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uncle pete
03-21-2012, 05:57 PM
Ok,
This is in no way a tool gloat or a "nice score" type of thread. That would be highly disrespectfu, And to be honest. I really can't think of something like this as a tool I now own. I'm more of a caretaker of it for now I guess.

Last month there was a post made by a gentleman in his early 80's showing a Sine Bar built by his long deceased friend on the Chaski forum. If my crap computer skills are correct? I'll attempt to put a link for it here. http://www,chaski.org/homemachinist/viewtopic.php?=4&t=92286 This link shows the pictures.

For some unknown to me reason, He thought my comments were enough to send it to me. He refused my buying it from him, A donation to any charity of his choice in his or his friend and builders name, Or even the mailing costs from Arizona to B.C.. He simply wanted it to be passed on to someone who would appreciate it's obvious craftsmanship, And the man who was skilled enough to build it to these accuracy levels.

I've read just enough about the Los Alamos site to have some ideas about what kind of accuracys were needed, And just how good you would have to be to even work there as a machinist or tool maker. Given that this was a fully funded and controlled government site. And the precision required to even do the work. Then logicly the equipment and methods used would have been to the highest accuracy standards, Actual costs would have been immaterial. The 60 year old hand drawn sketch done by the original builder was included with this sine bar. The inspectors exact measurements were also marked down in five decimal places. The center - center distance for the round rolls are given as 5.00034. There's a lot of members here with far more knowledge than mine. So I'm wondering if anyone here could give an example or at least a few thoughts about what would have been used to measure to these accuracy levels 60 years ago? Gage blocks accurate to within millionths have been around since the 1920s. I've yet to find out how those exact measurements were obtained.

I've also read that metal will change it's exact dimensions over time. Can anyone confirm that? And if so what direction it goes. Shrink, expand?

Given how pristine this tool is and it's age. I'd suspect it was built from hardened stainless and then precision ground. There's not a single tool mark left anywhere on this tool. In fact it makes my $300 Suburban built sine bar look a bit crude.

This has been one of the oddest, Yet nice at the same time things that have ever happened to me.

Oh yeah, Exactly what Los Alamos is or was, And why that site was needed or not isn't a issue that needs to be debated here. I'd like it if this didn't become a locked thread.

Pete

Crap, My Chaski link doesn't work. As of today it's in the general forum, Page 2 and towards the middle of the list. Thread title is "What is this".

gcude
03-21-2012, 06:08 PM
Your link has a typo. Here is the corrected link.

http://www.chaski.org/homemachinist/viewtopic.php?=4&t=92286

A very nice tool. I too am looking forward to the discussion here on this tool and the accuracy to which it was built all those years ago.

sasquatch
03-21-2012, 07:07 PM
Very good post and questions Pete, and congratulations on being the lucky recipient of this tool !!

oldtiffie
03-21-2012, 07:10 PM
The inspectors exact measurements were also marked down in five decimal places. The center - center distance for the round rolls are given as 5.00034.


I don't think that 5.00034" for a nominal 5.0000" is any big deal and is an error of 0.00034" which is about 3 1/3 "tenths" - almost "half a thou".

Many here can work to that order of magnitude of accuracy if needs be.

I'd be a bit less unimpressed (perhaps) if there was another "0" ie 5.000034 (about 1/3 of a "tenth") or two ie 5.0000034 (ie 3.4 "millionths" of an inch)

I'd like to see some one post a copy of a USA-made 5" sine bar inspection sheet/s for comparison.

By the time any errors on other parts of the sine bar were accumulated (taking into account all the +'s and -/s) the end result may be significant.

I'd be more impressed if the accuracy of the sine bar matched the accuracy of the "slip gauges" - Classes 0 (Laboratory), 1 (Inspection), or 2 ("Shop") - with which I'd expect that they'd be used.

Sorry to be the party pooper.

Not.

I'd like to hope that one or more "0"s were left out by the OP ie as a "typo". _O"

loply
03-21-2012, 07:44 PM
I don't think that 5.00034" for a nominal 5.0000" is any big deal and is an error of 0.00034" which is about 3 1/3 "tenths" - almost "half a thou".

Many here can work to that order of magnitude of accuracy if needs be.

I'd be a bit less unimpressed (perhaps) if there was another "0" ie 5.000034 (about 1/3 of a "tenth") or two ie 5.0000034 (ie 3.4 "millionths" of an inch)

I'd like to see some one post a copy of a USA-made 5" sine bar inspection sheet/s for comparison.

By the time any errors on other parts of the sine bar were accumulated (taking into account all the +'s and -/s) the end result may be significant.

I'd be more impressed if the accuracy of the sine bar matched the accuracy of the "slip gauges" - Classes 0 (Laboratory), 1 (Inspection), or 2 ("Shop") - with which I'd expect that they'd be used.

Sorry to be the party pooper.

Not.

I'd like to hope that one or more "0"s were left out by the OP ie as a "typo". _O"

With a sine bar the actual distance doesn't matter, the point is that the inspector was (apparently) able to measure to 5 decimal points, which allows the thing to be set accurately.

I have no idea what instrument or method was used in the measurement.

jkilroy
03-21-2012, 07:57 PM
That is a fine piece of work. I have several tool maker made pieces, a couple of sine bars, angle blocks and the like. I also feel like I am just a caretaker and hopefully I can find a suitable recipient when the time comes.

uncle pete
03-21-2012, 08:05 PM
Loply, jkilroy,
Exactly correct. And I'm happy you can appreciate the talent shown by the builder.

I didn't start this thread to "impress" or unimpress anyone. I'd simply like to know how it was possible 60 years ago to measure by proper inspection methods to that level of accuracy. And does metal change it's true dimensions over a period of time. I filled in what happened because I thought some might find it an interesting and odd occurence that just happens for no logical reason.

But the man who built this does deserve to be remembered as a true craftsman.

Pete

JCHannum
03-21-2012, 08:16 PM
That is a nice piece of work and a special treat to get it from the original maker. I have quite a few pieces that were shop made, a few that I also got from the original maker. I enjoy using them and try to give tham a bit of extra respect.

With that, fifty or sixty years ago is not the middle ages guys. A few here were starting on their apprenticeship then, and projects like this were often a part of that training. They were also made from cutoffs and drops while the machinist had time to spare while a long cut was being made.

Dr Stan
03-21-2012, 08:34 PM
While I of course cannot say exactly what method was used to measure to within 5 decimal places one can do so with an inspection grade set of gage blocks, a .0001" indicator (splitting the graduations), an inspection grade granite plate and an environmentally controlled inspection room. These are items one would expect Los Alamos to have in its inventory.

And yes in metrology 50 to 60 years ago is ancient history when compared with the computer controlled measuring equipment available today. Just take a look at a 50 to 60 year old car and compare it with a 2012 model and you'll have a similar yard stick. I've helped make repair parts for machinery of that vintage and the tolerances were much looser than what we use today.

That said, it is an excellent example of fine craftsmanship and the current owner is blessed to have the sine bar.

As to metal changing size over time the answer is maybe. In the case of a sine bar it's only going to change due to the change in temperature and would be based on the coefficient of contraction & expansion for that material (assuming one did not try to use it on a 5 ton workpiece). Other items could/would have a different answer. If for example a piece of metal was hung vertically with a weight on the end, the forces due to tension would cause it to stretch over time. Another piece in compression would shrink in height over time. A beam supported in the middle and one end with a weight on the unsupported end will bend over time. Other examples would yield similar results.

Peter S
03-21-2012, 08:51 PM
Nice sine bar (though it's true quality would require some slip gauges, surface table and comparator to check).

