I design test rigs and drivetrain prototypes, and I have carried 9 of them from first sketch to working hardware over 11 years. My current work at Officine Vetra cut gearbox validation time from 6 weeks to 9 days. I still draw every first concept by hand before it touches CAD, which my colleagues tolerate with patience.
Wheel A turns crank B, which raises spar C through a quarter arc. The reader will note the ratio of 26:14 between the wheels; the author keeps the same habit in modern work, where every drivetrain begins as a plate like this one before any metal is cut.
chi disegna prima, ripara meno