I've been working on a setup for making my own prints, and I recently finished building a vacuum table.
My main model for this project was the vacuum table built by Pelican Print Shop. Their process post detailing the construction of their own table was a key guide in not only selecting materials and components, but in figuring out the assembly steps for the hardware as well. I'd seen/read about vac tables with top surfaces made of recycled desk wood, linoleum, countertop, plexiglass, whiteboard, etc., but I followed Pelican's example and committed the biggest chunk of my project budget to a quarter inch sheet of aluminum for my top. I knew a slab of Al like that would be sturdy as anything, would be easy to clean in case of ink spills, and would look great too. I sized the slab based on the size of the 25" x 36" screens I have and how thick I wanted the frame of the table's hollow to be, arriving at a final measurement of 30 by 41 inches for the tabletop area.
Once I had my aluminum, the first physical step was marking out where the underside of the slab would connect to the frame of the air chamber and the frame of the screen. I sharpied in an inch-by-inch grid for the main spread of holes and marks for the pilot holes for bolting the top to the frame.
(An area of 21 by 31 inches is... )
Next on the shopping list was the wood for the bottom and sides of the air chamber: a sheet of 3/4-inch-thick plywood and some 2-inch-thick square beams made of who knows what (I was not exactly picky at this step). The base of the table was set to be the same size as the top, but I made sure the frame of the hollow actually ended up an inch shorter than that 30" by 41" size top surface size (you'll see why in about 20 images or so).
After everything was sanded appropriately (I left the lowermost edge of the side beams rough to give the wood glue more to grip), I began building the perimeter of the air chamber. Each beam + base contact got a line of "wood filler" close to the outer edge and a line of Gorilla Glue hugging the inside of that. The wood filler I used was a little too thick when I first started to apply it, but customer support at Famowood helpfully let me know that I could thin out the solvent mix with nail polish remover (which seemed to work).
For a more even pressure (and more weight) on the beams while the glue was drying, I laid in some of my extra 2-by-2 beams for support, set the aluminum on top of all that...
And finally clamped the slab near the working edge with pony clamps.
I did this for each side beam, giving each about twenty-four hours of glue + clamp pressure, scraping away the squeezed out excess wood filler every next morning. To save time, I even started drilling the grid of holes while the aluminum was clamped in place.