3D Spot Welder

Spot weld metal wire to a surface to create 3D objects.

Public Chat
Similar projects worth following
In this project I want to build a machine which spot welds metal wire to a surface to create metal objects like 3D prints.

A short test of my MOT spot welder which will soon be replaced by a capacitor based spot welder.

The 3D Spot Welder will consist of four main parts:

- The machine frame and gantry system

-  A spot welder power source

- A spring loaded spool of metal wire

- A alignable toolhead with one spring loaded spot welding electrode and an idler wheel which will be automatically aligned to the moving direction while moving.

  • MOT Spot Welder

    Dominik Meffert01/13/2020 at 01:26 0 comments

    I have built a Microwave Oven Transformer Spot Welder from an old microwave tansformer, a jump start car cable and some parts I had laying around.

    It works so far but the circut breaker tripped randomly all 5 welds or so and the connection

    was not really stable.

    Another test with different wire and one electrode clamped to the surface. This time the weld quality was better and the connection was very strong. But until now the wire does not welt to the surface.

    I tested again with the first wire type and it worked like the other, it seems like the one electrode placed on the surface and the other placed at the material makes the difference.

    Instead of welding the wire to a piece of sheet metal I tried to weld it to a piece of wire fence and it worked. The fence is also a lot cheaper than sheet metal and can be easily cut off after the object is finished. This fence has a 13*13mm mesh but I think for automatic welding it should be denser.


    I actually wanted to build a capacitor based welder but I have read that if the capacitor gets shorted it will not last for long...

    So I solved the circuit breaker tripping issue by connecting five 4 ohm 100W resistors in series with the transformer primary winding. Doing so it should limit the current to around 11.5A. I did a short test and after 10 welds the resistors get barely warm. They will be mounted on a heatsink for a long duration test to see whether they can work in continous operation.

  • Getting started

    Dominik Meffert01/10/2020 at 13:44 0 comments

    I started this project because I am searching for a way to create 3D metal parts.

    I actually wanted to build something like (,

    but because they have a patent for it and I don't want to get sued I must try something different that is simple and can be used by everyone like spot welding.

    I hope that I can create 3D spot welded wire parts which are made of metal and a bit stronger than FDM printed parts.

    The first thing I want to do is building a DIY spot welding machine from the internet to getting started.

View all 2 project logs

Enjoy this project?



Dan Maloney wrote 6 days ago point

I really like this idea. I can see it starting out really simple, with wires tacked to the build plate to make "low poly" shapes. Then you increase the number of spot welds to improve the resolution, and then build up layers. Really cool idea.

One place you might have trouble is the duty cycle of your spot welder. You might have to build a pretty beefy welder to keep it more or less continually operating.

Good luck, and keep us posted.

  Are you sure? yes | no

Dominik Meffert wrote 6 days ago point

Thank you,

I hope I can build a capacitor based spot welder that can work for hours, like a 3D printer. Maybe with multiple capacitors to switch between them for reducing time between two welds and for using double pulse spot welding if needed.

  Are you sure? yes | no

Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates