Something I was taught was to hold the caliper across the spring. Apparently the strength needed to hold the caliper still is enough to throw the jaws out slightly if you grasp the tool in line with the spring. I was also told to stop the lathe, not for safety but because a less than perfect finish can abrade the tips of the jaws leaving you large.
those suggestions are very inciteful. Also, stopping the machine would give one a more accurate feel it would seem. As running would obscure the static friction feel I would think.
This was very beneficial Mr. Pete! As you are aware from my history, my grandfather used calipers to teach me how to do basic machining in the 1960s. He could hit the number on the first try almost every time. I still have all his calipers. However.... because of TH-cam and the top-notch creators (yourself at the top) there has been a revolution toward digital micrometers, calipers, DROs and so forth in an attempt to strive for ten-thousands accuracy. In my humble opinion, one must FIRST learn how to use ALL the measuring equipment! And the "feel" of ALL measuring devices is extremely important and must be LEARNED by trial and error. It doesn't matter WHAT type of instrument one uses (digital or analog). If you don't accurately set it against the reference AND the part, one will NEVER get the "correct" reading. Thanks for hammering the "feel" and please hammer again! Maybe after were dead and buried a machine with AI will be hooked to an iPhone and all the "machinist" will have to do is tell it "turn this part to 1.398160" diameter!"
I would say the use of all the micrometers, digital calipers and dro is in a high part about speed of completion of the job. I have used calipers many times but it is in some part a bit of educated guessing. It all matters also to the tolerance level you need to achieve. I to believe you should learn and be familiar with all the measurement techniques, even calipers.
Yeepers, Lyle took me back 55+ yrs this morning as well. Grandad was a master cabinet maker, and still have his old 1944 Delta lathe and all the calipers ( most LS Starrett) he used up to 1970. Now 70, and every time I pick up one of his tools, get to flash back to those by gone years. Bear. Hobbyist Machinist in TX.
@@mrpete222 Can you have another go at this but with an INSIDE caliper on a bore? Most people have to use inside telescopic gauges combined with a micrometer. I wonder if an inside caliper might be able to do the same job and possibly better.
I’ve been building a PM Research shaper. During the build I found it easier to use both internal and external calipers because of space issues. I was amazed how accurate they were if I took my time. I didn’t think to use gauge blocks, but will from now on. Thanks for information.
Hello Mr Pete, I been a long time fan. Just this year I finally just got myself a new lathe, and milling machine. Last time I did any matching was decades ago. Your channel helped me to sparked my interest in machining again. Keep up the good work.
Up until the 1940s, every machinist in America had two tools that they owned themselves: a 4" outside caliper and a 6" machinists scale. You carried both in your lapel pocket on your shirt or overalls. Most drawings in those days used fractional measurements rather than decimal, with 1/64th inch being about the finest graduation of a measurement. You pulled out the calipers and scale, hooked one end of the caliper on the end of the scale, then twiddled the knob until the other point was right on the measurement you wanted. Measurement was as Mr. Pete did, and it was good enough for almost everything, including bearing fits (which were babbit in those days, not roller bearings). By the 1940s decimal measurements were becoming common, and you could get machinists scales with 1/64 and 1/100 calibrated scales on the same scale. The other side usually had 1/16 and 1/10 scales, which are much easier to read, and could be used for setting rough cuts.
Thanks Mr. Pete. This is what Mr. Weber, my ACHS metal shop teacher showed us 40 years ago. I appreciate the videos and the opportunity to keep learning.
I also have watched many of those overseas machine shops. Always amazed how much they do with ancient machines and calipers. I guess if you do it for years you must get good at it!! Great video Mr.Pete. Thanks for your efforts!
I like inside calipers for precision fits in small bores which my verniers won't fit in (below 10mm). Haven't tried using outside calipers for precision fits yet, but I like using them to quickly scan through a pile of stock to find one suitable for the job I want to do. Set the caliper for the diameter needed and just slip them over the bar stocks - if it fits, it's too small, if it doesn't you've got yourself a winner.
