My primary goal for this part was to provide a flat surface for an MDF baseboard. My secondary goal was to create a stiff structure.
It didn’t turn out well enough to be usable. The height of the side panels was different by 0.03” - 0.05”. They were also visibly arched at the center, which was due to the sheet changing distance from the plasma torch. My workholding was ineffective (actually nonexistent) and I was unwilling to put any effort into this because I didn’t understand how the plasma torch works. And besides, the cutting slats are really disgusting!
Thought Process
I wanted to use the plasma machine to cut out interlocking templates, then I could spot weld everything together without using a jig. The cut would wave up and down within the width of the bed but when you put a piece of MDF across it, it would be fine.
Faulty Assumptions
Making parts out of metal is the exact same thing as making them out of wood, except stronger, and you also have to weld them together at the end.
It’s hard to make two rectangular parts lie parallel, but if you cut out all the screw holes in the computer and get the tolerances right, then the parts will be close enough. And plus, you won’t have to measure them or adjust anything.
Conclusion
Going back to the beginning, I still needed a thing to solve the problem. After thinking about it really hard, nothing bad has ever happened to me due to wood changing moisture content. (Except for that one time I didn’t have a bottle opener and a piece of cork fell into my wine bottle.)
Given that, plus my very limited experience working with metal, I decided to bolt everything to an MDF baseboard in the interim. This project was a good learning experience, which is the euphemism for a debacle. I was forced to confront my own attitudes towards surface preparation and measuring things, and this will influence my approach moving forward.
