My combo vacuum clamping table is finally complete.

[gundog]

It has taken me 1 1/2 years to get the clamping table complete due to work load and family stuff. The clamping portion is made from aluminum extrusions from Hubard CNC. The extrusions are screwed to a base plate of 1/2" 6061 plate aluminum. My machine frame is welded and was not flat what I had to do was put a jacking set screw next to each mounting bolt that held the base plate to the frame. I then chucked a dial indicator in the spindle and ran it to each bolt location and leveled the base plate to within .005". I machined the aluminum base plate to get it flat like you would a spoil board removing .020". The extrusions were then mounted to the base plate drilled and tapped using machine screws. There are roughly 350-400 drilled and tapped holes in this clamping table and in hind sight could have been simpler but I will explain that later.

If I had this project to do over again I would do it differently but it will work for my intended use.

What I would do differently is I would just use 2 layers of 1/2" thick aluminum bar stacked on top but offset to form a T shaped channel. Screwing it all to a base plate like the one I used. I believe it would be cheaper faster and less expensive. I have about $2k in this clamping table. I think the Hubbard system would be fine for a smaller table but due to the number of fasteners it takes to install it, it is not worth the time spent. Second problem with these extrusions is it is designed for a 5/16" square head bolt to slide in the T channel. A 3/8" or 1/2" slot would be better because you can buy ready made clamping kits for those size T slots not such clamping kits for 5/16" which means I will have to machine my own clamping kit.

The mistake I made in my design that I noticed afterwards was I should have laid the extrusion in the other direction I am not sure why I did this in the long direction. Hubbard did not offer the extrusion in longer than 8' sections and my table being 75" wide and 125" long I had to splice the pieces on the one side to make it long enough. Had I laid it in the 75" direction I would not have had any seams this was my fault and an over sight.

All in all I am happy it is done and I think it will function great for my intended use of clamping fixtures to the T slot extrusion. The vacuum table is shop built using the Lighthouse 220V built in house vacuum motors. 5 zones controlled by knife valves that I may automate at some point in the future.

I did purposely take these pictures so my Router brand name is not shown as it is not SB and I think would be bad form to promote on this site. Please don't ask me to discuss it on here but feel free to ask any questions about the table vacuum or clamping table.

Mike

http://img.photobucket.com/albums/v292/millnut/20151123_164847.jpg (http://smg.photobucket.com/user/millnut/media/20151123_164847.jpg.html)


http://img.photobucket.com/albums/v292/millnut/20151123_164820.jpg (http://smg.photobucket.com/user/millnut/media/20151123_164820.jpg.html)

[Brady Watson]

Mike,
Looks great. I considered doing this to my big table...I think it was somewhere in the $2000-2500 range too. Thanks for tip on the bar. I will have to price that out and see if it makes sense.

How do you have the vacuum plumbed through the extrusion?

-B

[gundog]

Brady,
When I bought the table the whole cutting area was MDF. I trimmed off the portion where I attached the clamping portion and installed the aluminum plate. There is no vacuum hold down in the clamping area. I added some particle board for the vacuum area on top of the existing MDF top and machined in my grid into 5 zones. Similar to the SB table this router has cross members but made from tube and welded the vacuum ports are between the tube cross members from the bottom. The spoil-board is Trupan glued to the particle board plenum. I will post a picture of the vacuum grid.

I mounted the knife valves to the front of the table with the handles sticking out and a vacuum gauge.

This was my 3rd vacuum table the first 2 being on my PRS so I knew exactly what I needed for vacuum zones. The thin one on the right side is for holding long thin material. If that zone is not used the rest makes a 48" x 96" zone with all turned on I can hold a 54" x 96" sheet and that is the size most of my 1/2" marine board comes in occasionally I get 48" x 96" sheets or if I cut plywood for some project. I use 2 Lighthouse motors in parallel with the ability to use one or both many times cutting the plastic sheet I don't get much leaking because I cut to an onion skin so I only run one vacuum motor. The vacuum motors are outside in a loafing shed with the dust collector, air compressor and vibratory tumbler. The shop stays pretty quit while machining most of the time.

The vacuum zones

[gundog]

Here is how my vacuum motors are ran the main trunk line is 3" and the branch circuits are 1 1/2".

[Ajcoholic]

That extrusion is the same I bought and installed on my Buddy (approx 5' long by 52" wide)

I use the regular 5/16" T bolts (they fit into the slots) and 5/16" T nuts, just file/grind a wee bit off the edges until they slide into the extrusion.

I really like the system, it has worked very well for the last year and a bit. Bullet proof.

[gundog]

I am not saying it is a bad system what I am saying is it could be better. For a wood worker I am sure it suits that need and to be fair that is probably the type buyer they were targeting. I make mechanical type parts using vises and fixtures requiring different hold down methods. A milling clamp kit works very well for hold down of vises and other fixtures had this extrusion been designed for 3/8" bolts a ready made clamp kit could be purchased I have not found anyone making such a clamp kit in 5/16". Here is an example of the type kit I am talking about.

http://www.amazon.com/TE-CO-20413-Machinist-T-Slot-Pieces/dp/B003HGGS4Q/ref=sr_1_6?ie=UTF8&qid=1448565206&sr=8-6&keywords=5%2F16+milling+clamp+kit

I have this type clamp kit for my milling machine that uses 1/2" T nuts.

When I ordered the extrusions I thought it was one big piece by looking at his pictures I did not know it was a bunch of pieces you had to put together I was rather surprised when I received the order and saw what it was going to take to assemble it. I think I would not have ordered it if I had known what I know now. I am sure it works well for the intended use and that is my fault for not knowing what I was getting before I ordered.

Mike

[willmorgan]

Hey Mike that looks great. I am thinking about the same thing. I also have a milling machine and use the same type of clamp kit for it. Good to know about the slots, I will try to look for something that will allow it to fit.

Thanks for sharing.

Will

[Ajcoholic]

Ive got two milling machines in my tool room in the shop, I know what you mean. The studs and T nuts are huge VS what I use on the CNC table.

I was also looking at the extruded aluminum tops where they are big one piece extrusions, and larger/thicker. But way more $$ and somewhat overkill I thought for my needs.