You’re a good bloke Crayon, I appreciate chatting with you. I’ll read the links you sent shortly.Be certain of the uncertainty.
Here's just one example of an "uncertainty budget" from the Mitutoyo article below (these figures don't apply in all cases, but these are some of the kinds of things we are talking about):
https://www.mmsonline.com/articles/understanding-errors-in-hand-held-measuring-instruments
https://www.mitutoyo.com/news/resource-center/on-measurement-uncertainty/
Tom, maybe you need to bin your fancy new micrometer and get yourself a scanning tunnelling electron microscope. There might be an atom out of place on your bearing race! J/K
If you really want to get into this kind of thing, I suspect that "understanding the errors, where they come from, and how to minimize them" is more important than the quality of the instrumentation.
There are also some good forums for machinists out there on the web where I'm sure they'd be happy to discuss this kind of topic for weeks on end...best of luck with your new instrument!
Thanks for the kind words, I appreciate you saying so. They are some beautiful tools you have there.I appreciate that Tom strives to do the best he can in his repairs, and teaching himself/learning new skills. He's been a good teacher here.
I really don't like the new digital measuring tools. Too much to go wrong and break. Also, they have dumbed down the people using them (not an insult to Tom). Plus, if you get one wet with water or solvent, or drop it, chance's are much better that it breaks than a mechanical one.
I'll say the same with scales, beam balance vs digital scale. I've seen the restored beam balance used in the 1800s to determine the atomic/molecular mass of hydrogen vs oxygen.
For saws I'm happy for most work with +/- 0.001" 0.025 mm. Verniers do this fine, otherwise I'd use a quality micrometer.
I have 3 calipers: 1) A cheap plastic dial caliper, one I use to tell things like what is the dia of a bolt, 2) a Brown and Sharpe 571 vernier caliper (the most robust), and 3) a Starrett 120 dial vernier (what I usually use). The B + S and Starrett both have nice wooden cases, and are old USA made ones.
There is more that can go wrong (dial parts) with the Starrett, than the B + S, and it is no more accurate despite having a dial.
Starrett 120 - 12
View attachment 905383
I need reading glasses to use the Brown and Sharpe, but it is the most robust and foolproof (if I do my part), and it has the fine adjustment to "get the feel" correct when taking a measurement, and can then be locked before taking a reading. I like that fine screw adj. better than a wheel on a dial caliper. It has two scales on either side for inner vs outer measurements.
View attachment 905384
A link showing use of the B + S
Using B + S 571
P.S. I've got ~ $75 into the Starrett and B + S, I got used.
Same tools, but I took a screenshot for the post, so you could see what I'm talking aboutThanks for the kind words, I appreciate you saying so. They are some beautiful tools you have there.
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