I made one fairly similar as a third year toolmaking apprentice, it was a standard project at our tech course and mostly rather simple. It was a good project because of the grinding skills required and particularly because it teaches about comparitive measurement, in this case comparing slip gauges to sine bar.

The "rollers' were made from one piece of bar, roughed out between centres with small diameter spigots each end and the middle parted but not right through, then hardened and ground as a single shaft between centres, final parting done on surface grinder with cut-off wheel. Because they are ground as one, diameter is not important, just that they are the same diameter, fairly easy to get on a cylindrical grinder.

Squaring up all sides of the sine bar on the grinder is a good skill, made easy if you have a square block (an essential tool to make and have if you are doing much grinding). Otherwise tedious.

Location for rollers is done using the relieved side of the wheel on surface grinder, so you learn about relieving and using a backstop.

The accuracy comes from checking it with a finger indicator on a surface table, sine bar vertical and comparing each roller location face to a stack of slip gauges. Comparitive checking like this is a basic, powerful tool, and would not have changed in 60 years. You can do it in your garage...

I still have mine wrapped up in oiled cloth...

BTW, you usually find tools like this are made by apprentices simply because you are not given time to fool about when you are a tradesman (Government work may be different!)

RussZHC
03-21-2012, 09:03 PM
I am certainly not at the skill or experience level of many on this board so my contribution here will be the love of "stuff" like this, "romanticized" perhaps but my mind just works imagining the whys, hows and wherefores, to me its a knowledge puzzle (see some of the comments in the EB thread as to the value of paper rather than electronic searches).

Anyway, with sine bars, which is the important part in terms of precision? Is it the flatness, the location of various holes or angles or is the the given length? Asking since, to me, the calculations involved change at great precision levels, so, could that account for the need to discern between 5" and 5.000034 (maybe a typo there, its mine) or 5.000035 say?

In terms of how did they measure this precise back then three thoughts:
(a) comparison to something more precise. With this you get into the discussion about how you get something as precise or more precise than what you have in your hand [I am thinking of the accuracy of index plates improving from a single hole...or so I have read] and so here it would be if it is this accurate, what did they compare it to? Or could there be something similar to the index plate thought...
(b) given the origin...when/how did they begin measuring a unit of time based on the decay of a given element? Would this have been something some of the same scientists were involved or would have known about? And if so, is there a way such knowledge could have been applied to measuring distance very, very accurately?
(c) regarding change in size/measured length, could the reason for such a precise measure be linked to a given temperature...I mean the most accurate gage blocks say, is there not a temperature as a "given" when those measurements are in fact true? So that only at that length would it be accurate...

Willy
03-21-2012, 09:06 PM
That is a nice piece of work and a special treat to get it from the original maker. I have quite a few pieces that were shop made, a few that I also got from the original maker. I enjoy using them and try to give tham a bit of extra respect.

With that, fifty or sixty years ago is not the middle ages guys. A few here were starting on their apprenticeship then, and projects like this were often a part of that training. They were also made from cutoffs and drops while the machinist had time to spare while a long cut was being made.

First of all Pete congratulations for being lucky enough to be the 'keeper' of this fine piece of craftsmanship for as long as need be.
Of course you already know that now it will be up to you to select a worthy recipient when the time comes to pass it on.

I agree with Jim's comment about this date (1952) not being that long ago and also wanted to comment on the high degree of machining accuracy prevalent in so many industries even well before that time.

The date struck a chord with me as it was also the same year that the mighty B-52 heavy bomber first flew. Think of all the myriad systems in this one example alone and the degree of accuracy required in order to make it successful. So successful that a viable replacement has still not been found, 66 years after the design contract was first let out!

There are other examples I'm sure, but it does indeed amaze me of the high degree of precision that machinists of that era and before displayed almost daily.

JCHannum
03-21-2012, 09:50 PM
The only real advantage CNC or CMM offer over methods used 50, 60 or 70 years ago is speed of measurement. The actual methodology is basically the same, comparing a part to a known standard.

Take a look around for some texts and catalogs from the late thirties and early forties to see how it was done. I have Pratt & Whitney and Van Keuren catalogs from this era and millionths were readily measured. I have a P&W toolmaker's flat that is lapped flat & parallel to 0.000010".

If you can, find Moore's Foundations of Mechanical Accuracy. It provides a great insight into just what mechanical accuracy is all about.

flylo
03-21-2012, 09:59 PM
Great tool & the history with it, can't beat that! Thank for sharing this with us.

uncle pete
03-21-2012, 09:59 PM
Well I've got a virgin set of NOS Mitutoyo grade 2 gage blocks I can use with this. But I personaly think it should be returned back to the U.S. when my times up. There might be a few specialised types of museums that might like it. I think the builder does deserve to be remembered. It's still tough to figure out to use it for what it was designed for or not. I'll have to at least once.

I also appreciate everyones posts about how it might have been measured. And as far as I know it's been properly stored on it's side since it was built.
No 60 years isn't that long ago, But it's a very long time ago compared to the standard high tech industrial measurement that's used today. JCHannum's point is of course correct, But our repeatable accuracy is far better today I think along with better abilitys to measure to much smaller limits.

Pete

oldtiffie
03-21-2012, 11:04 PM
Here is the link provided by the OP:

http://www.chaski.org/homemachinist/viewtopic.php?=4&t=92286

It looks like a typical "Apprentice Piece".

The "Inspection Sheet" sure does not look like a formal sheet that I'd expect from a place like LA - but it does look like a sribbled sheet from a trainer/instructor.

I'd have thought that in a formal training environment that the record (test results) would be in a pre-printed and headed tabular/tabulated form.

I'd expect to see the dimensions with their nominal sizes and limits/tolerances required as well as the sizes achieved by the trainee.

The centre distance is not all that important - say +/- 0.002>0.005" - but that they are parallel is as is that the top surface is accurately flat and parallel to the base is a "tight" requirement.

Width is not an issue nor is the base finish.

Here is how a sine bar works:
http://i200.photobucket.com/albums/aa294/oldtiffie/Sine_bar/Sine-bar_setting1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Sine_bar/Sine-bar_setting2.jpg

Those sorts of "Training" projects have been around for a long time. I've seen Tradesmen 30>50 years older than I was who had their own or some passed down/on to them. There was a lot of that in drawers and tool-boxes.

For the OP:

Can you please scan and post that "score sheet"? as I'd like to see it.

Horst
03-21-2012, 11:22 PM
It looks like a typical "Apprentice Piece".

This guy has no appreciation of fine tools. Just ignore him. The sine bar is a real treasure.

oldtiffie
03-21-2012, 11:41 PM
.......................................

Last month there was a post made by a gentleman in his early 80's showing a Sine Bar built by his long deceased friend on the Chaski forum.

...........................................




That is a nice piece of work and a special treat to get it from the original maker. I have quite a few pieces that were shop made, a few that I also got from the original maker. I enjoy using them and try to give tham a bit of extra respect.

With that, fifty or sixty years ago is not the middle ages guys. A few here were starting on their apprenticeship then, and projects like this were often a part of that training. They were also made from cutoffs and drops while the machinist had time to spare while a long cut was being made.

Jim,
that sine bar was second-hand when the OP got it - and not from the original owner/maker.

If I was "into" historical or "keep-sake" stuff - in any manner shape or form - which I certainly am not - I'd give it a "miss" or a "pass" if it were offered to me.

