I used strips of 2.5mm Balsa wood

I fashioned a handle of masking tape on the stanly blade to reduce stress on fingers

Align metal ruler with balsa strip

since I'm using a 1:50 scale I am cutting 2500 meters it's about 10 cm

Make a assembly line and don't mix your sizes

Test your sizes

I used a special UHO but you can use the regular works fine

Final frame design

Another example

This is a early model of our bridge in the design stages Balsa is fast a simple to use Go Try it !

I also used it as a molding material but that will be another guide ;)