DIY Spot Welder (Super Scary Weldy Thingy)

thingiverse

This build is quite intricate but should be well within reach of makers who have an interest in 3D printing, metal casting, metal machining, and general fabrication. It leverages a repurposed microwave oven transformer as its power source, along with some auxiliary electrical components such as a DC power supply for switching the transformer via a solid-state relay, a digital timer for setting the weld interval, a salvaged DC cooling fan from a PC, and several switches. I have included pre-made STL files for all the casting patterns, as well as STEP files of the complete design. Both 2D and 3D drawings are available for the engineering diagrams. I have thoroughly tested the machine and it is capable of welding steel and stainless steel although the spot size has to be kept small (approximately less than 2mm) to maintain the current density. It's worth checking out YouTube to research the methods used to rewind the transformer. Be warned, however, this machine uses mains voltage and should only be attempted by those who are confident working with high-voltage/high-current electricity.