Max Maker The difference is that Mitutoyo knows they're the best, with Starrett and B&S. They don't need to sell things, they just need to make sure you get what you need or at least things that might make your life easier. It'd be much different for a newcomer to try to convince you why their product is better and cheaper, without the reputation to fall back on.
The company sales people and many of the technicians know very little about the application or worse your application of their technology, but the big names have put in the most work figuring this out. Be prepared to pay for it. Mitutoyo and Brown and Sharp/Tesa are really in a class of their own.
Mitutoyo calipers can be considered among the best. Mitutoyo micrometers have a HUGE flaw by using flat standards. I wrote up a article on the errors from using a flat standard on a instrument that is made to check round parts. Im not nesc knocking Mitutoyo, just be aware that in critical work Starrett is king for mics. I do prefer Mitutoyo calipers over Starrett though :)
Jeremiah, you can always get round end standards if you are really worried about the accuracy in certain specific situation. And those mics? They are not "made to check round parts", they can be used for nearly anything.
I use Mitutoyo Micrometers and Calipers everyday. They are my personal tools and I make my living with them. Thank you, Mitutoyo, for making excellent tools.
Hey John, Congratulations you are heading into the very interesting world of metrology. Your ability to make things is directly related to your ability to measure them. So your measuring has to be better than your manufacturing abilities. On your gage blocks. There are wringing films on the gage block surfaces. These can contribute significantly to total gage block stack errors if not done correctly. In fact the published length of a gage block includes one wringing film as if it was wrung to a measuring platen. "Metrology, Its a dirty business" (Oxtool quote) Talk to you soon, Tom
oxtoolco, I agree, but John missed thermal expansion. Robin Renz in one of his videos where he had setup your gauge block he restored, you can clearly see just from the heat of one finger move the indicator. I think it's something we should all be aware of like cosines and abbey errors. Quote: "Any measurement that you make without the knowledge of its uncertainty is completely meaningless." Professor Walter Lewin, MIT
MrVajutza, I think this is more of a general introduction. If we were going to get picky we would address using a flat standard on a mic(big no no because of surface area/pressure) and also calibrating the mic to the position it will be used in because of gravity's effect(more critical on large mics), thermal expansion, etc. This is a great video to familiarize people with metrology. Good job John, and keep up the great work!
The notch on the end of the caliper bar is to let you measure depth even when there is a slight radius at the bottom of a hole. Source: A friend of mine in R&D at Mitutoyo.
On the topic of metrology and gravity, I once worked on a part for a hydro electric dam. It had a 24 foot inside diameter that needed to be measured with an inside micrometer. In order to compensate for the sag of the bar micrometer, it was calibrated on a laser setting device while being held only on each end of the bar. When measuring, the guy on each end had to hold the micrometer in the same spots the calibrating machine held it. Temperature differential between the part and measuring device also became a big factor.
Welcome to the land surveyor's world, at least the world before lasers. You used a steel tape to measure distance. A 100' chain (tape) was good to a small fraction of an inch. IF it was level, and IF it was pulled to the right tension, and IF it was held correctly at the right points, and IF you measured the average temperature of the tape and applied the right compensation factor.
I always heard "measure twice, cut once". Which is great. But then a machinist colleague told me "cut twice and it's still too short"...that definitely changed the way I think about metrology.
John I just got up and went and opened ALL my thimbles and caliper jaws Thanks so much for the tips and all that you do for us out here in youtube class!
Love this one, definently want to see more of this. I've heard people say "If you can measure it, you can machine it." I'm not sure if that's strictly true, but no doubt measuring is the cornerstone of getting it right.
Great vid. Even as a professional machinist I learned a few good points. It's funny that I've always stored my micrometers like that too, not because anyone told me, but just as a general observation of storing integrity dynamics. Glad to know I have not been overly paranoid all these years.
I've got a 0-1" Quantumike and I later bought a 1-2" Quantumike. I love them both but find I don't need to use the 1-2" one nearly as often. To get consistent results you still need to develop a feel for the speed and force you use to close them even with the clutch. I also have a Mitutoyo 6" caliper that I carry around with me most of the day. I recently got one of Shars Aventor calipers for home and I'm really impressed with it for the price.
I am quite surprised that there was no mention of thermal expansion difference between steel and ceramic regarding the gage block demo (also carbide gage blocks). If your shop varies in temperature it is best to measure with as close of materials as possible (obviously no such thing as aluminum gage blocks of course) and the rate of expansion between ceramic and steel is different enough to cause issues should you be measuring at a temperature in which the part is not expected to operate. Dedicated inspection setups generally require a minimum of 24 hour temperature normalization in the same environment in which the gages are kept and then certified that they have been inspected at that temperature.
John its Van der Waals force. The blocks once the air between them is removed stick because the materials contact so effectively. Same forces that drive capilary action and what sticks Gecos to walls. If two surfaces of pure metal (unoxidised) are placed against each other and they are PERFECTLY flat they will weld together. They will become one piece of metal. Most metal has at least a one molecule thick layer of oxide so this is very rare.
A friend of mine used to work in aerospace and he told me one of the challenges was that in the vacuum of space the high quality gold pins in multi-pin connectors will weld themselves together, therefore they need to be gas purged in order to prevent this from happening. I think it is known as cold-welding. Not sure if this is the same as Van der Waals force, but non the less an interesting challenge if you are building space-craft! Great video John. Thanks for this. I am surprised Mitutoyo do not have a video series on RUclips themselves. They are missing a trick there!
Well.... mysterious-er and mysterious-r! So it seems the fact is nobody really knows......can you believe that!? We humans have a lot still to learn. (Me especially)
While that PDF sure has a great intro this one mentions the oil films with some extra details: www.starrett-webber.com/gb46.html i.e. "[Step] 2. Wipe the surfaces of the blocks to be wrung gently across the oiled Wring Pad. " and "Gage block length is defined as an interferometric measurement when the gage block is wrung to a flat platen. This includes one wringing film in the defined length of the gage block"
It has little, if anything to do with Van der Waals forces, it’s merely atmospheric pressure pushing them together due to the fact that the air between the two smooth surfaces has been displaced. The only possible Van der Waals could be what is known as a London dispersion force which is a very weak type of temporary and spontaneous attraction common to all molecules.