Back in the 60s a fellow from a railroad repair shop came to work in our shop and he said that almost all of their repair work was done using calipers.
My highschool shop teacher taught us this way back in the early seventies. Getting the feel consistently was hard for some kids. Make the cut and blue the piece. If you scratch off the blueing cut more. Barely making a mark and you were right on.
I’m sure you and I are not the only ones that had the question of the accuracy while using the calipers in those videos from overseas. Great video Mr. Pete!
I really enjoyed this. Got a couple Kennedy drawers full with these,( mostly because if I see them I buy them…. Yup it’s a sickness)Thanks for the video Mr Pete.
Worked as a sparky in large maintenance shops and inherited a few calibers . Noticed that the younger guys never used calibers while say turning something in one of our 5 lathes. Guys who called themselves machnists in our shop that never worked a minute in a machine or tool & die shop never had halve of the tools a real deal machnists had. At least two of these guys never owned a micrometer.Thank you Mr Pete for all of the interesting & informative vidios.
I will often use a spring caliper on my engine lathe to rough down to about .010 from final, then switch to the micrometer & sneak up on the desired. This likely from many years of wood turning spring set large to over size for quick rough down, then re set & carefully down to final.
Mr Pete, when I was an apprentice machinist early 70s, in Australia, we were trained to use calipers for all bore work. Spring calipers were not allowed, they had to be fixed jaw type. Apparently spring caliper are not as accurate as fixed.The feel that was required was " feel until you don't feel", that same feel had to be used in the outside micrometer for measurement. Very accurate work was done. All the machinists used them. Didn't see telescopics till I started a toolmakers course.
A suggestion to help with the learning curve, machine a piece of stock to ''x'' via micrometer then set caliper via gauge block having same dimension of stock ''x'' , then familiarize yourself with the amount of drag present when checking the dimension. Practice Makes Perfect. :)
What you never see in those videos from third world countries machining under crude conditions is how well the repaired parts fit when re-installed. And how long they last compared to OEM parts. You do have to give credit though when someone has developed that “feel” for the work they perform. It is an art.
I second this. Being on the receiving end of such parts I found they work satisfactory, to get you out in a pinch until the real part arrives. Sometimes you need a one-time tool (e.g. special bearing/bushing puller) that the original expensive part does not justify the price. Also, a lot of them are not really trained in machining, they just did some apprentice time and their expertise is in welding or painting. I have a lot of respect for those self-taught people. Most of them do not have the money/tools to make a truly finished part or work with hard metals.
Spring calipers are great for initial roughing since you don't have to stop the machine to measure. Inside spring calipers are also capable of measuring internal grooves that microwave and slide calipers can't reach. I'm currently making some soft hammer faces with an internal thread, and spring calipers are the easiest way of measuring the thread relief to ensure it's deep enough. You just get a nice feel, squeeze the legs a bit to get them out of the bore, and then let them snap back to measure them.
I use my spring calipers to rough in o ring grooves on my lathe while it's running. Saves having to constantly stop and check with dial calipers or groove micrometers. It's all about feel. I don't trust it for the one thou tolerance, but it gets me to that last 10 or 20. Thanks for sharing!
I use mine to rough in new parts .010 over size and let part cool, then finish machining. Learned that from an old crusty machinist born the year my 9 inch SB lathe was built.
I've read several places that some of the aforable hobby lathes available in England after the war didn't come with graduated dials. Yet many fine projects were done on them. I suspect a lot of the work was done using spring calipers, but without the benefit of a gauge block. Practice. I love my diamond/tangential tool holders. It's my "opinion" that most hobbyists would be much better off with high speed steel and tangential tool holder then investing in carbide. Especially for the vintage Southbends, Logan's, etc. It's just too easy to sharpen them and keep sharp with honing, rarely a need to regrind. Gary of Eccentric Engineering is a great guy, Hope to hear more about your experience with them.
