Accuracy of Antique Test Indicators
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- เผยแพร่เมื่อ 28 ก.ย. 2024
- Comparing the accuracy of an old indicator with JO blocks.
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Another great video Mr.P!
Thanks
I love the history. It is important for all of the current CNC guys to understand how we got here. Things used to be done on paper with pencil and slide rule, not CAD/CAM and CNC... I was sad the day my Grandfather died because he had lived from the age of the horse and buggy up til the Space Shuttle... To have been able to see the change that took place in just one man's lifetime... So thank you for sharing the history, it is very important!!!
Thanks for dismantling the Ideal indicator. I've got one of the type over here in the UK, it very dirty and 'stuck', so soaking in a sealed jar of brake cleaner, think it might be a Starret. I now know what to expect when I strip it down. My plan, assuming I can get it to work, is to check the run out in my lathe on set up so really using it as a comparator, accuracy of measurement is not important. As always a fascinating project with history lesson thrown in for free.
I did my required reading Mr Pete. I found both pages very intresting. So many good links to click on and read. I bet Wikipedia have noticed a large spike of people viewing those pages thanks to you. We had our Apprentice Training Master, Mr Ray Benson. (In Australia trade called "Fitter & Turner" ) You remind me of him.. Thanks.
Thanks 👍
Great knowledgeable video! Just found it interesting and watched and learned something new! Thumbs up! Laughing at, whoops there goes the needle! Good humor!
Lyle, Here's my vote for more technology history! I find it fascinating too.
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I really enjoyed your Video on Carl Johansson. Thank you. I felt that I was right back in shop class oh so many years ago. I can still see my shop teacher, and I sware that I heard his voice when you gave out the assignment. I did both assignments by the way. I am anxiously awaiting your follow-on using calipers.
Thanks Again
Gary 75-Year-Old Home-Shop-Machinist in North West Arkansas
When you place the Jo-Blocks under the Ideal, the whole unit looks to flex on the close-up video, as if the mount may be loose. The thicker the block, the greater the deflection seemed to be. I think the accuracy of the unit itself was okay. With a couple of Last Words, the Ideal is redundant anyway. Keep 'em coming Schulmeister!!
I can't research Carl Edvard Johansson , the dog ate my internet
lol
Get your dog to vet, I hear the Internet can be toxic. :->)
The dog ate my algebra homework once,it looked like someone took a pair of pinking shears and went all around the edges! My proper type German algebra teacher still accepted it because all the work was readable. Although he wasn't pleased!
MR Pete.... I do enjoy your historical inserts, books, people etc... our machinist history is terrific. Thank you.
Thanks
I am amazed where you find all these old instruments let alone the time and work you invest into a video like that one, actually all your videos. Thanks, it was very informative. This must have been even before my time.
Thank you Bob. And yes it takes a lot of time. I probably average eight hours a day. Keep watching
I have a test indicator that at first glance is a duplicate of the Ideal indicator. Mine is British made and has a cut-out window so that the indicating needle doesn't have to be split. It has a 0.015" range. One side is graduated in Imperial and the other side is metric. I've found it to read accurately across it's range.
I've had the indicator over 50 years, but rarely use it. Test indicators like the Starrett Last Word are more convenient to use.
Tolerances and accuracy from 1900 are still usable today. But the metrology advances made between 1900 and today are almost miraculous! It's so cheap to measure accurately now, but machining to what we can measure is still expensive, or time consuming...
More than 3 digits to the right of the decimal is getting into the noise. I wonder if kids nowadays learn about significant digits anymore? I was trained at the end of the sliderule age, and significant digits were hammered into us at every turn. Even after calculators were affordable.
Yes we do..... weekly rent and student debt costs more then the highest significant digits provided in a wage slip.
Not quite where I was going, but accurate non-the-less! I like the wit! It's not just for students, tho. I've been out of university for almost 30 years now, and my stagnant wages don't spread as far as they used to....
I was aiming for this: th-cam.com/video/5UjwJ9PIUvE/w-d-xo.htmlm8s
@@stxrynnWhat? Everyone knows that the circumference of a circle with a diameter of 10 inches is 31.415926535897932384626433832795 inches, not 31 or 31.4 Who are you trying to fool?