John in my high performance engine machining class we learned to check parts by pinching the jaws of the caliper to the part instead of using the plastic or wheel. reasoning is you can't flex the caliper if you pinch at the contact point to your part.
Hi John About micrometers, the salesman from mitutoyo talk about the important thing to remember. allways keep the surface clean. He only talk about calipers. After few measurements with micrometers, and the contact surface is not clean. Just use a copypaper, and turn it so it squeeze on the paper, and then pull the micrometer away from the paper. Now you have a clean contact point
Good stuff. This Old Tony did a video explaining cosine error recently. The sleeve trick is good, but be sure not to run it all the way down. Don Bailey over at Suburban Tool has a good video about micrometers.
steel gage blocks should be cleaned with block cleaner and stored with block preservative as for ringing, you are removing the air between the blocks which causes a sort of vacuum " 1. Air pressure from the surrounding environment as the air is squeezed out when the blocks are slid together. 2. Surface tension from oil that remains on the gage blocks or water vapor from the air acts as a glue to hold them together. 3. When two very flat surfaces are brought into such close contact with each other, this allows an interchange of electrons between the atoms of the separate blocks, which creates an attractive molecular force. (This force will remain even in a vacuum or if no oil or water is present on the blocks.)
That clutching mechanism on some micrometers is for those who cannot measure by feel - sometimes measuring is an artform too. Also, gauge blocks are for those who don't trust their micrometers' or gauge. Let me know if that last sentence was grammatically correct.
In your metrology room, keep a stable temperature. don't hang onto the block for too long because they will expand (esp. small ones) beyond their nominal size. IIRC the correct temperature is 20°C but skin temperature in your hands is closer to 32°C.
I am not sure but I think the notch at the end of the depth bar is because a lot of parts have little radii between the face you want to measure and the wall the measuring tool is resting against, so that notch keeps the radius from interfering in the measurement. That's my theory at least. Cheers
Hi John. AVE did a good video understanding 'ringing' gauge blocks. Well it was good for beginners like me. Wonder if it would be cool to do a live Q&A session with Mitutoyo? Just a thought! Kindest regards. Joe.
Wringing is caused by van der waals force. The molecules are attracted to each other, although normally not noticeable because the contact between two less flat surfaces is much less and it is a relatively weak force. With two precision surfaces there is enough contact for the force to be noticed. If the surfaces were flat enough, a covelant bond can be achieved and the 2 pieces would become one and not be removeable again. The "gravity" trick at the end is... flawed. Your test indicator is picking up mostly compliance in your indicator stand. If you had it fixed with something more rigid and stronger than a magnetic force you would see considerably less. The pattern maker of your parallel mentioned accommodating for gravity because of airy and Bessel points. They are essentially calculated points of where to support a beam to either have the ends parallel (airy) or top and bottom average the most parallel (bessel) Cool stuff!
I was always told the wringing is helped by the lack of air pressure acting on the two flat surfaces since they are in contact so closely there is an absence of air between the mating surfaces. I also understand the sharing of Electrons is another theory....
How about testing the indicator theory of yours first before speaking out loud? Doesn't matter if you have a magnetic stand or not, the linkage & indicator will bend under gravity and is the reason why you shouldn't use them on a horizontal machine.
Hey John, You asked a question at 18:23, but did not answer...editing mistake or intentional? I also agree with comments below ONE CAMERA would make it easier to watch.
I subscribed to their channel after I saw it on your Instagram. Not many views but good info. It's a shame they don't have more subscribers or views. It's great to see your shop in the background of their videos. Really great tips. Thanks.
Martin Maurach True. But the minor extra cost for it is so worth it, specially with tenths read outs. The extra $10-$20 extra is a no brainer when you're dropping $150-$200 on a mic
I would rather not fiddle with a mic anymore than I have to. So I am all about the friction thimble! Plus, they are so dang cheap now, how could you not buy one?!
When verifying micrometer calibration I always do 0, 1/2, and full open Using gage blocks or standards. If you don't do that you can't trust the micrometer as some mics will have variance in the readings do to inaccurate or damaged threads and this will not show up by merely zeroing out. Indicators like the Interapid and Last word are intended to be comparitive reading tools and not actually measuring devices. As such there is no need to worry about cosine error with them as the measurements are always comparitive and not actual.
Because it is all you really need, and measurements take time. You could probably get away with 3 positions. The major error that you are looking for by checking different angles is not thread error, but the faces not being exactly parallel to each other and perpendicular to the screw axis.
I would never suggest using a gage block to calibrate a OD Mic. Do this little experiment and you will see why...calibrate your mic with a radiused standard or calibrated gage pin. Next get a calibrated gage block and measure it. the Micrometer on average will mic a flat surface .0002 larger. Starrett says on average its .0001 but I have found it to be closer to .0002. This can be huge in real job shops where every job is different. In our area (houston) many of us work with extremely tight tolerances and can not afford to have deviations at times that large. hope this helps!
Love the information and videos. Always learn something, even after 20 plus years of machining. Wish this video showed a more close up and detailed view of the measuring techniques you use. Thank you, and I appreciate your time and effort explaining difficulties and solutions to what seem like easy answers. I'll stay tuned for more knowledge and help you provide. Thanks again , Michael
How does the Mitutoyo LH-600 compare to a traditional CMM or a used Faro arm? The costs of a CMM are higher, but the linear height gauge looks a bit limited in comparison. For practical matters, does the linear height gauge get one most of the way to what a CMM can do? Thank you
Hi John, next time you talk to Mitutoyo ask them why they don't make a digital caliper with the display facing the top so you can read it while measuring parts in the lathe. It would sure beat having to stick your head in the lathe to see the display!
