Spot welder machine

Do it yourself

Spot welder / do it yourself
Spot welder / do it yourself
  1. Single and double pulse cell spot welder, made of a transformer from an old microwave oven.

  2. Controlled by Arduino nano microcontroller.

  3. The whole built on an old drill stand.

  4. Copper wire electrodes attached to swinging aluminum arms. Each arm bends independently, thanks to which level out unevenness and the electrodes are pressed against the welded tape with equal force.

  5. With swinging arms, a limit switch is installed, which automatically activates the welding pulse when the electrodes are pressed against the cell.

    The whole is operated comfortably with one hand, so that with the other hand we can hold the cells or tape 😜.


PCB design, diagram in eagle and code in Arduino IDE to download

When designing the welding machine, I used posts from the electrode forum


Advice for builders:

Place the controll electronics at least 30cm from the transformer.

At the beginning I fitted everything, including the controller and transformer, into the housing from the ATX computer power supply. Unfortunately, this was not a good idea, because the magnetic field from the transformer generated interference and badly affected the micro-controller. The effect was that sometimes during welding the welding pulse did not disappear !!! Copper wire electrodes were evaporating at that moment, and there was a big hole in the tape ….

After moving the controller to the top of the welding machine (to the top of the drill stand – this can be seen in the first photo and in the film about welding the battery) everything is OK.


When etching the PCB from my project to refresh the PCB in Eagle with the “Ratsnest” function, so that GND mass polygons appear!


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