Why do I always get the impression with DIY builds that anything suggesting a welded frame is a leap in the dark.

By welding I'm suggesting a steel tube build and a fully welded one at that......no bolts or screws etc.

Here's an example of a build material you can rely on for rigidity and pure strength...……..square steel tubing...….100mm X 50mm X 6mm wall thickness, and it won't break the bank if you buy a full length and get it cut to the sizes you want.

When it comes to welding all you really need for a half decent welding bead, even if you've never done welding before, is a cheap hobby 120 amp welder and couple of hours with some scrap material and a few welding rods.....avoid Mig welding unless you have more funds for the outlay.

Of course, most people want to run before they can walk with a Killa Dilla machine that outperforms all comers bar none, but an amateurish finish on a welded job can be ground up to look good and paint covers all sins......the main criteria is to make it as square as possible to all axes and correct your mistakes as you progress.

So far I don't think a work envelope has been mentioned or the type of work intended for a build...…..but KISS at all costs.
Ian.