Most everyone I've seen do manufacture what are usually called "left handed calipers". Makes it easy to see, but I ditched them after a week as my hands and brain just didn't want to learn a differently working tool.
John, This was an awesome video. Special thanks to you and Mitutoyo for sharing all the info. There is so much to learn about metrology but so little information like this out there. Keep it coming.
I'd like to see Mitutoyo demonstrate their 050001 Caliper centre attachment. I've got a pair for accurately measuring screw hole centres, but just don't trust them.
Awesome vid. I used mics when I was a noob machinist in the 90's and I use calipers all the time at work for modeling things but this video was a nice reminder of the correct way to have repeat-ability. LOL, why do I love this stuff so much? Damn right I want to see more.
Great video! :-) May I please ask what you do to take shrinkage and expansion into account when temperature changes? If you have ceramic blocks but are measuring steel in the summer at 118 deg F and later in the winter at 78 deg F?
Thank you John, this is some of the best stuff I've seen for a long time. Many tips and tricks for us new guys to machining and measuring. Excellent. One thing you did not mention with respect to the pressure on calipers; one should practice and develop the feel for correct pressure by repeat measuring gauge block and gauge pins. Stefan Gotteswinter has demonstrated the gravity effect in one of his excellent videos. His is the only mention of this I've seen before. Boy that Mitutoyo guy was nervous when you flapped that stack of gauge blocks around, he was following your every move. LOL Keep up the good work
@NYCCNC The answer to 18:21: On my old Mitutoyo dial calipers it's obvious - the bar has a "b" profile, with a square bar running down the channel and a thin tang to cover the rack gear next to the channel and keep the shop goo out. The thin tang is cut off about .23" from the end, leaving just the square bar. Digital calipers don't use a rack gear, so the bar can just be a rectangle for stiffness, but they cut the end down to fit in smaller spaces - and just kept the offset style of the manual calipers for aesthetics (and also probably the simplest to machine).
I think, because tthe round surface 'point' has, essentially, infinite force at an infinitely-small contact', it will always be subject to an indefinable compression, thus having a length that varies with pressure of the measuring device; this effect is also observed in kinematic mounting systems, which demand very hard 'balls' for location points.
It's from Latin. Anything that ends in 'us' has a plural ending in 'i' - for example Radius / Radii - fungus / fungi. Unfortunately not all words ending in "us" are Latin, and therefore as a rule it is not terribly useful. But your-man from Mitutoyo is correct. It's styli :-)
What is Mitutoyo doing to stop the fake Mitutoyo manufacturers? I buy used tools mostly, but Mitutoyo is one that I won't buy because there are so many fakes out there that I don't want to pay $100 or $200 for one and find out that it's a fake.
Gage block adhesion after the air has been pushed out of the way,is due to the electron's around every surface atom switching place's with the atom next to it .this is called the Van der Waal's force, they don't have to be the same material's to do this they just need to be very flat .the closer they are the more electron's may jump from one atom to the next . hope that helped John.
John, no need to feel bad about not understanding the physics behind wringing gauge blocks... I've done a lot of research on wringing and as far as I can tell, nobody has proven how it works! It's definitely not "wringing the air out" and atmospheric pressure pushing them together, I've seen blocks wrung together, then put in a vacuum chamber and they still hold with the same force as they do under atmospheric pressure... My guess is Van der Waals forces - They're so flat that they end up working like gecko feet on a macro-scale... Whatever the explanation, it's one of those that I hope is figured out within my lifetime! lol
Just wanted to add: the rabbit hole goes a whole lot deeper. Mitutoyo needs to measure their own measuring tools. So they have their own primary reference. Which in itself is probably referenced at your national metrology institute at their secondary reference. They intern will use a primary reference (our primary weight reference doesn't leave its vacuum chamber but twice a year). The national primary reference will be sent to Paris, France ever so often. So see if you can visit your national metrology institute. www.nist.gov/iaao/national-metrology-laboratories
John, When you do an advanced video, can you include the error caused by holding a micrometer in your hand too long? When I looked it up, I stopped resting my mike on the manual lathe because of thermal expansion.
Measure Me: I bought a _Kennedy_ 9.00mm (0.3543in) gauge block, measured with three different mics, it only deviated by -2µ. My _Kennedy_ 3.50mm (0.1377in) gauge block only deviated by -1µ which is meggafabtastic💨accurate. I used a Mitutoyo, Moore & Wright and Linear mic all calibrated at 20C degrees to be B💥NG on. Instrument le Grande: My Mitutoyo mic is superior quality and accuracy, reading down to 0.001mm (1 micron) which is pretty C⭕⭕L for a mechanical mic. The Japanese have sure got engineering down to a fine art. If it says "Made In Japan" on it, you _know_ its going to be great!...Now I'm off to peruse Japanese gauges on eBay...excuse me...👀
Cody's Lab covered this exact question about what makes the guage blocks stick. ruclips.net/video/jNEvS_bjKIo/видео.html I thought it was the vacuum created by pushing out the air. Cody showed the truth of that hypothesis. He's got a cool channel has done things like measure that pressure or force light generates.
My Teacher (Boss), when I was learning my Tool and Die maker trade, (way before I became an Engineer), set my mind in motion regarding precision, and measurement, and would scream at me for using a caliper for anything less than +/- 0.010" (Use a micrometer, he's scream, and 40 years later, it is still valid.
The best way to challenge a measurement systems rep is to run a type 1 MSA (consistency test) on a measurand you supply. Have them take 30 repeat readings, then generate XmR charts with Probable Error (PE) and Cg, Cgk output test indices. Also determine the Bias of your checking against a known standard.
13:47 its called Cohesion........the surface is so flat, that the atoms come so near together, that they stick.........nothing with vacuum or dump xD ........... see: en.wikipedia.org/wiki/Cohesion_(chemistry) if u leave steel gages connectet for a week, they probably will be cold welded by diffusion....
