Aloha yourself & Welcome!
Whether you are hooking up a vacuum or not, your layup will be identical. In an ideal world, you want a 3/4" 4x8' sheet of MDO (medium density overlay) plywood, or a nice Birch plywood as your 'Support Board'. This layer will get bolted to the steel crossmembers of the machine with carriage bolts. See the table drawing fold out at the back of the manual for positioning. Set it where it needs to be & clamp the corners. Crawl underneath the table and pilot drill all the holes for the carriage bolts with an 1/8" drill. Then pop up top & countersink those holes with a 7/8-1" paddle bit. You'll only need to go about 3/16" deep on those max. Then finish out the holes with a 3/8" drill. Pop in the carriage bolts and tighten them up. The next layer, in an ideal world...would be be a 3/4" 4x8' sheet (any MDF will come in 49x97) of Medex moisture resistant MDF. You will use regular wood glue and every clamp in the shop (and weights for the center + put the crown of the sheet down) to glue the Medex MDF spoilboard (that's what it will be called) to the support board. Let it sit overnight.
If you cannot get either of these, you can use a high quality cabinet grade plywood and MDF from a big box store, although go for a better quality MDF if you can.
To get you going on assembly, take everything out of the crate and set them aside. You'll need a friend (a strong one) to help you remove the gantry. Set yourself up a cafeteria table or other workbench, as this will make assembly easier & you get to work like a gentleman
Open up the Fastenal box & the box that has the feet with the blue hatched plastic protectors on them. Go grab the legs and set them on the table so that you can thread the feet into the legs, leaving 1/2" of thread on the stem before they bottom out. Then grab 6 sets of the following and put them in the 'well' of each leg:
8pcs T-nut (rectangular nut)
8pcs 5/16 flat washer
8pcs 5/16 hex bolt
From the inside/well of the leg, put the bolts and flat washers in & thread up the t-nuts with the tit/nub side down(!) so that the bolt is threaded even with that tit/nub. Do all 6 legs like this.
Slide the legs onto the extrusions - understanding that the X0 side of the table goes on the inside & the X120 side of the table goes on the outside of the extrusion - for now. Having assembled more of these things than I can count, I would advise you to slip a piece of cardboard scrap (like the pieces that pad the table side extrusions) between the bottom part of the AL extrusion and the back side of the legs on the X120 legs only. This will splay them out a little at the bottom of the leg and keep you from getting hung up when you slide the crossmembers onto the tool. May not make sense now...but it will!
Next - go grab a friend to help you assemble the entire X0 'bulkhead'. You'll need help keeping everything together while you bolt up the upper 3x5 crossmember, gusset plates and then the lower 3x5 member. There's a lot to check when you do this, so don't crank everything down just yet. Start with the upper 3x5 and hang the gusset plates from the center most holes with the 1/2" hardware. Then swing them into postion and add the remaining 1/2" hardware. Then assuming you squared the legs to the extrusions, put the lower 3x5 on the legs and then snug it all up.
Check square & 'splay' on your X0 side legs by putting the square on the floor. Close is close enough. Then measure the diagonals of the table @ the corner of the extrusions to 3-4-5 it, nudging the table so that it isn't a parallelogram. Then measure for parallel & nudge as necessary. Both of these actions will ease adding the rest of the table parts.
Follow the table diagram. Pull your tape from the X0 side and put a tick mark on the top of the extrusion where each crossmember goes. Transfer this to the bottom inside of the extrusion with a square. It makes it easy to just slide & align, knowing you are dead on. When you get to the center legs, dial them up so they don't drag on the floor (you left 1/2" on the other ones, right?) - and finish up the chassis assembly.
Check for square again - and then level the table starting with the outer 4 feet ONLY. When level, dial the center legs down to the floor by hand and then snug them 1/2 turn. Then you can slide on the X rails & have your friend help you get the gantry on the rails so you can fine tune them parallel...and then you can start hanging all the good stuff on the tool
Have fun, take your time and follow the book. Post a message if you get stuck or confused on anything.
-B