> [!tldr] The sum of bands of uncertainty A tolerance stackup is what you get when you get when you join several pieces together, each of which has its own tolerance, and those tolerance [[Errors add, not cancel]]. Sometimes you get lucky and the slightly too short things get paired up with the slightly too long ones and you end up with something that's "about right"... but often you're unlucky and the tolerances stack up unfavorably. This note was pulled out of my note on [[Tolerance stackups are easier with fewer things on the stack]]. I realized the first full paragraph was just defining the term for readers. I guess I'm writing for readers now. Hi reader. **** # More ## Source - self