Used extensively in the automobile manufacturing industry for constructing the bodywork, spot welding is also seen in other various situations, like building PC cases or battery cells. A spot welder has the advantage of precise welding point and only heating the welding spot, so the rest of the materials remain cool and can be managed easily. Of course most of the welding done in an industrial environment is automated, but sometimes you may find yourself in need of a spot welder for personal use. Here’s how you can build one yourself using a microwave oven transformer.
The device uses two 4 feet heavy gauge copper wires to connect the transformer to the welder tips, a 12″ 2×6 wooden platform that acts as the base of the , two 7″ 2×2 wooden pieces which act as the “jaws” (only theÂ upper one is mobile), two corner braces to align and hold the welder’s jaws, two lugs which connect the copper wires to the welding tips and a bunch of screws. Care must be taken in aligning the mig welding tips to the right position, cutting the cooper cables to the right length and in stripping and mounting the welding lugs. The welder does not rely on high voltage, but on high current instead. After assembling all the parts, you should check electrical parameters with a multimeter.
With a fairly simple design and part list, this is a spot welder intended for small, personal projects like electrolysis cells or small robotic platforms. Remember to take precautions when handling such a device, as it uses high currents and generates high temperatures. You can find a detailed step-by-step presentation of the spot welder in the link below.
DIY Spot Welder: [Link]