It seems that there are enough others who appreciate it more then I would so if it goes to them (as it is now with the OP) then I am glad for them.

ckelloug
03-21-2012, 11:46 PM
Horst,

Remember Tiffie was once an apprentice in Australia in a time period where society took machining a bit more seriously. I assume he built and saw his classmates build pieces that are at least a bit like this. I must admit that the piece in question is absolutely gorgeous by my standards and I think that it is incredibly special. But, it light of Tiffie's comment, perhaps there is more of this special and inspired work out there than we realize if we only knew where to look.

Incidentally, At least through the 1980's the national labs had the very best technicians, machinists and metrologists he world had to offer. Because of the weapons work done at Los Alamos and the sheer oddities of it, they need a way to measure just about anything especially back in the 1950's before you could run a computer simulation of things. I worked briefly at Los Alamos in college and have a lot of friends at LLNL. My LLNL friends tell me stories of the machinists doing extremely high accuracy work not only in ordinary metals but in radioactive materials, ceramics, and other things.

oldtiffie
03-21-2012, 11:55 PM
Thanks muchly Cameron - you sort of let the cat out of the bag somewhat.

For others:

note that I've never (so far as I recall) ever called myself a "Machinist" here.

Perhaps that may confirm some opinions - one way or the other.

But I make no apology for being a sceptic when I see this sort of thing come up.

http://www.google.com.au/#hl=en&rlz=1W1IRFC_enAU360&sclient=psy-ab&q=sceptic&rlz=1W1IRFC_enAU360&oq=sceptic&aq=1&aqi=g4&aql=&gs_l=hp.1.1.0l4.0l0l1l764l0l0l0l0l0l0l0l0ll0l0.frg bld.&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=56afa242754894c9&biw=1920&bih=785

oldtiffie
03-22-2012, 12:37 AM
Horst,

Remember Tiffie was once an apprentice in Australia in a time period where society took machining a bit more seriously. I assume he built and saw his classmates build pieces that are at least a bit like this. I must admit that the piece in question is absolutely gorgeous by my standards and I think that it is incredibly special. But, it light of Tiffie's comment, perhaps there is more of this special and inspired work out there than we realize if we only knew where to look.

............................



Cameron.

At the end of each phase/year/term after my "pieces" and projects were complete and had been assesses/marked/recorded, they were "binned" as I put those stages behind me and moved on.

Each year and at the end of my Apprenticeship I had a "clean slate". I set about getting the money via over-time etc. to progressively buy good and better tools etc. within my budget as the work required. If I chose incorrectly and if I could not see any real use for them I either gave them away or "binned" them and put it all down to experience. I never "hung on" for the sake of it - and still don't.

So I appreciate good tools - no matter where made or who by or brand etc. - and if necessary I buy them - new.

When I joined the Navy as an Ordnance Artificer (OA) - with several others in the same class - our "Trade Test" was a copy of a Moore & Wright surface guage. We were marked for accuracy, time, methods, sequence, finish and function. Suffice to say that I was more than pleased with mine. At the end, the Chief OA marked them, discussed where we went right and wrong and he promtly tossed them over the wharf to sink in 10+ feet of marine mud etc.

I was glad to see it go. Others were disbelieving, some were shocked, others carried on as if they'd lost a child and the rest of just shrugged our shoulders and moved on.

That crafty old COA assessed that reaction as well and reported it - as he was required to do - and it was all marked on our "papers".

When I know or feel that my time in the shop is "up", I will just turn my back on it and set about getting rid of all those tools and machines etc. (to scrap mainly) and not miss any of them.

I have no sentimental attachment to any of it and/or a lot more as well.

Same with the house etc.

As long as my wife is OK, I am OK and she is OK if I am.

I/we can't do better then that.

Mike Burch
03-22-2012, 12:59 AM
As far as losing accuracy over time goes, in the absence of trauma your lovely sine bar probably won't change much over a lifetime.
But I read something recently which is vaguely relevant to this discussion, and which interested me greatly. It seems that the world's standard mass of one kilogram, a lump of platinum which has been kept in a vault in Paris for more than a century, is slowly losing material. It is in fact no longer exactly one kilogram, and so it can't be used as the world's original comparison piece any more. Apparently the secondary standards are now more accurate than the primary one.
I have not seen any explanation of this.
Evaporation?
Radioactivity?
I'm not wanting to hijack the thread, by the way.

oldtiffie
03-22-2012, 02:01 AM
Mike.

It is no hi-jack.

You are correct:


The International Prototype Kilogram is kept in the custody of the International Bureau for Weights and Measures (BIPM) who hold it on behalf of the General Conference on Weights and Measures (CGPM). After the International Prototype Kilogram had been found to vary in mass over time, the International Committee for Weights and Measures (CIPM) recommended in 2005 that the kilogram be redefined in terms of a fundamental constant of nature. At its 24th meeting the General Conference on Weights and Measures (CGPM) agreed in principle that the kilogram should be redefined in terms of the Planck constant, but deferred a final decision until its next meeting, scheduled for 2014.

from:

http://en.wikipedia.org/wiki/Kilogram

gwilson
03-22-2012, 02:12 AM
It is very late,and I am sleepy,but cannot sleep. Does anyone recall Maudslay's(sp.?) millionth measuring micrometer from the early 19th.C.? Even today it is still quite accurate. it was called the "lord chancellor" About 1809.

JRouche
03-22-2012, 02:27 AM
What a phuckin joke!! Uncle Pete. Im solly. The lack of nostalgia is a down fall of this forum.

I dont expect anyone to embrace it. But when they go out of their way to piss on it and your original thought for the post it makes it a forum less traveled.

The pissing contest NEVER ends here huh guys? LOL

I for one love your story and glad that the tool landed in the CORRECT hands VS the hands of well, some of the folks that just dont get it. JR

uncle pete
03-22-2012, 02:44 AM
Gwilson,
Yes I've read a few bits and pieces about it. Quite an amazing feat considering the time period and the technology avalible. But I'm a bit unsure of exactly who built it too. Maybe Whitworth? I do remember there were lots who thought is was impossible to build a micrometer to that accuracy level till he proved them wrong. The screw cutting lathe hadn't even been around all that long when that millionths reading micrometer was built. Less than 50 years I think.

Mike,
That was an interesting detail about that kilogram standard loseing weight. I hadn't heard that before now.

Pete

mike4
03-22-2012, 03:02 AM
This guy has no appreciation of fine tools. Just ignore him. The sine bar is a real treasure.
As OldTiffie said , often during the course of an apprenticeship you would be given a set atsk to make a tool or some part.
The trainer or examiner was looking at you ability to turn out an item which closely matched the dimensions on the drawings which each student was given .
I made a square which I still have and do use for setting up some jigs , however most of what I made was never seen again once it was put in a wooden tray with my name on it and left on the examiners desk .
We all received a mark which counted towards the final exam ,and passing that exam was very important not the items we produced along the way .
The important items came later when the successful students got their first jobs and started to make parts for repairing machines or for sale to customers of their employer.
The thing that I treasure is my trade certificate because I know what went into getting that piece of paper.
I do appreciate decent tools and have still got some of my original metrology gear from my apprenticeship , but they are still used not admired.
Michael

oldtiffie
03-22-2012, 05:23 AM
It is very late,and I am sleepy,but cannot sleep. Does anyone recall Maudslay's(sp.?) millionth measuring micrometer from the early 19th.C.? Even today it is still quite accurate. it was called the "lord chancellor" About 1809.

Almost but not quite.

Maudsley's micrometer was 100 times less accurate than that - ie to 1/10,000 (0.0001") which was extraordinary in those days but just about any common shop micrometer can do it today.


