Question about vacuum tables

[POPS 64]

I was just received a nice vacuum pump with 3 different size plates . I have never seen a full size vac powered table top and on a buddy with the table moving instead of the gantry moving . I'am wondering to make a whole table top or make a removable plate that uses almost the whole thing. Opinions or pictures and any threads would be appreciated. Thanks Jeff

[Dish]

Here is one (http://www.talkshopbot.com/forum/showthread.php?t=19903)

[Ajcoholic]

Jeff,
I just added a new chapter to the "book" today - machined a new plenum from plastic. The thread has all the info on what I did to create my vacuum hold down. Just keep in mind mine is the "universal" style vacuum where you are bleeding a large amount of air at a lower pressure all across the sheet. Not the "high vacuum, dedicated fixture" style.

[POPS 64]

Brian and Andrew thanks for the input it has giving me some good idea's and what may work best for me .With my work surface being 24"x 32" I think I'll make a plate 22" x 30" that will handle most things I do and when I have a over size project remove 4 pins and go back to the old way . Thanks again for the input. Jeff:)

[dana_swift]

Here is my BT-32 table I have been using without modification for at least 6 years. Its holds well and just keeps doing its job.

http://www.talkshopbot.com/forum/showpost.php?p=22179&postcount=16

That may not be what you want or need but it holds the full 24x24 area of the BT-32 with a death grip. Search for my name and vacuum, I have posted plenty about it.

The table is removable so I can use either the spoilboard, dedicated fixtures, or the generic vacuum table. All of them are great solutions.

Andrew's system is first class! I like it too, mine just keeps working so well I just keep using it!

D

[scottp55]

Thanks Dana, Hadn't seen that one before and it has some features I'll be "stealing":)

[POPS 64]

Thanks Dana that looks very interesting and being removeable is exacting what I want in my design . Thanks Jeff

[bleeth]

Hey Dana:
Maybe you should remind the fella's what kind/power of pump you are using as well.

That is a nice looking rig-I had forgotten about it.

[dana_swift]

Thanks to all :)

It just keeps working so I just keep using it :) The bleederboard has been replaced of course, its just held in position by dowel rods that are sacrificial if need be.

I happen to use a 5hp Becker vane pump, it goes up to about 28"Hg then I have a pressure switch that shuts it off till it bleeds down to 18"Hg. It pulls down a 100# propane bottle to act as a vacuum accumulator. That size was chosen because it was given to me :), a lot of my stuff gets built from scraps like that.

The vane pump has the benefit of good flow CFM and high suction. I also have a Gast piston pump for dedicated fixtures where 5hp is just too much noise and operating cost.

I am envious of the large 15hp two stage blowers, that would just be way cool, but they dont get the very high pressures I am accustomed to.

One note about the 3 red garden hoses I use to transfer vacuum to the table: The original ones are still in use! A bit scuffed in places but that has worked amazingly well!

Also in the article I mentioned the manifold was intended to run off the back of the table. Well I am here to update my article after all these years running off the front has been just fine. The hoses are not in the way and easy to move if needed.

Feel free to steal- I borrow liberally from other peoples ideas :)

D

[ssflyer]

Dana,

Always intrigued me how well a garden hose works for vacuum, since they are designed for pressure - most designs don't work so well for their opposite...

Pretty sure the end result would be different for a submarine!