But yeah you'd think NASA would need some hairy accuracy when plotting a course to Mars, but no. they use 3.14
@@ExtantFrodo2 I don't know about that, their 1960's engineering stress and deflection software we used(NASTRAN) usually went out 6 decimals.
@@bcbloc02 ...because those were not insignificant in the employed metric. Right? Plank's constant has significant digits out to 10^42. Atomic force microscopes detect deflection's in the picoNewton range. It doesn't change what I said about calculating a trajectory to Mars.
These videos on accuracy among the most important you have ever done. Understanding the mechanics of accuracy is essential to consistent production.
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Great class today Mr. Pete! Everything you said wrings true!
lol
Love historical connections! Thank you, Professor Peterson.
Love the history lessons added to the end. Try and learn something new every day
Thanks
We in switzerland appreciate the attention to real world engineering. Love you tubalcain!!!
ok Mr. Pete, we know that you never throw anything away. LOL. When I was working, we just bought new gage block sets that were Chinese made as it was far cheaper to buy new ones rather than pay for calibration. At the time, 6 years ago, you could buy them on sale for under $ 100.00 USD and they came with certification. Good to see that you moved the gage blocks to the indicator as you never move the indicator to the piecework, also do not moving directly towards the indicator stylus, but at a sideways movement, or from the hinge side. there is less chance of ' bouncing ' the set up. Lever indicators were never meant to check multiple heights, only used for repeatability due to cosine errors. You need to get your hands on an Interapid or an Alina .0001 indicator if you can. Then you can have some real fun with testing. have fun !
Thanks. I think I have an interapid
Hello MrPete Greetings from Great Britain. I have a set of the Johansson Ford blocks in Original Bakelite box. Keep up the great videos,and look after your self.
👍👍Thank you
If you look very carefully at the tip of the Ideal indicator as you put the blocks under it the body of it moves upwards very slightly. I'm watching on a 37inch monitor btw.
I will have to look at it on my 55 inch TV
He's got the last word lol
Love hearing the history behind the tools.
Thanks
Love the old tools got a few some older machinist gave me years ago . Going to make me a shelf and display in the shop.
Think these antique tool are awesome . Great video Mr. Pete
Watching in Alabama!
Keep up the history lessons and the care tips, Lyle. Thanks.
Thanks
Thank you Mr Pete.
I have a partial set of miss matched gauge blocks and there are some with Johansen, Ford and Brown & Sharp. I also saw the calibration video that you mentioned.
Interesting.
It is always fun to see the history of things. I liked seeing the Ford logo as well.
Thanks.
Thanks
The primary pivot shows considerable slop, indicating it is severely worn thus causing the error measured. A challenge or the old eyes would be to manufacture a new bushing to restore it to useful condition. I'm seventy four and have several magnifying devices for the times I stupidly try something like that (lol). Love your videos. From "downunder".
Thanks
Thanks again for another great video. I wish to take exception with one of your statements. When you started to disassemble the ideal indicator you said,"this is a job for a jeweler." I think you might have met a watchmaker since jewelers make jewelry and for the most part do not repair watches or other small instruments. I hope that no one thinks this is too critical since I love watching these videos. Paul.
I like the history. Keep it up.
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You can take the teacher out of the classroom but you can't take the classroom out of the teacher, most interesting. Thanks I enjoy the historical sections very much.
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Great Video Mr. Pete !!!! Love The History !!! It Is Well Known That The Ideal Company Knowingly Hired Several Rabbits With Saddle Bags In The R&D Department Starting Around 1903 .
lol
Sir, i have to introduce a youtuber name Uri Tuchman, he just hand made a similar indicator, he is kind of a middleage craftman more than a 20 century machinist. With some crazy details on simple items and educated twist humour that can make you laugh, definitely worth looking. Don't miss that guy, he had skill, humour and some diy power
Thank you, I just watch the one on the indicator. Then subscribed. I have a little trouble understanding him. He is quite an artist.
That photo of you and Tom is gold. I might just print it out and put it on the wall over my lathe.
