If you move in certain shady circles, you may have noticed the crop of improbably cheap “pocket welders” popping up on the market these days. They’re all variations on a theme, most with wildly optimistic specs minimal accessories of the lowest possible quality. But their tiny size and matching price make them irresistible to the would-be welder, as well as attractive to hardware hackers.
With a 220-V outlet in the garage waiting to be filled and well-knowing the risks, [Mr. RC-Cam] purchased one of these diminutive welding machines. Its shortcomings were immediately apparent, and a complete rework of the welder was undertaken. After addressing safety issues like the lack of a ground connection, [Mr. RC-Cam] added a color-matched 3D-printed hood to house a fancy new LCD touchscreen display. Backing that up is an ESP32 with Bluetooth, which supports remote control via a key fob. He also added a current sense board that uses the welder’s current shunt to measure welding current. Expediently calibrated using a waffle iron and a milli-ohmmeter, the sensor showed that the 200A max advertised for the welder was more like 100A. He tried adding some big electrolytics to fix the current issues, but no dice. With a decent stinger and ground clamp, the modified welder is good enough for his needs, and much was learned in the process. We call that a hacking win.
As an aside, [This Old Tony] recently did a review on a similar welder if you want more details on the internals. We also covered the conversion of a buzz-box to a TIG welder recently, should that be more your style.