I made a perfect working spot welder with MOSFET switch. Easy to build and cheap.
Here is the tutorial:
Part 1: https://www.youtube.com/watch?v=VSGhcC35Z6Q
Part 2: https://www.youtube.com/watch?v=o6OafhgeK_U
I also ordered a batterybox from aliexpress for 45$ for my Li-ion cells. Want to...