Thanks
Love the history. I have the ford blocks in a bake-alight case.
Mr. Pete, The question you asked about combinations is, like all easily asked questions, quite complicated. I’m not a machinist, but I own a farm and a few math degrees (and I’m hooked on your channel). Combinations suggest that order does not matter, 1.000 + 0.001 is the same as 0.001 + 1.000... Not sure, but I suppose, practically these are equivalent when combining Jo Blocks. But since each block has two “faces”, there are four configurations to wring two blocks. Then if the orientation matters (rotate each block 180) then there are eight (or 16?) configurations to wring two blocks… ugh! OK, let’s assume, the “cow is a perfect sphere” then if there are 81 blocks in a set and one can use all of them to create “a width”… the possibilities are huge! The math reads- n! = 81! = ~6 x 10e120 (big). If you typically use two at a time to create an accurate width, no repetitions and the order of wringing matters (permutations) the selection reduces… the math is n!/(n-k)!. n = number of Jo Blocks, k = how many you use to create a “width”- 81!/(81-2)! = 6480. One more, if we go “simple” and say something like, “81 blocks available, pick any 2”, the “combinations” (no repetition, order doesn’t matter) reduce further. The math is n!/(k!(n-k)!) = 81!/(2!(81-2)!) = 3240. 😊
Thank you, that is an interesting observation. In a future video, I will show the doall Book. The book lists the 10,000 possibilities for stacking the blocks up to 1 inch. Using the 81 block in the Set. Also possibilities if you have more than one set. The book is 3/4 of an inch thick
I saw an old article in Popular Science that showed how to make an Ideal type from scratch
Neat
There was also a project in a book for the Unimat for a similar indicator. I made one, but it's good for relative measurements only (the cheapest dial indicator is more accurate).
Lyle I have a Ideal indicator too, don't have the holder but I rigged one that works. and I checked my Ideal against a Last word. Works great.
The ideal indicator housing is flexing upwards when you slide the larger stacks in, I bet that's where you're getting your 1 to 1.5 thousands error - flex over the length of the housing. Great video as always!
Yes
I always understood that the last word style indicators are a comparator and are not really to be used as a direct measuring device as since the stylus moves in an arc and not a straight line there always will be some error due to the arc motion being translated to a linear movement.
I like Maudsley's name for the bench micrometer he created (one of the first micrometers to measure to tenth thousands of an inch) in his shop, "he called it the "Lord Chancellor", as it was used to settle any questions regarding accuracy of workmanship." The Lord Chancellor being a member of the English government and head of the judiciary.
I never heard that before, I love it. Most appropriate
Lyle, very nice !! Thanks for a great watch, Cliff
Thanks
What a coincidence, I have Single Ideal Test Indicator in the original box! Of course what single means is that the needle and graduations are on one side only. This indicator came with a 0.250 by 0.500 mounting bar and nothing else. Maybe this video will get me to test it and perhaps make some other ways of holding it.
Love it Mr Pete
I have one of those Ideal indicators, came in a used tool chest I bought. It was a rusty mess, soaked it EvapoRust, cleaned up OK a little sticky though, may have to take it apart. Why do gauge block manufacturers always use wooden cases, you'd think they would know better? Good lesson mrpete!
I hope you're ok after the Harbor Freight visit. ...?? I go there occasionally. I like to look around. Once in a while I will buy something. I assume you exchanged the first caliper...
Thanks again for your great knowledge. Really like the historical significance of tools. Amazing how many tool manufacturers there are.
12:43 the ideal is moving under the .010 load, part of the lost distance there.
Great video Mr. Pete....you mentioned not storing tools in a wooden box. What is the reason that many tool makers have a Gerstner chest? I built boxes out of walnut for storing my grind vises and spin fixture. I put piece of camphor in the boxes and it seems to keep things from rusting. Keep up the great videos!
I've got an Ideal indicator, strictly as a souvenir and never took it to mean thousanths, simply a relative indication such as for centering. Seems to me it could only be calibrated by reworking the probe tip to alter the effective length and so...nah.....No wait - make an overlay for the scale. Great piece of old tech though!
