What kind of accuracy can one expect from older Starrett tools?

pstemari said:
Nice—Faber Castell? That flared end was intended as a pipe tamper.
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Interesting, I had no idea. He did smoke a pipe for a number of years though, so perhaps it did fulfil that purpose. As for the brand, I've looked all over it just now and there's nothing. No initial, not even a "Made in ...." . I'm quite sure though that it would be a European made product, that's where they were. Pre-war Sudetenland. I have a nice silver cigarette case of his as well, perhaps for another day.

Thanks for the interest, and the tip.

-frank
 
C-Bag said:
"What blows me away is no matter how many snugs and adapters I accumulate I still get stumped and don't have some odd size to do something".
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Over years and countries probably many hundreds of established tool companies...while Starrett, Brown & Sharpe, Lufkin and others competed, they also recognized good design and execution. So while they mimicked ideas, object size a proprietary element. So, a variety of brands necessitate variety of snugs, scriber clamps. Goes so far they generated what some call 'bastard threads'. Kind of. Manufactured assemblies need screws and fittings, ad infinitum. Being full house captive shops they made their own taps and dies too. SAE, USS, BSS, DIN were decades away. When designer X had a slim indicator body, little screws were mandatory, he specified sufficient thread depth and selected a functional pitch [TPI]
 
pontiac428 said:
A height gauge isn't a calibration item.
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Not trying to split hairs pontiac428, is it only vernier height gage that isn't? As there are dial and digital height gages too. I'll bet they need to be calibrated. But not sure.
 
C-Bag said:
Not trying to split hairs pontiac428, is it only vernier height gage that isn't? As there are dial and digital height gages too. I'll bet they need to be calibrated. But not sure.
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I'm probably the one splitting hairs, since I stewed my bones in ISO accreditations in the past and it altered my perceptions forever. Others may disagree, depending on background. I'm okay with either, but since you are inviting dialogue, I would say that this example is a zero verification, and not a calibration on a vernier instrument. A dial instrument would have a zero verification and a range check, to ensure the response is accurate, but since you cannot change anything on a caliper or height gauge other than the zero point, it is not a true calibration. A true calibration requires slope and intercept adjustability across a minimum of two points. A zero is an intercept adjustment, and tuning the response across two points requires adjusting the slope. No matter how many intervals you check in a caliper, you are never able to change slope, so an annual "calibration" on those instruments is correctly called a "calibration verification". Lots of mincing terms, and often we know what one another means regardless, so it makes no difference in the real world.
 
Thanks. Metrology IS a very deep subject and it seems it is all splitting hair after hair. But your explanation makes sense and I appreciate it.
 
mikey said:
Yeah, well, I don't think mechanical drawing is taught in school anymore. So many kids don't even know which way to turn a screw to tighten or loosen it, much less what a ratchet is or is for. Sad.
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A little story, true!
I was young, but not really mechanics/ machinists in my family, though several good DIYer's. In 6th grade, a book report was assigned from a biography. We all went in school library. naturally bulk went to familiar names, Lincoln, Washington, Columbus, etc. An OK student, seems I rarely used someone elses idea of linear process. Found myself at the 'A' shelves Adams, Anson....nope, nah, heck no, then 'B'. Balzac, Bessemer....
Found Curt Gentry's John M. Browning. Read entire book right off, and wheels spun. Sure, firearm aspect interested me, but not like his ability to visualize, translated into functioning mechanisms. Not only inventor and tool grade machinist, but fully developed gunsmith educated by his father. No way I realized job of machinist was until that day. I do remember typical questions of kids "what do you want to be, when you grow up?". Didn't know before, and never fireman/ policeman/ doctor. Figuratively, next day asked that, a ready answer "Toolmaker!" Toolmaker, what's that?
Lol.
Started with hand tools, most birthdays etc, gifts often included additional tools. Upon collecting stones and Swiss files I was gunsmithing triggers. I still think real gunsmiths might be ultimate toolmakers. If you don't know firearms, I'm certain that makes no sense. Look up Collath Drilling, history of Beretta family, Frank Pachmayr, Roy Weatherby, German immigrant gunsmiths of Pennsylvania...
Blew through middle school shop classes, dying for real vocational class work. Finally, High School! Met prerequisites by Drafting, drawing stuff we assembled in Auto Shop. That planted me in Machine Shop, doing operations that could make - what we bolted together- that we knew inside out by drawing - all hinged to things like tolerance, hardware, tooling, materials.
By Junior year, two of us were selected for lab and lecture classes at the local college.
Nothing boils me over like depredation of vocational education. So I do some mentoring. I recommend FIRST Robotics. Incredible program.
Recently a school teacher tried telling me, "kids need tech to succeed.".
"Really?" Held my hand out, "gimme your phone". "Tell me Christine, how did this get into your hands?". [my favorite lure]
Same as a student "Bought it, local phone store!" [hooked, Lol]
"Hmmmph" "OK how did it get THERE?".
Puzzled look. [believe me, I've seen this a zillion times]
Right off 'tech' is horribly overused term. Just a lazy way to say 'I dunno how it's made'.
She gathers students and we spend an hour plus, talking about manufacturing, from poor little assemblers to micro level inspectors. A couple say they like "How It's Made". Well, that is a tiny fraction of what it takes to make it.
The hour is ending, I ask "any questions?". "Do you think we've covered e-v-e-r-y aspect her phone in her hand now?". Pretty enthused response that HAS to be everything, doesn't it? Enthused, or just anxious to leave, lol.
"Nope, didn't somebody build the delivery truck?

