Find all your DIY electronics in the MakerShed. 3D Printing, Kits, Arduino, Raspberry Pi, Books & more!
welma2000.jpg

The folks at the Italian site Modellismo Hobby Media sent us this email:

During the Spielwarenmesse (German toy fair) the model company ROBBE showed the WELMA 2000: a tool supposed to be the World’s smallest electronic spot-welding device.

This electronic spot-welding device has been specially developed for producing assemblies from steel wire. The point where the wires meet is fixed together using a pair of pliers whose tips take the form of welding contacts; when the start switch is pressed, the joint is firmly welded together.

During the welding process a current of up to 2500 A flows through the contacts for a few thousands of a second.

The WELMA 2000 will sell for 124 Euros (about US$157). No word on availability in the US.

Welma 2000

Gareth Branwyn

Gareth Branwyn is a freelancer writer and the former Editorial Director of Maker Media. He is the author or editor of a dozen books on technology, DIY, and geek culture, including the first book about the web (Mosaic Quick Tour) and the Absolute Beginner’s Guide to Building Robots. He is currently working on a best-of collection of his writing, called Borg Like Me.


Related

Comments

  1. Timm Murray says:

    Is that a model train transformer hooked up to some needle nose pliers?

    Time for a remake?

  2. gear head says:

    I’m sorry, 2500 amps?

  3. craig says:

    For $175 to $200 you can buy a wire feed flux core 115VAC welder with 4 settings. You can tack weld thin sheet metal, or run thick heavy beads along 1/4″ steel with ease.

  4. Jef T says:

    Yes, 2500 Amps is possible, when a capacitor is discharged through a short circuit. It’s just a short peak.
    Discharge time = 1ms
    Internal cap = 100000 uF
    Charge voltage = 25 V

    I = dV/dt * C = 25 / 1m * 100m = 2500 A !

    Of course, a good electrical contact is required, otherwise the current will be limited by the contact resistance.

    So probably it’s just a capacitor in a box, charged by a transformer…

  5. mikey says:

    You could make some radical sculptures out of paper clips with it, though.

  6. i says:

    gear head, yeah, those don’t look like 2500 A cables to me either. Wikipedia says “real” spot welders use 4000 – 25000 A, but those have big solid copper electrodes carrying the current to the workpiece.

    Anyway, some more info from the manufacturer’s site: They intend the device to be used with 1mm stainless steel wire to make things like railings for model ships. Here’s a slightly blurry picture of the results http://www.welma2000.de/content/images/0247e2de7ff28f7b037efefd380f475a.jpg

    Jef T, “capacitor in a box, charged by a transformer” sounds like an easy re-make, but the “start switch” would be tricky – how do you switch on a 2500 A load? Are there mechanical switches that can handle this without welding their own contacts together?

  7. Tyrone says:

    Would anyone know if it would be practical to have one of these units with a maximum input power requirement of 115 VAC/10 AMPS. This would be for welding 1/16 inch. maxmimum steel wire.

  8. Jade Harker says:

    Please share more information on how to use, features and many more.

  9. aczez says:

    Just ordered one directly from Robbe, will write a short review when i receive it.

    1. Gareth Branwyn says:

      Oh, we would LOVE to post a review of this on the site. Please do let us know when you get it/review it.

  10. Gautham says:

    Has this been reviewed anywhere yet? Cant find much about it on the web…