Maudslay invented the first bench micrometer capable of measuring to one ten-thousandth of an inch (0.0001 in ≈ 3 m). He called it the "Lord Chancellor", as it was used to settle any questions regarding accuracy of workmanship.

from:

http://en.wikipedia.org/wiki/Henry_Maudslay

oldtiffie
03-22-2012, 06:05 AM
What a phuckin joke!! Uncle Pete. Im solly. The lack of nostalgia is a down fall of this forum.

I dont expect anyone to embrace it. But when they go out of their way to piss on it and your original thought for the post it makes it a forum less traveled.

The pissing contest NEVER ends here huh guys? LOL

I for one love your story and glad that the tool landed in the CORRECT hands VS the hands of well, some of the folks that just dont get it. JR

Its true that I am not "into" nostalgia generally as I just cannot and will not get sentimental about inanimate objects - tools and machines included.

I am impressed though if they perform their intended function very well in what may be a unique way.

I am still inclined to think that that sine bar is just an apprentice's "test piece" as it has all the ear/hall marks of being one.

The issue was mainly "accuracy" for the period in which it seems to have been made - that's all.

I challenged the size of the roller centres and as good as said that it was pretty ordinary - which I still think it is now and was then.

I asked the OP to post a copy of the marking sheet to see what other limits there were and how the sine bar met those limits.

As the OP has the sine bar and the box it came in, I was rather hoping that it came with that bit of paper in the pics too and that he would post a pic of it.

That peice of paper may resolve the issue definitely and objectively without any subjective sentimentality.

Easy as that.

If it is as I suspect, I'd have made sure it neither landed in nor stayed in my hands.

It could well have been a task set to the ex-apprentice now Journeyman as he applied for a job for which he had to prove himself (as was common in the old Guilds and the like).

If there was to be any sentimental value at all, I would have thought it should have been in the hands of his family as a keep-sake.

Sentimental or intrinsic value normally required a credible history and a valid story. A family is the likely best source of those.

Peter S
03-22-2012, 08:13 AM
The owners name on the sine bar looks like it might be a label glued into milled recesses?

Milling a recess for your name was my standard apprentii procedure, it allows for grinding after hardening, without harming the lettering, and looks good if done right. I didn't use labels, but letter and number stamps, but you only get one chance! Recess made just the right length for your name and the correct width to keep the punches in line.... I have round tools I made where I set them up in a dividing head to mill the name recess...this is the sort of bollocks only apprentii (and government workers?) can get away with. :p

Doozer
03-22-2012, 08:46 AM
oldtiffe-
I see the world so much different than you.
You give me the general opinion that you don't care for or respect the effort that someone put into making something. You don't seem to think anything is special except family.
Some people don't give a damn about having offspring or a family.
Some people don't believe making babies adds to the betterment of society.
Some people believe adding to the collective knowledge (culture) of society is what makes it great.
Some people practice the arts of using technology and try to advance it to a higher level to try and evolve society to a higher level.
Some people like to celebrate this persuit of advancing technology and adding to the evolution of society by appreciating the inventions and tools that allowed this evolution to take place.
A man appreciating a tool that helped advance the technology of his society is like a man admiring a war hero for expanding his society's freedom.
To belittle or make light of someone's appreciation of an object and the contabution it represents to society is self centered and nasty.
Why make little of someone seeing worth in an object that has a history of demarkating an important placeholder in the timeline of the evolution of our culture and society?

-Doozer

John Stevenson
03-22-2012, 09:06 AM
For others:

note that I've never (so far as I recall) ever called myself a "Machinist" here.



Perhaps because you have never made anything ?

HWooldridge
03-22-2012, 02:29 PM
I have a book here titled, "Inspection and Gaging" by Kennedy and Andrews. First printing in 1951, our copy was from the last edition in 1977. There is an entire chapter titled "Measuring in Millionths" which explores many of the variables that can affect measurements at this level - including deflection, indicator penetration, temperature, etc. With respect to the actual gages, a variety are used - from air gages to master gage blocks and surface plates. That being said, it's clear that the subject has been in discussion since at least WW2.

We currently have mechanical indicators in the shop that read to .000050 so a sturdy setup on a good surface plate should yield good results in a controlled environment to measure a sine bar - and this type of equipment was readily available 60 years ago.

oldtiffie
03-22-2012, 02:49 PM
oldtiffe-

.............................

..............................

To belittle or make light of someone's appreciation of an object and the contabution it represents to society is self centered and nasty.
Why make little of someone seeing worth in an object that has a history of demarkating an important placeholder in the timeline of the evolution of our culture and society?

-Doozer

I have not be-littled the OP's - or anyone else's - appreciation of anything - that sine bar included.

It may be not be bad for an apprentice but to equate it with the high point of excellence as regards accuracy in the era in which it seems to have been made is stretching things more than a little bit.

My guess is that it was made by an apprentice or trainee in his late 'teens or early 20's who passed it on when he was say in his 60's to another of the same age span (20>60) who passed it on to the OP. That seems that it was made somewhere like 80 years or less years ago.

I am 75 and I can tell tell you that even in the backwoods and boondocks of wildest Australia - and in the cities too - there was any amout of "accuracy" and "manual skills" of at least the order of the sine bar with plenty of evidence of it from those who had made them and those who had them from previous owners/makers.

I have no issue with anyone admiring the sine bar itself or the skill level of the person who made and incribed his name into it but to elevate it to a level of an example of the highest order of accuracy for the period is a bit much.

I'd still like to see the "marking sheet" the was with the sine bar in the pics in the original link.

oldtiffie
03-22-2012, 03:12 PM
I have a book here titled, "Inspection and Gaging" by Kennedy and Andrews. First printing in 1951, our copy was from the last edition in 1977. There is an entire chapter titled "Measuring in Millionths" which explores many of the variables that can affect measurements at this level - including deflection, indicator penetration, temperature, etc. With respect to the actual gages, a variety are used - from air gages to master gage blocks and surface plates. That being said, it's clear that the subject has been in discussion since at least WW2.

We currently have mechanical indicators in the shop that read to .000050 so a sturdy setup on a good surface plate should yield good results in a controlled environment to measure a sine bar - and this type of equipment was readily available 60 years ago.

I'd agree with all of that.

But the issue is not so much the accuracy of measuring things - sine bar included - but the accuracy in making them - sine bar included - as an example of the high(est?) order of both less than 100 years ago.

My stance is that the order of accuracy - and measurement - of that order was not at all uncommon at that time and probably well before it.

I still want to see that marking sheet.

Mcgyver
03-22-2012, 03:34 PM
Its true that I am not "into" nostalgia generally as I just cannot and will not get sentimental about inanimate objects - tools and machines included.


This may well be true for your made in China tools, not that there's anything wrong with them, but it is hard to find a kinship with the human spirit in their possession.

Where you miss the point is that the nostalgia or sentiment about inanimate objects isn't in the objects, its in the human spirit that went into to their making. It the risk of sounding corny about it, its why great art is great, it conveys some humanity, a feeling, emotion. Its not the molecules of marble or paint. You must have some sense of this as you think it should be with a family member. I don't get why you think someone else, a stranger, can't find equal value and appreciation in thinking of its creator working away with the outmost of care creating a very nice tool.

This is in the same vein as you believing its ok to destroy something just because you own it. Again, its a denial of your connection with humanity - that you have no responsibility of goodwill toward the next person who might be able to use it (I actually doubt you really think that way as witnessed by your passing along of magazines, however you like to project that you do).

You misplace the emphasis; its not on the object, its on the human spirit that created it.