Went and read both articles. Now waiting for that extra credit..
lol
I’ve come across this video 4 years after publication. I wonder how accurate this mechanical indicator is if used as a plus or minus gauge using the .005 as mid range and using it that way. In reality when an indicator is setup it is setup in such a way that you can measure high and low side of tolerance not just the measurement you’re trying to get to. That is if the indicator has the range, but certainly this could work if your tolerance is plus or minus .003? It would be nice if the video showed that as an example as well.
"Properly wrung blocks may withstand a 75 lbf (330 N) pull. While the exact mechanism that causes wringing is unknown" It boggles the mind that something so simple is still unknown!
G’day Mr Pete, the Ideal was not so Ideal but I’d still like to have one
Cheers
Peter
"You must never store things in a wooden box" - Next scene - Fowler (wooden box) holding gauge blocks. :) So my questions are
Why are so many tools sold, stored in wooden boxes?
Is that the reason for lining with felt?
Love your videos and you may "wander" as you will. Usually always learn something when you do!
I knew it!!!!
I knew it!!!!
Also, some wood contains acid, which is not friendly to measuring equipment also.
@mrpete222 I think the video you referred to on gauge block calibration is here: th-cam.com/video/mKzFXJCryrU/w-d-xo.html This is a tour of A.A. Jansson and it shows the entire process of certification. This video begins with the history of the company and the development of gauge blocks in general.
Another informative video, THANKS! The set up did with the IDEAL might not be ideal. You might get better results if you think of the 5 on the indicator as your zero. In effect preload the mechanism. Then change blocks to add/subtract up to .005 That might (should) yield better results. I would never trust test or dial indicators for anything but "relative", and that means start in the middle. Long winded 2 cents worth.
I saw a starrett last word branded version of the lever type, still in its case, no idea how old it was or how accurate, but it did still work.
THANK YOU...for sharing.
I can see the "Ideal" indicator moving slightly during the tests. It is very subtle and you have to look very closely, but it could be roughly 1/1000th of movement (one pixel or so on the screen). I think it is a lack of rigidity in the setup allowing for this. I bet with more rigidity it will indicate dead on. Great video, thanks!
Yes thanks
I like the video. Just one question for the teacher though. Having seen the inside of this indicator I can't imagine how it has become inaccurate. Do you have any ideas about why it reads .001 fine but .010 is off?
I'd guess it was never quite accurate in the first place.
I can't say for sure but it looked like the tip on the Ideal indicator, was not centered and off a little. Maybe if the tip was inline with the holder it may have given a better reading.
Mr pete thank you for you time and sharing your knowledge. I think the indicator that was not reading correctly was set up at an incorrect angle. If the angle is a little steeper it should read correctly. i would like to know your thoughts?
I did the required reading. Good video!
Sometimes imagination capture our mind. And i can only imagine what that ford stamped blocks or bs were used to measure or build. And who were the men used them. That's why sometimes is better to collect something instead throwing it away.
Yes
Like the historical sections!
Thank you for the lesson! It’s always good. How close are you to finishing the little steam engine? I find that super interesting and watched the other wobbler videos you have made! Keep up the good work.
Is the economy grade or B grade JO blocks good enough from most work? And if you buy used set what do you need to look for and how do you take care of them after you buy them?
Put it in a cup of naptha to clean it, oil lightly, re-assemble and test again.
For a typical 81-piece set, it's 2,417,851,639,229,258,349,412,351 combinations! for a 36-piece set we have 2^36 - 1 = 68,719,476,735 possible combinations.
www.practicalmachinist.com/vb/metrology/there-algorithmic-description-stacking-gage-blocks-323218/index2.html
Holy mackerel! Thank you
Someday if possible could you explain what does tool makers standard mean in regards to tools or is there such a standard. Thank you so much.
???
It is a "standard" to which other items are compared. So you check your caliper, micrometer etc. against a known reference e.g. a gauge block.
