My tools permit the use of any preferred units, determined by the units nominated in the active rhino document.
As noted, these scripts presume metres, so if you’ve opened the script with a rhino document of millimetres, then as you determined you need to scale the lengths.
For the soap file model, there is a section property diameter that is not so obvious, and if you don’t adjust this the sensitivity of the form finding properties means the model won’t converge. You also need to ensure the settlement vector is scaled or it will move the corner points down 2mm (which would appear flat).
I’ve attached the three scripts below set to work with mm.
Cheers,
Jon
180604 normal properties.gh (24.2 KB)
180604 soap film.gh (40.5 KB)
180604 force density.gh (28.7 KB)