Matthew Borgatti, a designer and fabricator, has created a novel new spot welder with the help of a 3D printer and a microwave oven.
Borgatti is an expert spot welder, having used them for years in metal shops where he worked as a metal fabricator and machinist. He has since gone on to create an independent fabrication and prototyping business that specialises in 3D printing and laser cutting.
Most people simply won’t have the tools at their disposal to make use of this ingenious hack and they’re better off just buying a spot welder. As a simple work of engineering, though, it’s hard not to admire Borgatti’s skills.
The machine took four days to build, even for someone of Borgatti’s obvious engineering prowess. It works by altering the output of the transformer for the high voltage pulse used in the magnetron from the microwave. Turning the primary and secondary coil produces the low voltage pulse that is required for the heat resistance. When the two materials are clamped together, the heated point welds the exact point they touch together, thanks to the increased resistance.
It’s clever science and allows for a precise spot weld. Is it science for its own sake? Perhaps, but it is still amazing technology.
Borgatti stripped the microwave, ran the transformer with a number of temporary circuits and then used SolidWorks to run computer models of a number of different potential iterations.
His plasma cutting skills came out to create the metal electrical pieces that form the core, together with 3D printed components. Borgatti then went back to the microwave for the wiring, circuitry, power cable and spade connectors.
After finalising the designs for the laser cut parts and cutting them out of the acrylic, he created the 3D printed components.
Having gone to all the trouble of creating his masterpiece, Borgatti has made his designs freely available on Thingiverse. So if you’re feeling brave and have an old microwave to hand then you might want to consider taking a crack at this.
Of course, it’s still going to be easier to buy a spot welder off the shelf.
Watch the video below to see how it's done, and if you want to have a go yourself you can even download the source files.