Where I do agree with you is the idea that it could well be an apprentice's work. Not at all because of reflection of quality, only that apprentices had the time to make their tools and we encouraged to do so. imo that makes it not an iota less special or of less quality. Take the best sr apprentice in the class working with the best toolmaker and what he puts out is going to be first class. Don't most highly skilled men build their tools in their apprenticeships and then use them for the rest of their career? The good ones did good work in the apprenticeships, I seen over and over and have the shop made tools with their names stamped on them to prove it.

John Stevenson
03-22-2012, 03:45 PM
Don't most highly skilled men build their tools in their apprenticeships and then use them for the rest of their career? The good ones did good work in the apprenticeships, I seen over and over and have the shop made tools with their names stamped on them to prove it.

This sentence from Mac's post says it all.

mikem
03-22-2012, 04:01 PM
The "news" of the original post was that the previous owner enjoyed the poster's comments about the bar and sent it as a gift--a touching gesture. Not that it is a "stradivarius" measuring tool. Someone did a nice thing for a fellow board member. Let's celebrate that!

oldtiffie
03-22-2012, 04:08 PM
One of the reasons I divorce sentiment from the shop is that I see too much fervour that is approaching religious levels about inanimate objects.

I certainly do not "connect" with people or anything else via tools etc.

If others do - fine - I have no problems there.

But when others wax lyrical or evangelical about tools it leaves me cold.

I do appreciate fine art and music - but only because I like it - nothing more and nothing less.

If my shop and its contents disappeared tomorrow (today? tonight?) I'd either replace all or part of it - or none at all - and get on with life.

There is plenty else to do.

willmac
03-22-2012, 04:10 PM
I have tools that I have made myself, tools made by my grandfather, a couple of great uncles and other people I have known. Most of them have their names stamped on them. I also have some of their bought tools such as micrometers. I learned a lot from these people. The old tools are still very usable, but many of them had hard use and acquired a bit of a 'patina'. I have new versions of some of them that are better looking and more accurate, but I actually enjoy using the old ones occasionally . It reminds me of them in a small way. I have already sorted out what will happen to my tools when I go and I do not expect any tools with this family heritage to get thrown out. The recipients will use them and get value out of them or pass them on to someone who will. We should never be owned by our possessions but neither should we disrespect the work and skill that went into them, nor the real value that they have to a new generation.

There are a diminishing number of people who understand what it takes to make good precision tools. I would hate to see this appreciation lost.

oldtiffie
03-22-2012, 04:22 PM
.................................................. ....
Don't most highly skilled men build their tools in their apprenticeships and then use them for the rest of their career? The good ones did good work in the apprenticeships, I seen over and over and have the shop made tools with their names stamped on them to prove it.

There are many here who by any definition are "highly skilled men" who were not apprentices and did not make their tools and thus cannot use them for the rest of their careers - but either despite that - or because of it - they get by very well indeed.

It seems that the attraction for "personally made tools" by "others" with their name enscibed is the "value" component.

So as to "distance" the "marker" from the "maker" the "maker" was quite often given a number to use (not known to the "marker") so that any personal bias of the marker toward the maker is eliminated and the marker could mark objectively.

There are many shop-made tools "out there" which are very functional but may not necessarily be regarded as "attactive" - or "works of art" - but they are very useful and are kept for that reason alone and may be tossed-out when they are of no further use and/or just "get in the way".

uncle pete
03-22-2012, 04:51 PM
I've read everyones comments here I can view. I don't look at this as "my thread", I more than enjoy and appreciate any tooling that the builder put some time and effort past what the actual tool required. That to me shows some personal pride and dedication. If you've got pictures of old or brand new? I'd love to see them as I'm sure many others here would also enjoy it. As I said at the beginning of this. It sure as hell doesn't hurt to think about the people who built or even owned the equipment. John Stevenson does something like it with his collection of tool boxes. I happen to think that's a very respectable personal tradition.

Pete

John Stevenson
03-22-2012, 05:31 PM
Pete,
Basically it's just pride.
Whether it's pride in doing a job, pride of ownership or proud that you knew someone you respected.

If you don't have any of that it's time to take up knitting with blunt needles and in which case this is the wrong forum for those people.

oil mac
03-22-2012, 05:55 PM
I for one thoroughly applaud Uncle Pete ,in sharing with us the nice sine bar, made by a craftsman over the pond, The love of craftsmanship, nice mechanical things, & general interest in how things were done etc, is the cement which binds us together as a brotherhood of craftsmen

Nowadays we live in a functional utility age, modern buildings e.g. office blocks, apartments shopping malls etc, are souleless places (to emphasise a point)

Many years ago, as a youngster, one of the collieries where i worked had a large steam engine driving a ventilating fan, this item of plant was lovingly looked after by an old almost retired engineman He kept it immaculate, polished ,cleaned and made sure it was 100% efficient This old boy liked nothing better than opening the crank case auxiliary door and letting us young guys see the nice polished connecting rods flailing round His engine was his pride &joy

The engine was exactly the same age as me at that period 17 years old, O.K
. modernisation dispatched it The old fellow was devastated, He had lost a friend with the passing of what he percieved to be a fine example of engineering craftsmanship

without our love of nice things, things of interest, & knowledge we would not be a brotherhood O.K. again we no doubt might pursue innate hobbies & pastimes like lots of todays somewhat shallow airheads

Without the nice machines &tools i own i would be further away from my humanity & the past path the good Lord gave me to follow through life This does not mean i should not look forward & still admire the best examples of modernisation of a tasteful quality which we occasionally may happen upon But still never disregard but always have a love of fine craftsmanship as made by the hand of others, We owe it to the memory of the past craftsmen &our brothers to save this material for posterity, &not throw it over the rail with scant regard Without adopting this approach the world will surely be a more souleless place devoid of culture.

sasquatch
03-22-2012, 06:10 PM
Excellent post Mac!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

gwilson
03-22-2012, 06:13 PM
I,for one,am always excited when I can get a real nice tool that someone made.

I have several tools that an old time machinist named Quigley made. He must have worked many many years ago judging from the appearance of his beautiful work. I got his toolbox too. It was made in the last quarter of the 19th.C.. I started buying tools from his completely full tool box in the early 60's from a dealer who had gotten it. I wish I could have bought all of them,but just didn't have the money that the dealer wanted back then.

Everything he made was hardened and ground. He made his own gage blocks and taps and dies,and the holder. I even have an early style of indicator he made. It can only be used in a lantern type tool post. I also have a beautifully made knurling tool that he made. It can only be used in a lantern type toolpost also. It has a difficult to make joint in it that is very well made,but was a LOT of trouble to do. He took a lot of pride in his work.

I used to have a ball pein hammer he made. It was made of tool steel,drawn to a fire blue color. The area around the eye was octagonal,and faceted as nicely as a fine stone. Unfortunately someone walked off with it years ago. I still wish I hadn't lost it.

I have a whole set of small drill bits that have hand filed flutes. I don't know if he made them,but this is why the universal milling machine was invented. Workmen in the mid 19th.C. would patiently file the spiral flutes in their drills by hand. Brown,or Sharpe(can't recall which) saw a workman doing this,and invented a way to mill them out. They may be an indication of how old the pieces are in general.

I have wondered if this machinist worked for the government,judging from the large number of very carefully tools he made for himself. No doubt they covered a long career. I contrast these tools with the bitter attitude that an old 19th. C. carpenter had. When he was very old,he bURNED all his tools because they had caused him so much trouble! That is sad. A life lived out of joint. Quigley's wasn't.

