Welding a home: the steel frame, week one
Forty metres of box section, a second-hand MIG welder, and the discovery that my garage floor is nowhere near level.
The plan is a custom steel-frame mobile trailer — small enough to tow with what I already own, strong enough that I never think about the chassis again. Week one was supposed to be the easy week.
The floor lied to me
I squared the first three rails, tacked them, and found an 11 mm drop across two metres of what I had assumed was a flat concrete slab. Every measurement I had taken up to that point was quietly wrong.
The fix was four adjustable stands and a laser level, and half a day I had not budgeted. The lesson was that on a build like this, the reference surface is the first thing you build, not the thing you assume.
What went right
- 50 × 50 × 3 mm box section for the main rails — heavier than the calculator said, and I have zero regrets
- Full penetration on the corner joints, ground back flush
- Every cut dry-fitted and clamped before a single tack
- Frame squared to within 2 mm across the diagonals
Measure twice is optimistic advice. Measure twice, clamp, then measure the diagonals.
Next
Axle mounting points and the suspension pickup. This is the part where the maths stops being about aesthetics and starts being about whether the thing stays attached to my car at 60 mph.