It used to be difficult to dump enough electricity through two pieces of metal to fuse them together. But a lithium-ion battery can do it. The question is, is it necessary? [The Signal Path] takes apart a cheap battery-based spot welder to see what’s inside and tries to answer that question. You can see the teardown in the video below.
The cheap welder has some obvious safety issues so the first was to cut some wires and also re-tin some of the PCB tracks to make sure they have the lowest possible resistance. Of course, the less resistance in the wiring, the more current is available for welding.
The welder did a good job attaching a metal strip to a battery. After a successful weld, the video shows how to measure the current using a clamp meter with an enable function. The resulting pulse was 960 amps, although it immediately drops over the 50 millisecond pulse, but still impressive.
The security issues were worrisome, but easy enough to fix and we recommend doing the same research if you buy one. Some commenters said their version of similar welders didn’t have the same issues, but it’s worth checking before you burn down your shop.
We’ve had our own concerns about cheap spot welders before. This isn’t the first piece of cheap gear we’ve seen that went through a safety inspection before first use.
This post Cheap disassembly of the spot welding machine | hackaday
was original published at “https://hackaday.com/2022/03/16/cheap-spot-welder-teardown/”