People blindly trust cmms for some reason. Perhaps because a computer spits out the numbers.
A 3-D gauging system is full of little errors that add up and make for lots of sleepless nights for the designer.
Bob
Ouch... There is a reason, it's money. I hope this doesn't make you sick - but you'll know in your heart it's true, as I did.
A friend of mine recently retired & we had a chance for a conversation. We had worked & crossed paths a number of times over 40+ years and I count him as one who has "good game".
In the conversation he recalled a time shortly before OMC closed in Galesburg, where he had a bit of a run-in with a CMM. He went with the last of the toolroom because he'd still do the reamer sharpening & such by hand against the finger (those who know this, know it - those who don't - please don't speak) all the wannabes & the feather bedders left the toolroom early.
They had a CMM with little to do, so - tools were sent up to qually... He got called up on a tool# that was out of spec. He gathered a mic & gage stack and went there (it was an even tooth multi-fluted tool).
The person showed him the report & the results from the inspection (looked like a store receipt back in those days). He measures the stack with the mic & measures the cutter & says I'm good by this - see what you get because I don't know what's going on.
The response from the inspector was... "I don't know how to use a mic"...
He said "could you run that again for me?". He did & it wasn't the same but was still out of spec (a bit less). Ron said "I don't know how to run your machine, but I think you're gonna have to learn to run a tool & cutter grinder because you have my best" & walked out - nearly left the craft but came back a few years later in a different place.
About the messaging of the linear math (base 2, 10, 16 etc) vs angle of rotation - they are different bases & often come up with very inconvenient ratios that "will not" reduce for better precision but only "scale up" for "basic" solution. So - when someone says "if you can't find a number between two numbers so there is no number, and they are the same" it's for algebra & number manipulation to get some solution, it is not always a "count to the integer solution".
I'm really tired now,
Matt