Structure
How the Welding Cart Frame Carries the Load
A 1×2 frame is light. It works here because every heavy thing lands on a member directly under it, and the posts are tied together at the top and braced at the bottom.
- 1×2 tube, on edge
- Post footprint
- Caster mount plate, 2 × 11 ga
- Bench corner pad, 2 × 11 ga
- Caster top plate
- Post-base gusset, 3 × 6
D is the backbone
D sits right behind the bench. It carries the bench's back edge and all three spine posts: the cylinder upright, the shared upright and the shelf post. G supports D in the middle from behind, running back to the rear rail B.
Posts: plug welded, gusseted, tied at the top
Each post is plug welded through the deck to the frame member under it and gusseted at its base with a 3" × 6" 11 ga triangle. On the spine posts the gusset sits on the back, because the bench rests against their fronts. On the two welder-end posts it sits on the inside face.
The upper L shelf ties every post top together. That makes the cart stiff side to side through the L, and front to back through the gussets. The top of the structure lands 12½" above the bench top everywhere. The cylinder upright reaches that height itself and gets a cap. The shared upright and shelf post stop ⅛" short, under the upper shelf plate. The welder-end posts stop 2⅛" short, under the mitered top U.
The bench sits on four points
The bench rests only at its four caster plates. The front-left one lands on the front-left caster pocket plate. The other three land on 6 × 6 double-11 ga pads welded into the corners at A/E, C/D and D/E. The bay under the bench is otherwise open, and the pads and pocket plate act as gussets at all four corners of the bay. That's why there's no crossmember under the middle of the bench: with the bench on its pads, it would carry nothing.
Cylinders, welder and cords
The cylinders stand just behind the spine, directly over H. Chains run from eyes on the back of the two cylinder uprights around each bottle, at about 18" and 34" above the deck.
The lead post and end post stand on the welder-end C, at its front and back corners, over the caster pocket plates. The rebar rail between them sits 31" above the deck, and the hooks on it carry the lead and power-cable coils outside the cart. The welder's back is at the back edge with nothing behind it, so its rear panel stays open.
Shelves
The middle shelf sits flush with the bench top on 14½" arms that lap the shared upright and the shelf post for their full 1" depth, so each arm welds along two edges. It works as a back extension of the work surface, with about 15" of clearance for the plasma underneath.
The upper L shelf's welder leg rests on a mitered 1×2 frame on top of the welder-end posts: a 33" top rail, a 14¼" front arm and a 17¼" rear arm that continues along the back edge to a mitered corner with the shelf post's arm. A rebar rim ties the free edge. The two legs weld together at x = 47¾", right over the shelf post.
Stability
The front and rear casters are 24" apart, and two full 250s put a lot of weight high and toward the back. Lock the casters while you work, and push from the bench end. See the cylinder storage notes for more.