DIY Spot Welder (Super Scary Weldy Thingy)

thingiverse

This build is quite complex but should be within the capabilities of makers who are interested in 3D printing, metal casting, metal machining, and general fabrication. It makes use of a re-purposed microwave oven transformer as a power source and some ancillary electrical parts 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 a few switches. I have included ready 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 drawings. I have tested the machine and it is capable of welding steel and stainless steel although the spot size has to be kept small (approx <2mm) to maintain the current density. It is worth checking out Youtube to research the methods used to rewind the transformer. Be warned though, this machine uses mains voltage and should only be attempted by those who are confident working with high voltage/high current electricity.