An old machinist at a shop in Pittsburgh taught me a trick about blueprints I still use

I was in Pittsburgh for a job last spring and stopped at this tiny machine shop to ask about a weird tolerance on a print. Old guy named Joe, must have been 70, looked at it for 2 seconds and said "that's just a drafting error, kid, measure from the corner instead." He walked me over to his ancient drafting table and showed me how to rescale the whole thing by hand using a pair of dividers. I had been staring at that print for an hour and he solved it in 5 minutes flat. Has anyone else run into someone who just made drafting click for you in a weird way?

2 comments

2 Comments

baker.simon23d agoTop Commenter

Yeah but @matthewross, is it really "trusting your gut" or is it just experience telling you when the paper's lying? Joe still checked his fix against the other dimensions before he made a mark, so it's more about knowing what questions to ask than ignoring the print. That divider trick works because it catches errors the drafter made, not because you're guessing.

matthewross23d ago

I used to be one of those guys who thought if it was on the print it had to be right, but Joe would have laughed me out of the shop. Seeing him just grab those dividers and fix it without a second thought made me realize how much of this trade is about knowing when to trust your gut over the paper. That kind of experience can't be taught in a book, it's just something you pick up from people who've been doing it since before CAD existed.