I recall my father using an inside spring caliper to bore a recess for a press fit bearing. He had outside mics which he used to size and hold the diameter of the bearing bush. But then would pick up the bore size with the inside caliper and measure it with the micrometer. Much like a telescoping gauge being checked. And yes, the bearing was a nice firm but "in scale" final fit. Much like you I had a fun shop evening a few years back doing more or less what you did. I did some outside stuff and some inside stuff. It very much is a sense of feel and skill that takes some practice. But it didn't take long before I was hitting my sizes within .001 or less... at least most of the time....
I've seen those Pakistani or Indian machining videos. They have huge machines! Saw one where had some kind of spring steel thing on a base that they used to indicate in a 4-jaw chuck! Interesting stuff for sure
I have always wanted to see a real demo on these types of calipers. I have a set of I/D and a set of Morphydite. The inside ones are great when there is a shaft inside the hole you are measuring. I use the roll in method similar to using snap gages. They are also friction joint and not screw type. I will be looking for a set of the friction type for O/D measuring. Just for fun. I like using the old ways. The Old timers did the walking so We can Run. It is that simple. Now we have machines that do their own calibration and measuring. What fun is that! Thanks as always Mr. Pete for bringing us along and making it interesting.
It is nice to hear you say about the skilled machinists from India and Pakistan. There are loads of nasty comments about them but tbh I can't fault their skills working with what they have. I bet most of the comments are from people who have never used a lathe! Great video!
Well, now I will have to pull out grandpa's vintage calipers (showed back in 2019 during my quarantine quickies) and do some test runs as well. I do use his in side calipers quite often for rough in's, but of course relay on my good old Starrett's mic's and adjustable gauges for end results. Thx Lyle for doing this Short, took me back 55+ yrs this morning 🤔👍
Mr. Pete, I also watch the Pakistani Truck channel and many similar ones. It's really an exceptional experience just to follow them and I often wonder what you and the other TH-cam machining mainstays would say. Thanks for this contribution. They also use the calipers while the machines are running, even on those enormous lathes, to measure parts 20 in. in diameter and more. I sometimes worry about them but they all still have 2 arms. I imagine a caliper can spread and set a tiny bit with all those tight measurements, and also the friction from running measurements may shave the tips, hence the actual workpiece size may be a hair different (larger I suppose) than measured. I guess they recalibrate every few hours.
Well, they don't put the ones who lost something in the vids is all. They make ol' Lefty One Eye take the day off when the cameras are rolling. They probably get the guys who lost stuff on the right side team up with guys who lost stuff on the left. Also remember, life is pretty cheap over there. The REAL amazing part of those vids is those skilled machinists over there only get about a dollar a day, a hand full of rice and all the water they can drink from a garden hose as pay.
Thank you for showing this, and I am glad you have found a new to you method. I have entirely too many internal and external calipers (bowspring, firm joint, and others). They get a fair bit of use. Most useful for matching dimensions, such as repetitive work and duplication, but also quite useful for comparative work. Inside are also nice for centering when there is large clearance (2 inch piston rod in an 18 inch bore, for example). I rarely use them to hit a particular dimension if I can use any other measuring tool, but fairly often use them during roughing, set maybe one cut depth off final size for easy progress checks when removing a lot of material.
Great video. My shop teacher told us not to "waste shop time" using micrometers and such if calipers, rulers and machine dials were adequate for the job in hand. We were not even allowed to use precision measures for our first couple of projects (hammer, drill sharpening gauge). He had similar thoughts about using files and other hand tools before "wasting shop time" setting up a machine.
I have a drawer in one of my tool boxes dedicated to spring calipers, but the only time they ever get used is for measuring hard to access dimensions where nothing else will fit. The one that gets the most use is a 14.5" Starrett that has no model number, but does have a 1901 patent date. Thanks for the video!
I use spring calipers all the time for bore work since I can clear the tool in the bore. getting the right "feel" to hit within .001" is pretty easy, getting to .0005" +- is a lot harder.
I was shown a trick by an old tradesman back in the sixties, when I was an apprentice. It works well with telescopic gauges as well. I am not as dexterous as I used to be but I can still achieve an accuracy of 0.003mm. Hold the micrometre in your left hand so you are looking at the back of the barrel, the thimble is adjusted by one finger on that hand. The inside spring caliper is in your right hand same as when it was in the bore. Concentrate on the feel as when you were in the bore. Since you cannot read the micrometre you are not distracted by what it is reading. Back in the day I was just as good with firm joint calipers.