Search wikipedia for " Standard_(metrology) "
"Rewinding" the video a few times after you opened the case, you can see there is wear in the pivots as the indicator point/lever was actuated. Just send it back to the manufacturer for repairs. lol. Imagine locating a replacement spring and then replacing it? Delicate and crude but, it worked. Nice relic.
Mr. Pete,
Could you talk about the various grades of gage blocks. What grade will work for the home shop?
Would be interesting to see how the DRO on your mill compares to the indicators.
I'm wondering if you had some cosine error when checking the Ideal. It seemed to me that you could not get the stack of gauge blocks under the pivot (unlike when checking the Starrett). This put the sensing probe nearly level. I have always understood that these lever-style indicators (both pointer and dial) should have the probe angled down enough that the tip is below the level of the pivot housing - typically about (edited from 27.5) 22.5º (half of 45º). The Starrett was angled down about that much as I could see that you could pass the gauge blocks under the pivot housing on several occasions.
You could try that again on the other side I think if you look at the tip you will find one side is no longer round and since the unit read low at the top of its range I'm going to guess that the back side is slightly flattened do to wear and not being round is the number one reason to reject
Good idea
Very informative as always. p.s. I hope you cleaned that Ideal indicator before reassembly. It sure looks dirty.
With the 1.04 it does not go to 0.04, cause the whole indicator lifts a bit :)
I would only ever use them as a comparator.
Good interesting video.
What kind of effect would wear have on the indicator?
I'm assuming it would slowly diminish/divide the recorded measurement as the contact surfaces wear away from one another.
The Ideal is old and the pivot point is worn. I doubt that jewels were used in its manufacture. The most common area of usage would naturally be somewhere in the middle of the scale. That put all the wear in that area of the pivot points. Imagine someone letting the lathe spindle run while checking run out of workpiece.
Great analysis
The Ideal gage while inaccurate could still theoretically be used to check runout or vise alignment since the target measurement is "zero" as long as the needle has close to zero back lash. Obviously the modern jewelled indicator is the way to go I wonder how accurate a brand new ideal gage would be, since they no longer exist as "new" I suppose that will remain a mystery.
Yes
Full number is 2 to the power of N. N being the number of blocks. Although this would include no blocks.
Thanks for sharing sir..
When you took that unit apart you can see how poor the pivot screw fit is so no wonder it is off.
More like This Old Tony Indicators.
That indicator would be "Ideal" for my 1894 Barnes 4 1/2 Screw Cutting Lathe...
excellent video!!!
Suburban tools: A.A. Jansson Field tripp.
I would assume that one that measured in angstroms would be called The Gospel indicator. LOL.
lol
The reading depends on the angle of the indicator due to cosine error. If you set the ideal indicator at an higher angle the reading shuld get better.
Correct me i’m wrong.
Should*
GREAT VIDEO !!! HOW ABOUT A STARRETT # 564 ?
I rarely argue with Mr. Pete, but I don't think it's really a fair test. You can see the housing of the indicator move as he's inserting and removing the gauge blocks from under the tip, especially at the .008 and .010 test marks (th-cam.com/video/P1zZRJmvtJQ/w-d-xo.html). I'd wager that with a more rigid fixture, it would likely be more accurate, but I accept that the mounting options designed into the indicator probably contribute to the error, and would take considerable effort to solve.
Nice demo, Now calibrate the Ideal.
First and first, another great video. I’m sure you’ll get it back together, but can you calibrate it?
Thanks
Hey Mr. Pete. One of my old Granny's favorite jokes was... How do you get down off an elephant? You don't , you get down off a duck! I think you have to be at least 50 years old to get that joke.
lol
this indicator can be made at home yourself, I did it myself when I needed to measure the curvature of the mower's shaft :D
Thanks
Good morning. I do hope you are staying warm!
Isn't it possible that as the tip of the indicator rises to a certain height, a cosine error is created?
I think the whole thing and flexed
On the Ideal indicator you may be correct but I was also referring to the Last Word indicator as well as it uses gears which is indicated by the .0002 error.
Either way, thank you for posting and stay warm.
I like to throw desiccant packets in my machinist tool box drawers to keep ol' rusty away.
I didn't dose off in class. I like history. As far as assignments, that's a different story.
lol