I own 2 mitutoyo calipef 500-752-20 and both if I put a strong light from a flashlight in the top of the jaws(in the area where the jaws are milled thinner) i see the fine line of light passing through the jaws. I have same issues with 1 tesa caliper . With chinese calioer this issue not exist. Both Tesa and Mitutoyo are original 100% ( no fake ) bought to dealer . Are this Mitutoyo and Tesa caliper defective? or this make part of caliper tolerance?
to get a round any radius in on the edge of a part, say your measuring the depth of a counter bore, there will be a slight radius in the corner its to get around it
The cohesion of the 2 gauge blocks: the atoms of the 2 blocks of the same material are coming so close to each other at clean and very flat surfaces that they literally ' forget ' that they are in 2 distinct blocks. They form & line up & attract as if they are in the grid of 1 & the same block. Interestingly it happens very fast but not complete. Obviously this process is ongoing to ' result ' in a ' state ' that is know as ' cold weld '. This is a wonderful process. By the way: Gauge blocks are a Swedish invention ( Johansson 1901 )
I didn't know about the "step measurement" for calipers either until I read the manual 7 years ago. Even cheap harbor freight calipers show it. manuals.harborfreight.com/manuals/62000-62999/62569.pdf
In my “shop”...I watched a supervisor spill a bowl of stabilizer all over a bunch of gauge blocks. He didn’t clean it up at all. I washed them off after he left the cell. It’s sad when you see people mistreating the one thing that saves us from wasting time and money.
"Don't store gage blocks wrung together",and "don't store micrometers closed". Mic anvils should be as flat as gage blocks. So this is saying to not leave mic anvils wrung together. (And there is also differential expansion to consider that could increase the force in the mic and damage it on a temperature change.)
i loved my 0-1" quauntumike to death, was so quick to measure things not similar in width and with extreme accuracy! until one day it met the ground and snapped the piston in 2 pieces. I'll replace it one day but for now it's back to mechanical until i accumulate some other tools first.
Greg said you people aren't allowed to talk, then I said what happens when you say the words in your mind? People control, she's never read a book to be controlled, they try to make me dumb all the time, suppressed and controlled, burn all knowledge
great vid and a lot of use info. but can i ask one thing. bring the camera i a lotttt closer. eg when you were showing how to lock the 2 ceramic gauge blocks together having the camera a lot closer will let the viewer see exactly what your doing. as it was the camera was way back, we could see your whole person but the actual subject, ie the ceramic blocks where sort of hard to see well. anddddd.......just something of interest. you said never leave a measuring instrument closed when not being used. ie never leave a micrometer with the 2 faces locked together when not being used. well one time many years back i left a machinist vice closed shut over the weekend. we have a very cold snap that weekend. monday morning the moving jaw of the vice was cracked right through. so now if a ever see a vice closed shut i just have to unwind it a few turns. :)
So, for cheap calipers, leave them closed for the first year or two to break them in? My harbor freight have seem to have gotten better with use and careful storage (closed).
My metrology professor told us rule number 1: Don't trust the salespeople when buying equipment.
But these are all good tips.
Max Maker The difference is that Mitutoyo knows they're the best, with Starrett and B&S. They don't need to sell things, they just need to make sure you get what you need or at least things that might make your life easier. It'd be much different for a newcomer to try to convince you why their product is better and cheaper, without the reputation to fall back on.
The company sales people and many of the technicians know very little about the application or worse your application of their technology, but the big names have put in the most work figuring this out. Be prepared to pay for it. Mitutoyo and Brown and Sharp/Tesa are really in a class of their own.
Have you ever been a sales person? You may not understand that "we don't have to sell to you anymore" is the greatest marketing line ever created
Mitutoyo calipers can be considered among the best. Mitutoyo micrometers have a HUGE flaw by using flat standards. I wrote up a article on the errors from using a flat standard on a instrument that is made to check round parts. Im not nesc knocking Mitutoyo, just be aware that in critical work Starrett is king for mics. I do prefer Mitutoyo calipers over Starrett though :)
Jeremiah, you can always get round end standards if you are really worried about the accuracy in certain specific situation. And those mics? They are not "made to check round parts", they can be used for nearly anything.
I use Mitutoyo Micrometers and Calipers everyday. They are my personal tools and I make my living with them. Thank you, Mitutoyo, for making excellent tools.
Hey John,
Congratulations you are heading into the very interesting world of metrology. Your ability to make things is directly related to your ability to measure them. So your measuring has to be better than your manufacturing abilities.
On your gage blocks. There are wringing films on the gage block surfaces. These can contribute significantly to total gage block stack errors if not done correctly. In fact the published length of a gage block includes one wringing film as if it was wrung to a measuring platen.
"Metrology, Its a dirty business" (Oxtool quote)
Talk to you soon,
Tom
oxtoolco, I agree, but John missed thermal expansion. Robin Renz in one of his videos where he had setup your gauge block he restored, you can clearly see just from the heat of one finger move the indicator. I think it's something we should all be aware of like cosines and abbey errors. Quote: "Any measurement that you make without the knowledge of its uncertainty is completely meaningless."
Professor Walter Lewin, MIT
MrVajutza, I think this is more of a general introduction. If we were going to get picky we would address using a flat standard on a mic(big no no because of surface area/pressure) and also calibrating the mic to the position it will be used in because of gravity's effect(more critical on large mics), thermal expansion, etc. This is a great video to familiarize people with metrology. Good job John, and keep up the great work!
What's the name of Robin Renz channel? Thank you
Robrenz
The notch on the end of the caliper bar is to let you measure depth even when there is a slight radius at the bottom of a hole. Source: A friend of mine in R&D at Mitutoyo.
Can u let us know how to repair flange micrometer if flange wear?
On the topic of metrology and gravity, I once worked on a part for a hydro electric dam. It had a 24 foot inside diameter that needed to be measured with an inside micrometer. In order to compensate for the sag of the bar micrometer, it was calibrated on a laser setting device while being held only on each end of the bar. When measuring, the guy on each end had to hold the micrometer in the same spots the calibrating machine held it. Temperature differential between the part and measuring device also became a big factor.