It's all about "feel". It doesn't matter what measuring device you are using, OD mic. ID mic, Caliper, etc. I never let my trainees use the "clicker" on an OD mic to force them to develop the feel. I also required them to read the device while it was in contact with the work, if at all possible, as the device could move while being removed from the work.
Mr. Pete, you are the best. I've seen these calipers and never used them. I watched right with you with an open mind and am now a believer these simple calipers have a place maybe to get you close +/- 0.010. What I hate is the risk of killing a shaft; the .947 is the worst feeling. You would need to keep gauge blocks handy I guess to use them; I love my dial calipers. Those guys in Pakistan welding and turning a broken dump truck crank in the dirt! UNBELIEVABLE!!!!!!!!!!!
You must watch the Pakastani truck channel too Mr Pete! Great Video I often portable line bore construction machinery using spring calipers for checking where I am at during the process. With some practice you can machine surprisingly accurate with a set of calipers and a Vernier or dial caliper for a reference. Analog measurement is not dead yet!
Great video; I had also been sharing the same doubt, especially after seeing those gentlemen truing up the stock in the chuck by using, instead of a dial test gauge, a piece of steel wire with a sharp tip :). Thanks, Mr Pete.
Not surprised at all. Ancient stone masons used to achieve very precise levels of accuracy using the most rudimentary hand tools and measurement methods. Traditionally the greatest precision was achieved with hand finishing techniques, albeit with a lot of knowledge, skill and practice.
I used to use spring calipers for aligning motor couplings regularly. I learned to use both methods in trade school and find using calipers rather than a dial gauge much faster.
Hi Mr Pete i also watch some of there videos and can't believe how they can make things like crankshafts from start to finish . no safety gear maybe not even a good pair of shoes . I don't think there quality standards would of been excepted in the USA but i could be wrong . I like seeing the gang of workers on the end of a huge pair of tongs with a red hot huck of iron in a huge hydronic hammer machine . Thanks for the videos . JM
When I first set up a lathe at home, I had no snap gages, so calipers were the rule for inside bores. I had no problems getting within .003" using them, finer than that required a bit more finesse. Before the introduction of micrometers in the 1890's, most turning was done using calipers, usually set off of a ruler. The fellow using the lathe or planer knew the pitch of the leadscrew on the cross slide, so if it was 8 threads per inch, one turn was 1/8", one half turn was 1/16" and so on. Thousandths were not even considered. Press fits were done off the mating part. mrpete has shown how it was done back before the 1890's, it's an interesting exercise to try if you have a lathe, and if you have an older lathe without graduated dials, knowing what was shown here can make it a useful tool even in a modern home shop. Great video!
I have always been curious about the caliper method employed by the folks in that part of the world and enjoyed your demonstration. Those folks over there are, in my opinion, some pretty skilled craftsmen to do the work they do with what looks like pretty well used and dated machinery yet they are doing some pretty precise work with those calipers, it would appear. Thanks again, that was a fun video!
Good experiment. I use calipers with my wood turning, as you mentioned you have done, and it works well for the projects I have finished. But I get the need for much tighter tolerances in machining metal.
Thanks for sharing that example. I watch a lot of those videos, and I have to admit, that I kind of chuckled at the techniques that they use. But it didn't take long to realize that they were accomplishing the job, with some very fundamental tools and techniques. Like they say in racing "Run what ya brung" :)
I have used the method multiple times. I especially used it with inside micrometers, where my telescoping gauge would not reach as far down in. The customer needed the bore opened up down into the bore..
I duplicated a part for a router using a crescent wrench, comparing fit & feel between the original part and the new one. That was back in 81 or 82, when Mr. Bob allowed me to add some experience to my book learning about machining. Didn't have a mic available at the time.
@@mrpete222 now that i think of it, I've used big adjustable wrenches to measure driveline tubes and pipes. Also framing sqares, stacked on each other, for even larger diameter's, when fractional measurements were good enough. Like for the initial set up of drum brakes ...
