DIY Welding Cart: Plans vs Laser-Cut Kit

What you need to build your own cart

A welding cart is one of the first projects most welders make for themselves. Before you buy any steel, answer three questions: which welder will sit on it, how many cylinders it will carry and how big they are, and where it will be moved around. Those answers set the size of the shelves, the wheelbase and how high the centre of gravity sits. Our guide on how to choose a welding cart walks through each of them.

With your own plans, all the engineering is on your side: a dimensioned drawing, a materials list, how the parts join, the welding sequence and a check that the cart will not tip over with a cylinder on board. Then comes the workshop part: cutting, drilling, bending, fitting and only then welding. Every mistake in the drawing shows up during assembly, and fixing it costs time and material.

The most underestimated part of a home-made design is stability. The cylinder is the tallest and one of the heaviest items on the cart, and an empty cart behaves differently from a loaded one. Calculate it, or at least test it in practice: will the cart, with the cylinder and welder on board, stay upright on a slight slope and when you pull it over a threshold? For our size S we calculated the tipping angle on the CAD model with a 20 l cylinder and a 30 kg (66 lb) welder: about 16°. Without a cylinder the cart is still light at the back, so you fit the cylinder first and then the welder.

A kit moves the design and cutting work to the manufacturer. You get a complete set of parts from a single CAD model, each one engraved with a number, and your work starts with a dry fit.

Materials and tools list

This is how the two routes compare, using our size S cart as the example:

The tools you need either way are mainly a welder, a square, a wire brush, taps and a hammer. With your own plans you also need tools for cutting and drilling steel, and a press brake or a bending service for the bent parts. With the kit, the laser, the CNC tube bender and a press brake (6 of the 9 bent parts arrive already bent) have done that work, so what is left on the bench is a welder, a rubber mallet, a square, M4 and M6 taps, a wire brush and a vice for bending the sheet along the notched lines.

Cost and time: plans vs kit

To be honest, there is no single price for a cart built from scratch. It depends on the price of steel that month, on whether you cut the parts yourself or pay for cutting, and on what your time is worth. Below is a comparison of the stages rather than a ready-made quote.

Building from plans wins when you have a cheap source of steel, access to a saw and a press brake, and you enjoy the design work. A kit wins when you want to weld rather than draw and measure.

Laser cutting accuracy

The biggest difference between a home-made cart and a kit is the fit. Parts cut with an angle grinder or a saw have deviations that you then have to correct during assembly: packing, pulling with clamps, grinding. A laser cuts from the file, so every part has the shape of the CAD model and comes out the same every time.

The kit uses that accuracy in tab-and-slot joints. The tab of one part fits into the slot of the next with 0.25–0.3 mm (0.010–0.012 in) of clearance per side. That is enough to assemble the frame dry with a rubber mallet, and little enough that the parts do not float around before you tack them. The angles are set by the geometry of the joints, not by a square and patience. More on the technology itself is in our guide to laser-cut weld-it-yourself kits.

Welding sequence

Whether you are building from your own plans or from a kit, the rule is the same: first everything dry and tacked, and only then the final welding. Thin sheet pulls under a long weld run, and a frame that has twisted cannot be straightened without damage.

This is how the size S cart goes together:

1. Unpacking (about 1 h) – checking the parts against the parts list and laying out the sheets by thickness.
2. Frame (about 2 h) – the deck, the beams and the castor brackets on the axle line. Tack the frame dry and check the diagonals.
3. Side panels and hoops (about 3 h) – the panels from the centre outwards, the drawers, the hoops. Final welding in short runs.
4. Finishing (1–2 h) – M4 and M6 threads, castors, painting, and finally a check of the cylinder straps and wheels.

On 2 mm sheet, tack closely and lay short runs alternately on opposite sides of the part so that the heat spreads evenly. Measure the diagonals after tacking, and again after welding the first side.

After welding comes the finishing: cleaning the welds with a wire brush, cutting the threads, and painting with a primer and a top coat. Do not skip the primer. A cart usually lives in a garage or a workshop where damp is common, and uncoated non-alloy steel corrodes.

When a welding cart kit is the better choice

A kit has the edge when:

• you want the cart finished in a weekend rather than over several weeks of evenings,
• you have no press brake or band saw and do not want to pay for cutting individual parts,
• you want repeatable geometry and the option of a system tool wall with a grid for M5 fasteners,
• you want to be able to order a single part if you make a mistake; every part has a number and a CAD revision.

Your own plans have the edge when the cart has to suit an unusual welder, two large cylinders or a particular recess in your workshop. If you need a cart for a 50 l cylinder or for two gases, sizes L and XL are coming soon.

For the cylinder that will ride on the cart, see our guides on welding gas cylinder safety and shielding gas for MIG and TIG. If you go for the kit, what is in the box, the price and the full specification are on the welding cart S page.