Sweet Moses!
Welcome to the land surveyor's world, at least the world before lasers. You used a steel tape to measure distance. A 100' chain (tape) was good to a small fraction of an inch. IF it was level, and IF it was pulled to the right tension, and IF it was held correctly at the right points, and IF you measured the average temperature of the tape and applied the right compensation factor.
@@lwilton I'm not sure even my dad ever used a tape measure. He's been surveying for decades.
I always heard "measure twice, cut once". Which is great. But then a machinist colleague told me "cut twice and it's still too short"...that definitely changed the way I think about metrology.
John I just got up and went and opened ALL my thimbles and caliper jaws Thanks so much for the tips and all that you do for us out here in youtube class!
Thanks, would be great to hear from a carbide insert company about different grades and coatings.
Love this one, definently want to see more of this. I've heard people say "If you can measure it, you can machine it." I'm not sure if that's strictly true, but no doubt measuring is the cornerstone of getting it right.
Great vid. Even as a professional machinist I learned a few good points. It's funny that I've always stored my micrometers like that too, not because anyone told me, but just as a general observation of storing integrity dynamics. Glad to know I have not been overly paranoid all these years.
I thought I had a fair grasp on how to use all the items you guys showed. Man, SO MUCH I'd never considered! Great Vid guys. Thanks heaps!
I've got a 0-1" Quantumike and I later bought a 1-2" Quantumike. I love them both but find I don't need to use the 1-2" one nearly as often. To get consistent results you still need to develop a feel for the speed and force you use to close them even with the clutch. I also have a Mitutoyo 6" caliper that I carry around with me most of the day. I recently got one of Shars Aventor calipers for home and I'm really impressed with it for the price.
I am quite surprised that there was no mention of thermal expansion difference between steel and ceramic regarding the gage block demo (also carbide gage blocks). If your shop varies in temperature it is best to measure with as close of materials as possible (obviously no such thing as aluminum gage blocks of course) and the rate of expansion between ceramic and steel is different enough to cause issues should you be measuring at a temperature in which the part is not expected to operate. Dedicated inspection setups generally require a minimum of 24 hour temperature normalization in the same environment in which the gages are kept and then certified that they have been inspected at that temperature.
That is a biggie !!
Definitely want more of these!
John its Van der Waals force. The blocks once the air between them is removed stick because the materials contact so effectively. Same forces that drive capilary action and what sticks Gecos to walls. If two surfaces of pure metal (unoxidised) are placed against each other and they are PERFECTLY flat they will weld together. They will become one piece of metal. Most metal has at least a one molecule thick layer of oxide so this is very rare.
A friend of mine used to work in aerospace and he told me one of the challenges was that in the vacuum of space the high quality gold pins in multi-pin connectors will weld themselves together, therefore they need to be gas purged in order to prevent this from happening. I think it is known as cold-welding. Not sure if this is the same as Van der Waals force, but non the less an interesting challenge if you are building space-craft! Great video John. Thanks for this. I am surprised Mitutoyo do not have a video series on RUclips themselves. They are missing a trick there!
Wringing from the NIST Gage Block Handbook - www.mitutoyo.com/wp-content/uploads/2017/02/Wringing-from-NIST-Gage-Block-Handbook.pdf
Well.... mysterious-er and mysterious-r! So it seems the fact is nobody really knows......can you believe that!? We humans have a lot still to learn. (Me especially)
While that PDF sure has a great intro this one mentions the oil films with some extra details: www.starrett-webber.com/gb46.html i.e. "[Step] 2. Wipe the surfaces of the blocks to be wrung gently across the oiled Wring Pad. " and "Gage block length is defined as an interferometric measurement when the gage block is wrung to a
flat platen. This includes one wringing film in the defined length of the gage block"
It has little, if anything to do with Van der Waals forces, it’s merely atmospheric pressure pushing them together due to the fact that the air between the two smooth surfaces has been displaced. The only possible Van der Waals could be what is known as a London dispersion force which is a very weak type of temporary and spontaneous attraction common to all molecules.
John in my high performance engine machining class we learned to check parts by pinching the jaws of the caliper to the part instead of using the plastic or wheel. reasoning is you can't flex the caliper if you pinch at the contact point to your part.
Dear Mitutoyo, this was time well spent, you will now be my go-to metrology supplier.
Give John some new toys or something!
Very nice video John, keep them coming! Your shop is really looking good. Thanks for mentioning my channel it is greatly appreciated.
ATB, Robin
Hi John
About micrometers, the salesman from mitutoyo talk about the important
thing to remember. allways keep the surface clean. He only talk about calipers.
After few measurements with micrometers, and the contact surface is not clean.
Just use a copypaper, and turn it so it squeeze on the paper, and then pull the micrometer
away from the paper. Now you have a clean contact point
Only problem is that copy paper and most papers are abrasive and over time will scratch the faces.
Great video, such an important topic to us all, please MORE like this one!
I have a quantum micrometer. It's totally worth the extra. Makes taking measurements between different sized objects so much less of a chore.
look up codys lab on youtube. he is doing experiments with ringing parts together under a vacuum to eliminate the air being squeezed out theory.
Love that channel
which video
Julius Jahn it's one of his newest ones.
Smooth blocks will fuse together permanently due to so-called cold welding when they are wrung together in vacuum.
Liked this video! I learned several surprising things :)
Thanks for yet another excellent video!
Good stuff. This Old Tony did a video explaining cosine error recently. The sleeve trick is good, but be sure not to run it all the way down. Don Bailey over at Suburban Tool has a good video about micrometers.
Oh, this video will be helpful for a nubie like me!
steel gage blocks should be cleaned with block cleaner and stored with block preservative as for ringing, you are removing the air between the blocks which causes a sort of vacuum "
1. Air pressure from the surrounding environment as the air is squeezed out when the
blocks are slid together.
