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View Full Version : the utility of a universal vacuum table



Ajcoholic
12-07-2014, 12:45 PM
I thought I would post something here, since I imagine many other Shopbotters who do not have a Buddy, might not read what gets posted in that sub forum.

Several months ago, I modified my 48" by 48" table and added a universal vacuum hold down. (see the thread http://www.talkshopbot.com/forum/showthread.php?t=19903 )

The point of this thread is to express how much this addition has improved the function of my router. And, to possibly spur on other users, who might be (as I was) very unsure of spending $$ on something not fully understood, or perhaps questioning how good it might perform.

In my case, I purchased a used 10HP regen blower/vac from a fellow member here. Even with a decent sized vac, since the regen units are of low vacuum (but high flow) I was thinking it might be useful to hold down larger cabinet parts. However, it has proven itself VERY useful to hold down parts as small as 20 square inches, without movement, while cutting completely through the parts without tabs. Even long thin parts (2" by 24") are held fast and it has really, really improved the usefulness of my machine.

I use it for holding solid wood parts that are a square foot or larger, plywood parts of any size - as long as the part has a smooth, flat surface that sits tight against the plenum, it will work. If I am worried about the smaller parts moving I just place a few scraps of plywood onto the plenum up against the part being machined, to aid in taking the sideways load. Down cut bits are much better (and what I used mainly anyhow) and also help hold down the smaller parts being cut, and held just with the vacuum.

As far as the plenum goes, I would say the plastic (Starboard) one I made, with a U shaped gasket (specifically made for this purpose) is working perfectly as well. The spoilboard (in my case regular cabinet grade MDF, as the light weight stuff is not readily available in Canada) is also working great. So much so, I havent even bothered to seal off the edges of my spoilboard, and I rarely bother with laying waste ply onto the surface to seal off the unused portions - unless I am cutting smaller parts and then I just throw a few pcs of melamine onto the plenum.

I was concerned that the 2" PVC pipe that was easy to get here wouldnt allow enough air flow. SO far it hasnt been an issue either.

In my case, all of my worries were put at ease as soon as I started using the vacuum top. But it is still a bit worrisome thinking you might be spending several thousand dollars and not sure if it will be worth it or not.

I hope other users (much as I wanted to but was intimidated by not knowing exactly what the end result would be) will give it a try... it really is worth it.

I would not be so "forward" with my enthusiasm about this vacuum thing, unless everything I have written was absolutely true. And man, is it amazing to use in the shop!

Simops
12-07-2014, 08:54 PM
Andrew,

I haven't given up......still works in progress. Still working out my plumbing.....might have to go under 2" though! Still looking for flexible hose to use. The Festool one is too expensive to use in AUS!!

Soon as I get a couple of days without interruption I'll get into it.

Good to see yours working out as expected! Having the 10Hp blower is definitely the way to go....bigger the better.....but not possible for me. I have the electrician coming out to see what more power he can squeeze out from my single phase sub-board for me.....its tight and I only have a 2 1/2 Hp blower!!!

Cheers

bobmoore
12-07-2014, 09:54 PM
Nice post Andrew. Vacuum hold down is also very useful for sanding, carving, and many other non cnc functions. bob

Ajcoholic
12-07-2014, 10:13 PM
Andrew,

I haven't given up......still works in progress. Still working out my plumbing.....might have to go under 2" though! Still looking for flexible hose to use. The Festool one is too expensive to use in AUS!!

Soon as I get a couple of days without interruption I'll get into it.

Good to see yours working out as expected! Having the 10Hp blower is definitely the way to go....bigger the better.....but not possible for me. I have the electrician coming out to see what more power he can squeeze out from my single phase sub-board for me.....its tight and I only have a 2 1/2 Hp blower!!!

Cheers

Dont give up, lol you dont know what you are missing! Even with your 2 1/2HP unit I am sure you will be amazed at the function. You will just need to be more efficient to get the most out of your machine. Plus you are cutting thin aluminum sheet correct?

I wish I could help with the hoses... I know stuff "down under" is more than in North America!

Simops
12-08-2014, 03:13 AM
Andrew.....yes cutting aluminium.....but cutting wood more and more too.
I'll get there......always do :D
Yea the Aussie peso has taken a beating this year.....plus we get gouged constantly with prices on imports!
I'm going to try a corrugated vac hose.....if that does not work then I'll just have to pay Festool Australia's high price!

I've already made the square alum tubing that goes under the table......pic below....

Cheers

Ajcoholic
12-14-2014, 02:00 PM
Looks good... nicer than mine, way nicer. :)

But utility trumps looks, lol :D

I just hope anyone who is on the fence like I was for a few years - will give this a try. I was determined at one point that I needed to spend $12,000 om a big Becker high vacuum pump. I guess since I had zero experience with these larger regen units I didnt want to take a chance. But I am certainly glad I did!

shilala
12-15-2014, 07:51 AM
I just made a small, removable vac plenum.
It's been sitting in clamps for days, I plan to play with it today and see if it works.
I'm pretty excited about it. :)