If my shop was burned,I could start it over again,sure,but it wouldn't be the same.

oldtiffie
03-22-2012, 06:27 PM
I think I have a fair appreciation of what a good tool is - it does the job required of if and does it well without too much over-capacity.

While it meets those criteria and there is a reasonable possibility of it being needed in the foreseeable future, I keep it an look after it. Other than that its likely to be dumped.

There is no sentimental "baggage" attached to it while I have it - or when I get rid of it.

The trick for me is knowing what I need and either buying it or keeping it that way - no more or less.

I don't care who makes a tool or where it is made - anywhere on the planet - as long as it does its job.

I don't want and don't need any "histoty" or emotion attached to it by me or anyone else. That sort of "baggage" I can do without.

So its not likely that there is much chance of my shop being a museum or a cathedral (me with my own private chapel where I can commicate with "previous owners" etc? I think not).

Now having said that for the umpteenth time, I will also say - for the umpteenth time - that it is my opinion and the way I choose and prefer to go and be.

I respect the opinions of others and their right to do as they wish and to be different to me - absolutely.

oldtiffie
03-22-2012, 06:56 PM
For those that may have forgotten or chose to ignore it, the title/heading of the OP by the OP at post #1 of this thread is:


State of the art accuracy 60 years ago?

How about we get back to that topic and stick to it without any sentiment or side-issues (hi-jacks? - or just "diversions").

I'd (still and again) like to make my own objective judgement of the actual accuracy of the OP's sine bar (if and) when I see the marking sheet in the pics earlier in this thread:

http://www.chaski.org/homemachinist/viewtopic.php?=4&t=92286

oldtiffie
03-22-2012, 08:23 PM
I've read everyones comments here I can view. I don't look at this as "my thread", I more than enjoy and appreciate any tooling that the builder put some time and effort past what the actual tool required. That to me shows some personal pride and dedication. If you've got pictures of old or brand new? I'd love to see them as I'm sure many others here would also enjoy it. As I said at the beginning of this. It sure as hell doesn't hurt to think about the people who built or even owned the equipment. John Stevenson does something like it with his collection of tool boxes. I happen to think that's a very respectable personal tradition.

Pete

Pete.

I can't really see how thinking about the tool maker without some sort of narrative or valid history to go with it is possible.

I can't see that anyone can "connect" with the maker of the sine bar for instance as other than knowing his name we know nothing else of him in terms of the sine bar or where he lived or worked and in what period or era.

We don't know if he even used his sine bar.

This is mystery upon an enigma stuff.

oldtiffie
03-22-2012, 09:09 PM
It occured to me to list what I do like about tools and people.

It is mainly an appreciation of the skill, effort, time and planning - and patience and perseverence too and lots of them - to achieve extraordinary results - because I can relate to them here by their posts and pics and the interaction with people here - in close to "real time".

I can contact them here if I want to if needs be.

Two recent and current examples are:

http://bbs.homeshopmachinist.net/showpost.php?p=753546&postcount=19

http://bbs.homeshopmachinist.net/showthread.php?t=51118

mike4
03-23-2012, 06:05 AM
Now that we have all said whether we use or appreciate tools or both , I would like to see if anyone has bothered to compare their apprentice made or shop made items whatever the case may be to the products of today .
It may be surprising to some that the old gear was very accurate and gave repeatable results .
Otherwise many of the machine that people on this board posess or lovingly "restore" would not be held in the esteem that they are , nor would many of the still operating large machines have lasted as long as they have.

Rather than engaging in bashing each other because our opinions are different , why not work together and help this area of technology survive .
Many of us arent getting any younger ,maybe a bit crankier, so lets keep the art of making or repairing machines or attachments alive and try to foster the interest of younger generations in machines and their use.
Michael

sasquatch
03-23-2012, 08:29 AM
Very good post Mike4,, And the bottom line to all this in my opinion is that the maker was an excellent machinist. Period.

uncle pete
03-23-2012, 09:58 AM
Because of my own curiosity, I just sent a email off to the Los Alamos site to see if I can get any further information about Mr. Marlett and Mr. Pertersen who measured this tool. If? I get anything back I'll post it. Suprisingly, The site is large and old enough to have it's own historical society.

Pete

ckelloug
03-23-2012, 10:05 AM
Because of the type of work done at Los Alamos and the need to track radiation doses, there are surprisingly detailed records as I understand it. If any of the paperwork happens to contain a number starting with a N, it's quite possibly an Employee ID number. Can't remember how many digits. HR told me that these N numbers were permanent identifiers assigned to everybody who had ever worked there.

uncle pete
03-23-2012, 10:26 AM
ckelloug,
Many thanks for that, I finally managed to get the paperwork opened up. After 60 years it's really delicate. Unfortunately there's no N numbers or employee numbers on it at all. Your information along with the employee numbers would have made things much easier I bet.

Edited to add, I just got a very nice email from Los Alamos and they've forwarded my inquiry to the archivist and to the historian. They said they were glad to help. This might be easier than I had thought it was going to be.

Pete

oldtiffie
03-23-2012, 11:37 AM
Thanks Pete.

Can you now post a copy of that bit of paper so they we can each make a judgement of any details additional to (and including) the sine bar roller centre distance.

As previously, it appears that it was made by Mr. Marlett and marked by Mr. Pertersen.

Presumably it is Mr. Petersen's signature at the bottom of the page. It was customary to include a date as well. If so, that will pin down the date of manufacture by Mr. Marlett.

LANL was opened during World War 2 (say 1937>40):


The laboratory was founded during World War II as a secret, centralized facility to coordinate the scientific research of the Manhattan Project, the Allied project to develop the first nuclear weapons. In September 1942, the difficulties encountered in conducting preliminary studies on nuclear weapons at universities scattered across the country indicated the need for a laboratory dedicated solely to that purpose.

http://en.wikipedia.org/wiki/Los_Alamos_National_Laboratory

That would suggest that the earliest that either Mr. Marlett and Mr. Pertersen could have joined LANL was 2012 - 1937 = 75 years ago.

If that is so, and if the the sine bar was made while both were at LANL it would suggest that the sine bar is no older than 75 years which is in or approaching the modern era.

I would guess that the sine bar was made by Mr. Marlett when he was about 20 years old when he made that sine bar which would make him about 75 = 20 = 95 years old if he were alive today.

I would guess that Mr. Petersen would need to be at leaast about 20 years older than Mr. Marlett which would make him about 95 + 20 = 115 years old if he were alive today.

The date with Mr. Petersen's signature on it (if it is on that bit of paper) is pretty important here.

If there is no identification of LANL on that bit of paper it might suggest that the sine bar was made before either worked at LANL which would make the sine bar older still and that it was made and measured before either worked at LANL.

But the issue here is not so much a matter of time but accuaracy as per the heading in you original post: "State of the art accuracy 60 years ago?":
http://bbs.homeshopmachinist.net/showthread.php?t=53399

I'd appreciate seeing that bit of paper to both get the date of marking by Mr. Petersen and presumably of making by Mr. Marlett.

Hopefully that bit of paper will give some other measurements of the sine bar as well as the limits or tolerance range to be achieved.

Any other or further information along those lines from the LANL Historical Society will be appreciated.


Because of my own curiosity, I just sent a email off to the Los Alamos site to see if I can get any further information about Mr. Marlett and Mr. Pertersen who measured this tool. If? I get anything back I'll post it. Suprisingly, The site is large and old enough to have it's own historical society.

Pete

This quote of yours suggests that the paper is 60 years old which would date the marking and making of the sine bar:


ckelloug,
Many thanks for that, I finally managed to get the paperwork opened up. After 60 years it's really delicate. Unfortunately there's no N numbers or employee numbers on it at all. Your information along with the employee numbers would have made things much easier I bet.

