Wheel ruler - video

[Toolmaker51]

Age of an object has little to do with utility, nothing new under the sun notwithstanding. Greeks and Romans used measuring wheels, before GPS at least a third of European drivers had a map reading opisometer. Naval architects, surveyors and bill of material schedulers use them today. It's all about the increments.
This is a terrific demonstration of design and somewhat intricate processes, in a CNC router. A machine I'd never before considered worth adding to my shop.
Neither K&T Rotary Head or 2 axis CNC; sufficiently agile for compound engraving. The processes themselves were watchable, the finished product is professional.
Compared to fidget spinners and live models that have no useful ability, this is superior.