I have been thinking of doing a heavy duty welding table that has more capabilities than my little metal table in the garage. My requirements were the following:
* The table must be able to hold at least 2000# in addition to its weight. I work on engines sometime and if this was a general purpose table as well, it would be nice.
* The table must have surfaces for cutting with my torch and plasma.
* The table must have a funnel to catch sparks from cutting and channel them into a removable cleaning pit.
* The table must have the ability to add clamps and other jigs easily.
* The table must be able to take the heat of torch, tig and SMAW without significant warping.
Below is a picture of some initial design ideas I whipped up in my CAD program. I created the table with 1/3 as a cutting surface and 2/3 as a welding and clamping surface.
The cutting area is a grid of 1/4 inch by 3 inch steel bars set on the side in slots cut in the side rails. The idea is when a slat gets damaged by cutting it can be replaced. What isnt shown in the drawing is the funnel underneath. It will be a 4 sided funnel made of 12ga sheet and leading down to a collection pot.
The welding area is composed of three 12 inch wide, 1/4 inch thick steel plate. Each plate is placed 2 inches from the previous to allow the insertion of bar clamps and so on. In addition, the plates are drilled through with 1/2 inch diameter holes every 3 inches so that stainless steel bolts can go through the surface to rig up clamps. I have thought of welding the surfaces to the frame but I think it would be better to fix them with stainless steel bolts so they can be replaced when needed.
The top frame is .321 wall 4" by 1.721" C channel. I opted for C channel because it is provides a clamping surface as well as being less prone to corrosion than enclosed rectangular tube since air and moisture cant get trapped inside like a tube.
The legs are currently designed as 4" x 5" x 1/4" rectangular tube though I might try to go C Channel here as well. I will have to brace them a bit more against racking other than the welds holding them. I havent put those braces in the drawing yet. The legs sit on heavy duty double locking casters from northern tool.
The whole thing weighs, by my calculation of volume vs .35# per cubic inch of steel, 471# as currently designed which is making me wonder if I am getting too extreme in the engineering here. Perhaps I can use C channel with a shorter web (3" maybe) or thinner walls. The top surfaces do need ot be 1/4 at least for heat warping reasons since I use a torch a lot. However I am thinking the legs are perhaps too big and I could get by with C channel and a plate welded to the end of the channel to bolt the casters to.