I'm adamant, a truly functional economy thrives on manufacturing. It's not really possible, finding the root of many products. There is a poster, text voices the paymaster, holding wads of cash, "Money going into your pay envelopes, to buy things you want; made by someone else, who needs our machines to make them. Etc."
After first 3 years US Navy, answered ad for a mold maker. Never a broom dude for any shop. New man, yes but never as apprentice. Worked tools in just about every facet of industry, used everywhere humans go.

Sorry. Not so little story, but true!
 
C-Bag said:
Not trying to split hairs pontiac428, is it only vernier height gage that isn't? As there are dial and digital height gages too. I'll bet they need to be calibrated. But not sure.
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Trend quite some time, at inspection, been to avoid interpretive measuring, for digital readouts. Calibration Exempt rarely means 'reliability assured'. These days; exempt is 'we don't know how', and 'customers coming in can't even read it'.
But, everyone's all about quality. As if.

Administration and piles of documents are marketing ploy of 'Assurance'.
Companies are pressed to hire non-productive shufflers to maintain records, increased costs.
Quality at the surface plate [ie] Final Inspection is past tense, usually too late. Unless supplied wrong drawing, nobody has a honest method to bill rework as receivable. But accountants can formulate Toolmakers as overhead.
 
Toolmaker51 said:
Sorry. Not so little story, but true!
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Fascinating story, TM, thanks for sharing. You seemed to have found your passion early in life and have clearly maintained it. Around here, you're preaching to the choir because we'll just about all agree with you.

I would raise one point, however, and that is that the world has changed. Nowadays, kids DO need tech to succeed. You do not need to know how a phone or computer is made in order to use it and modern kids in today's job market are at a disadvantage if they can't use them. How something is made is of no concern to many of them as long as it works. If you want to work for Google or Facebook or somewhere in the tech industry then you best know how to work with tech or you cannot compete. And you're right. A factory had to build those phones or computers but it took a geek with a computer to design the thing that had to be made by that factory so ...

I recently visited the NASA campus and met some amazing young people there. These are the ultimate tech geeks who not only fully utilize tech stuff but they also use it to build some of the most amazing devices - lunar and Mars rovers, etc. Their 3-D lab has a Bridgeport sitting right next to two 3-D printers. One of their engineers designed and built, BUILT, the miniature lithium batteries that go into a GPS tracker that is strapped to the back of an endangered bird to better understand their movements. I saw so many examples of amazing tech that they built that I can't remember them all. And it was mostly done by young tech heads with a passion for innovation that left me almost speechless.

The way I see it, manufacturing and tech go hand in hand. One builds what the other designs and innovates. Neither can do without the other, and the world is what it is because of this.
 
I have a set of 3, older vernier Starrett mics that I use quite a bit. Most recently, I had to make a alignment spud that would hold a compensator on a threaded barrel until the red loctite had set.

One thou too small and the comp would be able to tilt such that a bullet could strike a septum on the way out, diminishing the accuracy at the very least, to blowing the comp off the pistol worst case.

For something like that I work to about a half thou, and my old(er) Starretts work just fine for that. :)
 
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