Pete

I will stick to the objective measuring as that is or seems to be the intent of the OP/thread.

Others can make their own assessments of subjective matters such as "looks", "finish", heritage and historical values as well as personal matters etc.

oldtiffie
03-23-2012, 07:42 PM
Ok,

I've read just enough about the Los Alamos site to have some ideas about what kind of accuracys were needed, And just how good you would have to be to even work there as a machinist or tool maker. Given that this was a fully funded and controlled government site. And the precision required to even do the work. Then logicly the equipment and methods used would have been to the highest accuracy standards, Actual costs would have been immaterial. The 60 year old hand drawn sketch done by the original builder was included with this sine bar. The inspectors exact measurements were also marked down in five decimal places. The center - center distance for the round rolls are given as 5.00034. There's a lot of members here with far more knowledge than mine. So I'm wondering if anyone here could give an example or at least a few thoughts about what would have been used to measure to these accuracy levels 60 years ago? Gage blocks accurate to within millionths have been around since the 1920s. I've yet to find out how those exact measurements were obtained.

.


The 60 year old hand drawn sketch done by the original builder was included with this sine bar. The inspectors exact measurements were also marked down in five decimal places. The center - center distance for the round rolls are given as 5.00034.

Pete,

in the era of 60 years ago a meaurement to 5 decimal places was not uncommon. Metrology was quite advanced even then and using a good (Class/Grade 2 "shop") quality slip guages and high resolution indicators would ave covered that relatively easily. Perhaps better result sould have been obtained with the then available Class/Grade 0 (Laboratory) or Class/Grade 1 (Inspection) slip guages may have done better than that though I doubt it.

Slip guages are accuarate to 6 decimal plases (ie "millionths" of an inch) as so are one order of magnitude more/greater than the 5 decimal places of the 5.00034" (which is 0.00034" - 3.4 "tenths" - above the presumed required nominal 5" sine bar roller centre distances.


A gauge block (also known as a gage block, Johansson gauge, slip gauge, or Jo block) is a precision ground and lapped length measuring standard. Invented in 1896 by Swedish machinist Carl Edvard Johansson,[1] they are used as a reference for the calibration of measuring equipment used in machine shops, such as micrometers, sine bars, calipers, and dial indicators (when used in an inspection role). Gauge blocks are the main means of length standardization used by industry.[1]



Gauge blocks are available in various grades, depending on their intended use.[6] The grading criterion is tightness of tolerance on their sizes; thus higher grades are made to tighter tolerances and have higher accuracy and precision. Various grading standards include: JIS B 7506-1997 (Japan)/DIN 861-1980 (Germany), ASME (US), BS 4311: Part 1: 1993 (UK). Tolerances will vary within the same grade as the thickness of the material increases.
reference (AAA): small tolerance (0.05 μm or 0.000002 in) used to establish standards
calibration (AA): (tolerance +0.10 μm to −0.05 μm) used to calibrate inspection blocks and very high precision gauging
inspection (A): (tolerance +0.15 μm to −0.05 μm) used as toolroom standards for setting other gauging tools
workshop (B): large tolerance (tolerance +0.25 μm to −0.15 μm) used as shop standards for precision measurement

More recent grade designations include (U.S. Federal Specification GGG-G-15C):
0.5 generally equivalent to grade AAA
1 generally equivalent to grade AA
2 generally equivalent to grade A+
3 compromise grade between A and B

and ANSI/ASME B89.1.9M, which defines both absolute deviations from nominal dimensions and parallelism limits as criteria for grade determination. Generally, grades are equivalent to former U.S. Federal grades as follows:
00 generally equivalent to grade 1 (most exacting flatness and accuracy requirements)
0 generally equivalent to grade 2
AS-1 generally equivalent to grade 3 (reportedly stands for American Standard - 1)
AS-2 generally less accurate than grade 3
K generally equivalent to grade 00 flatness (parallelism) with grade AS-1 accuracy

The ANSI/ASME standard follows a similar philosophy as set forth in ISO 3650. See the NIST reference below for more detailed information on tolerances for each grade and block size. Also consult page 2 of: Commercial Gauge Block Tolerances (Length refers to the calibrated thickness)

from:

http://en.wikipedia.org/wiki/Slip_gauges


So, all in all, I'd say that based on what I've seen so far here the sine bar seems to have been made by an apprentice or trainee and marked about 60 years ago.

It seems to be a good example of Apprentice skill levels and capability.

I would not go so far as to class it as "Given that this was a fully funded and controlled government site. And the precision required to even do the work. Then logicly the equipment and methods used would have been to the highest accuracy standards"

Here are the limits for various grades of sine bars. Note that the dimensions/figures are in micrometer = um = "micron" = ~0.00004" say 0.4 "tenths"

http://www.scientific.net/AMM.44-47.3584


A micrometre (or micrometer) is by definition 110−6 of a metre (SI Standard prefix "micro" = 10−6). In plain English, it means one-millionth of a metre (or one-thousandth of a millimetre, 0.001 mm, or about 0.000039 inches). Its unit symbol in the International System of Units (SI) is μm. The latter may be rendered as um if Greek fonts are not available or not admissible.

from:

http://en.wikipedia.org/wiki/Micrometre

It should be note that a sine bar is not only for "setting" but for "measurements" as well and is a test instrument and should be made and regarded accordingly.

The OP's sine bar centre distance at 5.00034" is 0.00034" (3.4 "tenths" ~ 8.5um or micrometers) oversize and falls outside limits of the least grade sine bar of +/- 3um

I would expect that those limits for those grades of sine bars were applicable 60 years ago.

Now whether they were applied in a school/college training environment may well be another matter.

oldtiffie
03-23-2012, 09:47 PM
In summary (at last?) it seems to me that subject to my not having a copy of the marking paper, that the sine bar is not "way up there" as regards the accuracy required of a sine bar nor the highest order of acheiveable accuracy for the time/period, but a good piece by an apprentice or trainee that seems to look very well and made about 40 years ago.

That seems to settle the "accuracy bit".

Others may continue to admire it for its aesthetic value and for any historic or personal aspect it may have or be seen to have.

For my day to day angular settings and measurements I prefer my "Chinese" "Vertex" 6 rotary table which is calibrated directly to 20 arc seconds which is very close to 1 in 10,000 or 0.0001" per inch. It is easy to interpolate it to half that at 10 arc seconds.

I use a parallel strip or an angle plate on the rotary table. Set it to zero "run-out" ar zero degrees on the rotary table and away I go.

I don't have (and neither want nor need) a standard sine bar as such but I do have "sine vises" and a sine magnetic chuck (tilting) - all "Chinese" of course - and so far as I can tell they are very good and meet my every need.

John Stevenson
03-24-2012, 06:02 AM
In summary (at last?) it seems to me that subject to my not having a copy of the marking paper, that the sine bar is not "way up there" as regards the accuracy required of a sine bar nor the highest order of acheiveable accuracy for the time/period, but a good piece by an apprentice or trainee that seems to look very well and made about 40 years ago.

That seems to settle the "accuracy bit".

Others may continue to admire it for its aesthetic value and for any historic or personal aspect it may have or be seen to have.


I don't have (and neither want nor need) a standard sine bar as such but I do have "sine vises" and a sine magnetic chuck (tilting) - all "Chinese" of course - and so far as I can tell they are very good and meet my every need.

What a load of crap.
So from one photo you can work out who made it, when it was made and to what accuracy.

You must have bloody good eyesight.


