Did You Actually Want Those Tolerances To Stack Like That Or...

Engineers watching non-engineers encounter GD&T (Geometric Dimensioning and Tolerancing) is like watching someone play UNO for the first time. "Draw 25 cards or explain datum reference frames" might as well be written in hieroglyphics. The look of pure defeat when someone realizes their perfectly designed part won't fit because they ignored stackup tolerances is a special kind of schadenfreude. Manufacturing engineers have been dining out on these mistakes since the industrial revolution. Nothing says "I should have paid attention in engineering class" quite like realizing your 0.005mm tolerance just turned into a 0.5mm disaster.