2. Surface tension from oil that remains on the gage blocks or water vapor from the air acts
as a glue to hold them together.
3. When two very flat surfaces are brought into such close contact with each other, this
allows an interchange of electrons between the atoms of the separate blocks, which
creates an attractive molecular force. (This force will remain even in a vacuum or if no oil
or water is present on the blocks.)
That clutching mechanism on some micrometers is for those who cannot measure by feel - sometimes measuring is an artform too. Also, gauge blocks are for those who don't trust their micrometers' or gauge. Let me know if that last sentence was grammatically correct.
Check out AvE's series on gauge blocks and cold welding
How long you been machining if you didnt know to look for light? You should check your tools often by measuring different sized gauge blocks
Well, this video was awesome.
Oh and you and Kemal get to explain to my wife what a quantum mic is and why we need 4 now. :)
Great video, learnt something, great tips as well. It would be good to see more.
Great tips here for hobby machinists!
In your metrology room, keep a stable temperature. don't hang onto the block for too long because they will expand (esp. small ones) beyond their nominal size. IIRC the correct temperature is 20°C but skin temperature in your hands is closer to 32°C.
I am not sure but I think the notch at the end of the depth bar is because a lot of parts have little radii between the face you want to measure and the wall the measuring tool is resting against, so that notch keeps the radius from interfering in the measurement. That's my theory at least.
Cheers
great video liked it a lot. But the ground top surfaces of a caliper john? Thats my most used meausuring technique. :)
Hi John. AVE did a good video understanding 'ringing' gauge blocks. Well it was good for beginners like me. Wonder if it would be cool to do a live Q&A session with Mitutoyo? Just a thought! Kindest regards. Joe.
I did learn something from this video, but not accounting for bracket sag is what happens when you get your CNC certification from RUclips
There's a great book you should read if you are into precision machining at all: "Foundations of Mechanical Accuracy" by Wayne R. Moore.
Out of print and currently selling for $5,000.00 used on Amazon.com!!! Take good care of your copy.
@@mesomachines you can order a copy from Moore between 60 and 100 dollars usd depending on how many copies they print
good job by both.
Wringing is caused by van der waals force. The molecules are attracted to each other, although normally not noticeable because the contact between two less flat surfaces is much less and it is a relatively weak force. With two precision surfaces there is enough contact for the force to be noticed. If the surfaces were flat enough, a covelant bond can be achieved and the 2 pieces would become one and not be removeable again.
The "gravity" trick at the end is... flawed. Your test indicator is picking up mostly compliance in your indicator stand. If you had it fixed with something more rigid and stronger than a magnetic force you would see considerably less.
The pattern maker of your parallel mentioned accommodating for gravity because of airy and Bessel points. They are essentially calculated points of where to support a beam to either have the ends parallel (airy) or top and bottom average the most parallel (bessel)
Cool stuff!
I was always told the wringing is helped by the lack of air pressure acting on the two flat surfaces since they are in contact so closely there is an absence of air between the mating surfaces. I also understand the sharing of Electrons is another theory....
How about testing the indicator theory of yours first before speaking out loud? Doesn't matter if you have a magnetic stand or not, the linkage & indicator will bend under gravity and is the reason why you shouldn't use them on a horizontal machine.
Hey John, You asked a question at 18:23, but did not answer...editing mistake or intentional?
I also agree with comments below ONE CAMERA would make it easier to watch.
I subscribed to their channel after I saw it on your Instagram. Not many views but good info. It's a shame they don't have more subscribers or views. It's great to see your shop in the background of their videos. Really great tips. Thanks.
Hey John I have a 0-1 quantumike and I use it all the time and hold tenths with it. Highly recommend.
I have the older quikmic. Good mic but really only for out of machine measuring. Is the quantumike good for in machine measurements?
dude, I need this. I'm just a electrician but I've been making a basement shop so yeah, definitely appreachiated
You dont need friction or ratchet features on a micrometer in order to measure accurately. It's all about developing a feel.
Martin Maurach
True. But the minor extra cost for it is so worth it, specially with tenths read outs.
The extra $10-$20 extra is a no brainer when you're dropping $150-$200 on a mic
I would rather not fiddle with a mic anymore than I have to. So I am all about the friction thimble! Plus, they are so dang cheap now, how could you not buy one?!
Every set that I've used winds up gummy and non consistent within no time.
User Name never had an issue with them. Had a pair for 6 years with no issue.
User Name I have never had an issue with three I own either. One being a cheap Fowler that I beat to hell and it still gives good results.
When verifying micrometer calibration I always do 0, 1/2, and full open Using gage blocks or standards. If you don't do that you can't trust the micrometer as some mics will have variance in the readings do to inaccurate or damaged threads and this will not show up by merely zeroing out. Indicators like the Interapid and Last word are intended to be comparitive reading tools and not actually measuring devices. As such there is no need to worry about cosine error with them as the measurements are always comparitive and not actual.
A better method is to create a few random gage block stack sizes so you aren't always on the same revolution of the thimble and thread contact.
Steinwerks select them such that you get 0,90,180,270 around the barrel. iirc mit makes a small set that includes an optical flat for this.
Why stop with only 4 positions?
Because it is all you really need, and measurements take time. You could probably get away with 3 positions. The major error that you are looking for by checking different angles is not thread error, but the faces not being exactly parallel to each other and perpendicular to the screw axis.
I would never suggest using a gage block to calibrate a OD Mic. Do this little experiment and you will see why...calibrate your mic with a radiused standard or calibrated gage pin. Next get a calibrated gage block and measure it. the Micrometer on average will mic a flat surface .0002 larger. Starrett says on average its .0001 but I have found it to be closer to .0002. This can be huge in real job shops where every job is different. In our area (houston) many of us work with extremely tight tolerances and can not afford to have deviations at times that large. hope this helps!
Great tools. Our shop is loaded with them
Love the information and videos. Always learn something, even after 20 plus years of machining.
