2026-01-19

Last modified: 2026-01-19 14:06:40

• Tractor
• Welding

Tractor

Plan is to finish assembling it, brush-paint the remaining black parts, and maybe paint a yellow stripe or something on the bonnet. And then it's done.

Still needs the yellow stripe but I may just leave it, too much faff.

Welding

I need to get better at welding because lately my welds have been absolutely awful.

I did a bunch of messing about on a piece of 3mm steel plate:

What I have learned is that my mental model was completely wrong!

The welder has a knob for voltage and a knob for wire feed rate. I was thinking of voltage as a temperature correlate and wire feed as a feed rate, and treating it like a 3d printer extruder. But it doesn't work like that at all.

In fact the wire feed rate controls temperature much more strongly than the voltage does. And the voltage controls "height" vs "width" much more strongly than wire feed rate! So it's almost the exact opposite of what I thought.

If you want it hotter, increase the wire feed rate. If you want it flatter, increase the voltage. That's it.

So although the welds on that plate are not magnificent, they are at least beads rather than a spattery mess, and I now know how to control the machine. So hopefully the welds on the car will be a bit better than the welds on the tractor.

Mostly I used voltage modes 4 and 5. I didn't try 6. And I used the entire range of wire feed speeds.

It tripped the breaker once, and I don't know what exactly causes it. I was on heat setting 3 and low wire feed speed and tripped immediately, as soon as the wire touched the metal after I squeezed the trigger. I flipped it back on and did exactly the same thing again and it was fine.

But you'd think that the lower voltage and lower wire feed would put less demand on the breaker, so why did it trip? Just random I guess. Probably it is on the verge of tripping every time I create the arc, and sometimes it does and sometimes it doesn't.