13.jpg[/IMG]

Now, let's say that I have a 2' x 4' sheet of .080 aluminum or some tough ABS plastic I need to through cut small parts or letters from. Let's say that for whatever reason I wanna work in zone 4 but I need full vacuum power from all 4 motors. ("I'm giving it all she's got, Captain!) In this case all 4 valves would be open, all 4 motors running, and I would insert plugs in the plenum top in zones 1,2 & 3 so as to seal off those zones and divert the vacuum of motors 1,2 & 3 to zone 4. It would look like this:

[IMG]http://i50.photobucket.com/albums/f3...fan52/Vac4.jpg[/IMG]

Have I lost my mind? Am I missing something obvious that would make this system not work like I think it would? Like I said, I'm all ears and eyes guys!