Wish this video showed a more close up and detailed view of the measuring techniques you use.
Thank you, and I appreciate your time and effort explaining difficulties and solutions to what seem like easy answers.
I'll stay tuned for more knowledge and help you provide.
Thanks again ,
Michael
How does the Mitutoyo LH-600 compare to a traditional CMM or a used Faro arm? The costs of a CMM are higher, but the linear height gauge looks a bit limited in comparison. For practical matters, does the linear height gauge get one most of the way to what a CMM can do? Thank you
Hi John, next time you talk to Mitutoyo ask them why they don't make a digital caliper with the display facing the top so you can read it while measuring parts in the lathe. It would sure beat having to stick your head in the lathe to see the display!
Most everyone I've seen do manufacture what are usually called "left handed calipers". Makes it easy to see, but I ditched them after a week as my hands and brain just didn't want to learn a differently working tool.
maybe its because nobody uses calipers on a lathe because theyre too inaccurate
Use a mirror prism
You can read about gauge blocks here: www.nist.gov/sites/default/files/documents/calibrations/mono180.pdf
John, This was an awesome video. Special thanks to you and Mitutoyo for sharing all the info. There is so much to learn about metrology but so little information like this out there. Keep it coming.
Great stuff, thanks
Great info enjoy the class
Was it gravity or magnetism when you turned your parallel upside down ?? there is something to think about !!! LOL
I'd like to see Mitutoyo demonstrate their 050001 Caliper centre attachment. I've got a pair for accurately measuring screw hole centres, but just don't trust them.
5:05 Yep, That "Damnit moment".. when you think you have it. :-)
Awesome vid. I used mics when I was a noob machinist in the 90's and I use calipers all the time at work for modeling things but this video was a nice reminder of the correct way to have repeat-ability. LOL, why do I love this stuff so much? Damn right I want to see more.
for some reasons i cant watch it more than 30sec at the time. There's so many abrupt camera transitions it gets me dizzy
im not even high !
same here, this only needed 2 cameras
The gravity demo is perfectly logical and startling just the same.
So how do you properly indicate a drill with gravity working against you?
Answer this already someone!
2 years later and this video is still great! Thanks John and Mitutoyo!
Great video! :-) May I please ask what you do to take shrinkage and expansion into account when temperature changes?
If you have ceramic blocks but are measuring steel in the summer at 118 deg F and later in the winter at 78 deg F?
Thank you John, this is some of the best stuff I've seen for a long time. Many tips and tricks for us new guys to machining and measuring. Excellent. One thing you did not mention with respect to the pressure on calipers; one should practice and develop the feel for correct pressure by repeat measuring gauge block and gauge pins. Stefan Gotteswinter has demonstrated the gravity effect in one of his excellent videos. His is the only mention of this I've seen before.
Boy that Mitutoyo guy was nervous when you flapped that stack of gauge blocks around, he was following your every move. LOL
Keep up the good work
@NYCCNC The answer to 18:21: On my old Mitutoyo dial calipers it's obvious - the bar has a "b" profile, with a square bar running down the channel and a thin tang to cover the rack gear next to the channel and keep the shop goo out. The thin tang is cut off about .23" from the end, leaving just the square bar. Digital calipers don't use a rack gear, so the bar can just be a rectangle for stiffness, but they cut the end down to fit in smaller spaces - and just kept the offset style of the manual calipers for aesthetics (and also probably the simplest to machine).
Why don't those reference pins have a rounded end with the diameter of the overall length so you don't have to have it perfectly aligned
I think, because tthe round surface 'point' has, essentially, infinite force at an infinitely-small contact', it will always be subject to an indefinable compression, thus having a length that varies with pressure of the measuring device; this effect is also observed in kinematic mounting systems, which demand very hard 'balls' for location points.
Who knew? The plural of stylus is styli. :-)
Very cool and informative video, John.
It's from Latin. Anything that ends in 'us' has a plural ending in 'i' - for example Radius / Radii - fungus / fungi. Unfortunately not all words ending in "us" are Latin, and therefore as a rule it is not terribly useful. But your-man from Mitutoyo is correct. It's styli :-)
Toyotas are nice but those Lexi...
What is Mitutoyo doing to stop the fake Mitutoyo manufacturers? I buy used tools mostly, but Mitutoyo is one that I won't buy because there are so many fakes out there that I don't want to pay $100 or $200 for one and find out that it's a fake.
Gage block adhesion after the air has been pushed out of the way,is due to the electron's around every surface atom switching place's with the atom next to it .this is called the Van der Waal's force, they don't have to be the same material's to do this they just need to be very flat .the closer they are the more electron's may jump from one atom to the next . hope that helped John.
John, no need to feel bad about not understanding the physics behind wringing gauge blocks... I've done a lot of research on wringing and as far as I can tell, nobody has proven how it works!
It's definitely not "wringing the air out" and atmospheric pressure pushing them together, I've seen blocks wrung together, then put in a vacuum chamber and they still hold with the same force as they do under atmospheric pressure...
My guess is Van der Waals forces - They're so flat that they end up working like gecko feet on a macro-scale...
Whatever the explanation, it's one of those that I hope is figured out within my lifetime! lol
ringing is exploiting van der waals forces that cannot come into play without the linear alignment of a rougher surface
Loved the gravity demo. I blew an entire Saturday chasing a few thou lost to gravity. Your *click* moment was way more exciting than mine!
I bet people often ask them what the weather will be like. haha
You can interface a mitutoyo to an Arduino or Raspberry Pi - www.instructables.com/id/Interfacing-a-Digital-Micrometer-to-a-Microcontrol/
Just wanted to add: the rabbit hole goes a whole lot deeper.
Mitutoyo needs to measure their own measuring tools. So they have their own primary reference. Which in itself is probably referenced at your national metrology institute at their secondary reference. They intern will use a primary reference (our primary weight reference doesn't leave its vacuum chamber but twice a year).
The national primary reference will be sent to Paris, France ever so often.
