Measuring and Modelling

Once I'd got the interior stripped I measured the entire interior space of the trailer along all three axes, including noting exactly where the windows, skylights, and any other immovable constraints were, along with the exact curvature of the panels in all directions.

This took a number of tools: a tape measure obviously, but also a laser pointer, an ingenious tool that allows you to capture the shape of an exact curve and a scribing tool that allows you to map a curve onto a piece of cardboard.

After plenty of double and triple checking I used these measurements as a basis for making an exact model of the interior in CAD which has proved invaluable for experimenting with different ideas at low cost as well as designing parts that need to be millimeter perfect.

Well, I say that, the model and measurements aren't millimeter perfect everywhere. But I'd say overall it's accurate to within 3-4 millimeters which is sufficient to figure out where to put the toilet or cooker for example.