Drafting Machine Scales

Hi everyone,

My boyfriend is a carpenter and has shown interest in hand drawing his plans rather than using CAD for all of them. We found a video of a man using a drafting machine and he's quickly become obsessed.

I've found a ISIS and a Kuhlmann drafting machine with the arm online but neither come with the scales. Really struggling to find the scales online - does anyone know wether you can DIY them with a standard scale ruler. Or any option?

Any help would be greatly appreciates...

Drafting Machine Scales