So see if you can visit your national metrology institute. www.nist.gov/iaao/national-metrology-laboratories
That would not be necessary since they redefined the kilogram to be based on the Planck constant instead of a physical kilogram standard.
John, When you do an advanced video, can you include the error caused by holding a micrometer in your hand too long? When I looked it up, I stopped resting my mike on the manual lathe because of thermal expansion.
Measure Me: I bought a _Kennedy_ 9.00mm (0.3543in) gauge block, measured with three different mics, it only deviated by -2µ. My _Kennedy_ 3.50mm (0.1377in) gauge block only deviated by -1µ which is meggafabtastic💨accurate. I used a Mitutoyo, Moore & Wright and Linear mic all calibrated at 20C degrees to be B💥NG on.
Instrument le Grande: My Mitutoyo mic is superior quality and accuracy, reading down to 0.001mm (1 micron) which is pretty C⭕⭕L for a mechanical mic. The Japanese have sure got engineering down to a fine art. If it says "Made In Japan" on it, you _know_ its going to be great!...Now I'm off to peruse Japanese gauges on eBay...excuse me...👀
I may need to get one of those height gages(gauges?) to check my cars ride height
Great video John. That setup to show how gravity affects and pulls on the holder was awesome. Very informative video. Hope to see more like this
Cody's Lab covered this exact question about what makes the guage blocks stick.
ruclips.net/video/jNEvS_bjKIo/видео.html
I thought it was the vacuum created by pushing out the air. Cody showed the truth of that hypothesis.
He's got a cool channel has done things like measure that pressure or force light generates.
My Teacher (Boss), when I was learning my Tool and Die maker trade, (way before I became an Engineer), set my mind in motion regarding precision, and measurement, and would scream at me for using a caliper for anything less than +/- 0.010" (Use a micrometer, he's scream, and 40 years later, it is still valid.
The best way to challenge a measurement systems rep is to run a type 1 MSA (consistency test) on a measurand you supply. Have them take 30 repeat readings, then generate XmR charts with Probable Error (PE) and Cg, Cgk output test indices. Also determine the Bias of your checking against a known standard.
13:47
its called Cohesion........the surface is so flat, that the atoms come so near together, that they stick.........nothing with vacuum or dump xD ...........
see: en.wikipedia.org/wiki/Cohesion_(chemistry)
if u leave steel gages connectet for a week, they probably will be cold welded by diffusion....
I own 2 mitutoyo calipef 500-752-20 and both if I put a strong light from a flashlight in the top of the jaws(in the area where the jaws are milled thinner) i see the fine line of light passing through the jaws.
I have same issues with 1 tesa caliper .
With chinese calioer this issue not exist.
Both Tesa and Mitutoyo are original 100% ( no fake ) bought to dealer .
Are this Mitutoyo and Tesa caliper defective? or this make part of caliper tolerance?
18:21 So what *is* the answer to this question?
to get a round any radius in on the edge of a part, say your measuring the depth of a counter bore, there will be a slight radius in the corner its to get around it
The cohesion of the 2 gauge blocks: the atoms of the 2 blocks of the same material are coming so close to each other at clean and very flat surfaces that they literally ' forget ' that they are in 2 distinct blocks. They form & line up & attract as if they are in the grid of 1 & the same block. Interestingly it happens very fast but not complete. Obviously this process is ongoing to ' result ' in a ' state ' that is know as ' cold weld '. This is a wonderful process.
By the way: Gauge blocks are a Swedish invention ( Johansson 1901 )
I didn't know about the "step measurement" for calipers either until I read the manual 7 years ago. Even cheap harbor freight calipers show it. manuals.harborfreight.com/manuals/62000-62999/62569.pdf
In my “shop”...I watched a supervisor spill a bowl of stabilizer all over a bunch of gauge blocks. He didn’t clean it up at all. I washed them off after he left the cell. It’s sad when you see people mistreating the one thing that saves us from wasting time and money.
"Don't store gage blocks wrung together",and "don't store micrometers closed". Mic anvils should be as flat as gage blocks. So this is saying to not leave mic anvils wrung together. (And there is also differential expansion to consider that could increase the force in the mic and damage it on a temperature change.)
i loved my 0-1" quauntumike to death, was so quick to measure things not similar in width and with extreme accuracy! until one day it met the ground and snapped the piston in 2 pieces. I'll replace it one day but for now it's back to mechanical until i accumulate some other tools first.
depth bar is notched for smaller holes and slots, without losing strength of the otherwise full width.
Did anyone else wonder why he would be talking about weather?
I hope mitutoyo left you a quantumike and ceramic gauge block set for doing this vid👍👌🇦🇺
Great video. Al though it’s density not gravity causing the indicator’s movement while rotating upside down.
Greg said you people aren't allowed to talk, then I said what happens when you say the words in your mind? People control, she's never read a book to be controlled, they try to make me dumb all the time, suppressed and controlled, burn all knowledge
wonderful and informative, definitly would like to see more
Cheers
I would also recommend toms techniques youtube on setting up a gauge block stack ruclips.net/video/BGRU2fyQ7Uw/видео.html
Why film this , IF you don't show a close-up of what your describing, it is really meaningless
great vid and a lot of use info. but can i ask one thing. bring the camera i a lotttt closer. eg when you were showing how to lock the 2 ceramic gauge blocks together having the camera a lot closer will let the viewer see exactly what your doing. as it was the camera was way back, we could see your whole person but the actual subject, ie the ceramic blocks where sort of hard to see well.
anddddd.......just something of interest. you said never leave a measuring instrument closed when not being used. ie never leave a micrometer with the 2 faces locked together when not being used. well one time many years back i left a machinist vice closed shut over the weekend. we have a very cold snap that weekend. monday morning the moving jaw of the vice was cracked right through. so now if a ever see a vice closed shut i just have to unwind it a few turns. :)
So, for cheap calipers, leave them closed for the first year or two to break them in? My harbor freight have seem to have gotten better with use and careful storage (closed).