I just finished building my plasma table and have been running it for about a week, I figured I'd show a few pictures. I spent a lot of time here looking at pictures of other people's builds for ideas, hopefully someone can get something from mine. My initial goal was to spend $1000. It ended up being closer to $1500.
The table is made from 4"x2" 14 ga steel tubing, fully welded. It's 64" long by 60" wide. The material support slats are 1/8" x 2" flat bar on end, 4" apart, supported at each end and in the center. The table has a built-in water tray, 18 ga steel sheet welded to the bottom of the table. The air tank underneath the table is the air bladder to adjust the water level.
For the X axis linear guides I'm using a 72" ground Vee rail and Vee rollers on one side, bolted to 1x1 steel tubing which is welded to the main frame of the table. The opposite side is the same except that it uses flat rollers on a flat rail. The X carriages are cut from 1/4" steel plate. Each carriage has two fixed rollers on top and two smaller rollers in adjustable slots on the bottom. The gantry is made from 2"x2" uprights and 4"x2" cross beam, welded to the carriages. The Y axis uses two V rails, one bolted to the top and one bolted to the bottom of the 4"x2" gantry tube. I have rails on both sides of the gantry, the second set will be for a drilling head.
The X and Y axis are driven by timing belts and steppers. The belts are 3/8" width .2" pitch XL series polyurethane with kevlar strands. The belts are fixed at each end, wrapped over drive pulleys and tensioned using two double skate bearings as idlers on each belt. Both axis are direct drive with 15 groove pulleys on 210 oz/in NEMA 23 stepping motors, two on the X and one on the Y.
More later...