🎨 Garden Shed: Full frame

4th January 2021

Today, in a mammoth 12-hour session, we finished the frame! By the end of the day we had the frame mounted on the trailer and it turned out nice and rigid.

A couple of themes have been emerging over the course of this project. The first is distortion management. It was very obvious how distortion was affecting our structure as we welded it. I think it will all be within the tolerances of what we can work within, and it was also partially corrected as we joined the full frame together; each part helps hold the others in the correct shape.

I'd like to build up a better vocabulary for these techniques. At one point we had a rectangular section that was out of square. We used a ratchet strap to bring it past square in the opposite direction and then added some bracing, with the idea that the tension pulling it out of square would be counteracted by the out-of-square-in-the-opposite-direction bracing and leave the structure sitting square. At the end of the day it snapped back a little too far, so it seems that there's a process to get our eye in for how to pull this one off. I've worked with a very experienced metalworker in the past who used this principle but didn't nail the exact over-correction required, so I gather that it's a difficult process to get dead on.

The other thing I've been working on has been to get neat and strong results with vertical welds. This project gave the opportunity to work on almost every out-of-position weld, while working at the top of the ladder at the limits of the reach of the welder. It was a great challenge, and I think the only weld I'm struggling with at the moment are vertical-ups. I used a lot more vertical down welds (where we had a light-gauge join) than I have in the past, and got a lot neater results. And I got some improved results on vertical up welds using an upside-down V weave moving a lot more rapidly than I've tried in the past - probably a V and back every second. Any slower and the weld pool would start to puddle out, so I think I might have a more manageable situation using a lower voltage, too.