For my day to day angular settings and measurements I prefer my "Chinese" "Vertex" 6 rotary table which is calibrated directly to 20 arc seconds which is very close to 1 in 10,000 or 0.0001" per inch. It is easy to interpolate it to half that at 10 arc seconds.

After working on various makes of modern rotary tables including genuine Vertex let me tell you that you cannot get anywhere near that figure and before you post the spec sheet *again* it's not worth the rice paper it's written on.

I can unpack 20 tables for conversion to stepper drive even getting them from different suppliers and guess what ?

The spec sheets are all the same, to the exact decimal place.

Are they precise tables ? No
Are they worth what you pay for them? Yes.

And after the hatchet job you have done on the OP I'll bet serious money hell will freeze over before you get a look at that sheet of paper, you'll have to draw your own.

jackary
03-24-2012, 07:16 AM
The one thing that has emerged in this thread is the passion the participants have for engineering and craftsmanship. Without this it would indeed be a dull world. I think that it shows through in the tools made in times gone by, often by unknown individuals. Their efforts to do their very best sets the bar, it is a reference level of excellence. I think that it is this what is revered and cherished.
Alan

oldtiffie
03-24-2012, 08:05 AM
What a load of crap.
So from one photo you can work out who made it, when it was made and to what accuracy.

You must have bloody good eyesight.

The OP said it was 60 years old but I did ask him for a copy of the paper to verify the date and limits - if any. The OP provided the names of the person who made it and the person who marked it.

I queried the OP's statement reagarding the level of accuracy that he stated were:


Originally Posted by uncle pete
.................................................. ...........

Then logicly the equipment and methods used would have been to the highest accuracy standards, Actual costs would have been immaterial. The 40 year old hand drawn sketch done by the original builder was included with this sine bar. The inspectors exact measurements were also marked down in five decimal places. The center - center distance for the round rolls are given as 5.00034.

......................................

I've yet to find out how those exact measurements were obtained.

...............................................
[/QUOTE]

All I addressed was the matter of accuracy and whether it was to "to the highest accuracy standards" at that time and how it might have been measured and against what standards.

Nobody seemed to want to see what those standards might have been but given it was only about 60 years ago, and to satisfy my own curiosity in that regard I set about finding what the accuracy standard are today regarding the sine bar and slip guages etc - which I did. As I recall all of that was available in use 50>55 years ago so that would have included the 40 year period referred to by the OP. It was available quite while before that too as I used it 50>55 years ago - as an Apprentice - and it was in use well before then.

I have no issue with the vagaries of what might have been as regards finish or the history of the sine bar and its maker or marker as I left that to others who were interested in those aspects.

I was more than a little surprised and disapointed at how many eulagised about the accuracy and craftsmanship without even querying it let alone running a cursory check.

I did not do a "hatchet job on the OP" as I merely took his word/s and took a further interest in them for my own interest.

I also did not say the OP was wrong but I did say that from what I could glean from what he said after I had a closer look at it (for my own interest)that in my opinion it was not as high a level of accuracy and skill as he may have thought, but that I thought it was fairly typical of an apprentice training project at that time.



.....................................
And after the hatchet job you have done on the OP I'll bet serious money hell will freeze over before you get a look at that sheet of paper, you'll have to draw your own.

I neither set out to nor did I do a "hatchet job" on the OP as you suggest.

Whether or not the OP chooses to post a copy of that marking sheet is his decision alone and I will respect him and accept that.

willmac
03-24-2012, 08:56 AM
Oldtiffie-

I would place a great deal more reliance on the inspection report done on the OPs sine bar than I would on any Chinese sourced inspection report for typical tooling. Using one of these Chinese reports to compare accuracy of tools is (in my opinion) a waste of time. I have not had the excitement of unwrapping lots of rotary tables with exactly the same reports like John S has, but I can certainly believe that this is the case. Vertex tools are a little bit better than the average Chinese products but they are by no means free of this type of problem.

A case in point was a Vertex milling vice that I bought (with the usual inspection sheet). It wasn't until I started to use it that I realised that there was something subtly wrong with it. The ways on which the moving jaw slides are not ground in the same plane. This takes a bit of careful measurement to find but is there and is outside the limits for the vice. I didn't return it because by then it had a fair bit of use and the the cost of postage was significant. Having to use a bit of fag paper for some jobs is not ideal. I will get it reground eventually. The inspection report was meaningless - just a bit of marketing crap.

I think you would be surprised if you took your rotary table to a calibration lab and asked them to inspect it for you. The kit that such labs have is way, way better than anything that we have in a typical home workshop, or even most commercial businesses for that matter. I suspect that it is similarly way better than the maker of the Vertex table had, whoever they are and I further doubt that they do a 100% inspection beyond a visual check. Calibration labs have no axe to grind in giving you the truth and I would trust the one that I have used to provide an honest report. They will usually try to recalibrate where they can, although I doubt that this would be sensible for such a rotary table.

John Stevenson
03-24-2012, 09:00 AM
I have not had the excitement of unwrapping lots of rotary tables with exactly the same reports like John S has,

Believe me there is no excitement when you know none are yours and it's all work :confused:

oldtiffie
03-24-2012, 09:18 AM
Oldtiffie-

I would place a great deal more reliance on the inspection report done on the OPs sine bar than I would on any Chinese sourced inspection report for typical tooling. Using one of these Chinese reports to compare accuracy of tools is (in my opinion) a waste of time..

Wilmac.

In regard to the sine bar measuring, I did not say I had used my own measuring equipment - which is certainly Chinese - which were certainly made a lot less than 40 to 60 years ago - which would have ruled them out anyway.

Any measuring standards used by the person who marked the sine bar were - according to OP - in the USA and perhaps at the Palo Alto laboratories - and from his description of them would have been NIST calibrated and certified.

Any that I used all those years ago as an Apprentice were the UK/AU standard NATA certified slip guages - NIST standard in the USA - so the Chinese slip guages were neither around then not were they certified then.

So my stuff was not and is not an issue.

I did not say that my Vertex 6" rotary tables were to laboratory standards - only to my requirements - and those rotary tables met and still meet my requirements in every way.

I have several "Vertex" vises and while they are not perfect I know and use the required "work-arounds" to largely cancel or negate these issues so all is well and within my requirements.

John Stevenson
03-24-2012, 10:55 AM
I did not say that my Vertex 6" rotary tables were to laboratory standards - only to my requirements - and those rotary tables met and still meet my requirements in every way.



You must have higher standards then than most laboratories ;)
Interesting to know how you can measure to 0.00005" ?
Must be a very, very accurate crayoned drawing ?




For my day to day angular settings and measurements I prefer my "Chinese" "Vertex" 6 rotary table which is calibrated directly to 20 arc seconds which is very close to 1 in 10,000 or 0.0001" per inch. It is easy to interpolate it to half that at 10 arc seconds.

oldtiffie
03-24-2012, 11:43 AM
As you were even good enough to say that I said:


Originally Posted by oldtiffie

I did not say that my Vertex 6" rotary tables were to laboratory standards - only to my requirements - and those rotary tables met and still meet my requirements in every way.

and:


Originally Posted by oldtiffie

For my day to day angular settings and measurements I prefer my "Chinese" "Vertex" 6 rotary table which is calibrated directly to 20 arc seconds which is very close to 1 in 10,000 or 0.0001" per inch. It is easy to interpolate it to half that at 10 arc seconds.


It may assist if you read them together.

John Stevenson
03-24-2012, 11:54 AM
I did and read that your requirements were for 0.00005" accuracy.

Show us something you have made to this accuracy, better still just show us something you have made.........