Old timer told me to ditch my digital caliper for a steel ruler and I thought he was nuts

I had this senior drafter named Walt lean over my shoulder about 6 months ago and say something like "that digital thing is lying to you, kid." I laughed it off because my Mitutoyo caliper was reading to 0.01mm perfectly fine. Then I did a tolerance stack on a motor mount plate and my parts kept coming back with a 0.3mm interference. Swore my caliper was right. Finally caved and checked with his old steel ruler and a loupe - the caliper was off by about 0.15mm from a dead battery and I never noticed. Has anyone else had a long trusted tool suddenly screw them on a critical dimension?

3 comments

3 Comments

lucasjackson21d ago

Trusting a tool you've used forever without checking it is like trusting your car's gas gauge when it's stuck on half a tank. Happens all the time with all kinds of stuff, not just calipers. Gotta double check the basics every now and then.

henderson.oscar21d ago

You know what's funny? I used to be the exact same way. I had this old dial indicator on my surface plate that I swore was dead on, I'd been using it for years without a second thought. Then one day I was checking some brass spacers and everything was coming out 0.1mm over. I spent an hour blaming the material, the temperature, the phase of the moon. Finally I grabbed a fresh gage block and checked the indicator. It was sticking at one spot in the travel, probably some old oil turned to glue inside. I felt like an absolute idiot. Now I make it a habit to zero check my tools against something known every week, it saves me from those embarrassing moments where you're dead wrong but acting like you're dead right.

logan23617d ago

Respectfully, I see it a little different. If a tool has been reliable for years and you've maintained it properly, you can usually trust it a lot more than something fresh out of the box these days.