I have a few sets of inside calipers, not sure the brand, they seem to be fairly old. Used em a few times and was happy with the results. I gave a large size outside caliper made by LS Starret. Not sure how these are sized. Overall length is 24 3/8” and across the two legs while closed the measure 15 1/8” outside to outside. Haven’t see them to machine anything because they are so large. Don’t do much work that bug. Thanks for the video Mr. Pete.
The idea behind any precision turning is consistency. You hand 10 machinists spring calipers set to the same gage block, and you'll get 10 different dimensions. Also the type and quantity of the calipers will make a difference. First consideration is tolerance second is consistency. I've used this method on wood and metal patterns, but the tolerance was +/-.015". so not a big deal. Fit is the next consideration, is it a press, slip or it doesn't matter fit.
Very interesting. Thanks. I have watched some of those videos from Oakistan, possibly India. They do masterful work along with teamwork to get a job done. Unions would say they work too fast and they need more people. Ah, what would we do without unions today?
Having worked in that part of the world, we also ran machinery with a very minimal amount of oil. The arid conditions mean that any surface wet with oil turns to grinding compound.
GREAT VIDEO! Like you, I have watched those Pakistani machinists and mechanics and marveled at the work they do with primitive tools, conditions and machines. There is always a long list of comments from the "Safety Sallys" who can't get beyond they aren't wearing steel toed boots, but if the truth were known, those guys never do anything other than watch TH-cam videos. I do much of my work using calipers and have found things work best if you stick with the same pair of calipers and don't change the way the work is held in the machine. This was a very interesting video. Thanks for producing it! With a little care and common sense, there is nothing unsafe about using a caliper "on the fly" as my old shop teacher used to call it.
Steady hands are extremely important for Brain Surgeons and Machinists : ) A good set of calipers weren't inexpensive and are precision instruments. This is another time when Prussian blue is used for precision work...the length of the amount of drag (the chord length) is measured with a scale and trigged to determine how much larger or smaller in diameter that the machined part is relative to the round part that the caliper was set to; which was also done with the thinnest smear of Prussian Blue on the contact points of the caliper. Prussian Blue used to be very important for all machinists just a few decades ago. This method might be found in the "Machinist's Handbook" but I doubt it. I learned this one from my tool and die mentor.
I can see this as a possibility, but calipers will "spring" to some degree when passing over the work. A machinist would need to have experience as to the friction they should feel to be accurate. I can see this being eventually acquired. Thanks.
OK Mr Pete ... the outside calipers work, but I just don't know about taking a measurement while the machine is running, especially with those somewhat unpredictable strings of aluminum coming off. I've had this set of 10 fingers for going on 73 years and I am quite fond of them. Also, at my age I'm just not so much in a hurry I can't turn off the machine to make a measure. I might be able to walk with a wooden leg, but I'm pretty sure I can't play the guitar with wooden fingers.
Instresting test, I think if you had a round test pin, to set your calipers on, so your feel, is comparing round with round would be more accurate. Also would your feel get better the more you practice?
what they don't show you in those shops "over seas" is the finished job actually working like new in the machine they took it out of... I saw one where they welded back together a large diesel crankshaft that had split in half... I wouldnt trust that crank past idle for more than a week... granted im sure the tolerances were so bad that assembly grease was required instead of oil
I've been really wondering about the calipers in those videos, great video idea! I'd always stopped the machine because I was thinking of the wear on the tips. I suppose measuring while running you could get caught in the chips and that might be exciting.
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Something I was taught was to hold the caliper across the spring. Apparently the strength needed to hold the caliper still is enough to throw the jaws out slightly if you grasp the tool in line with the spring. I was also told to stop the lathe, not for safety but because a less than perfect finish can abrade the tips of the jaws leaving you large.
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those suggestions are very inciteful. Also, stopping the machine would give one a more accurate feel it would seem. As running would obscure the static friction feel I would think.
This was very beneficial Mr. Pete! As you are aware from my history, my grandfather used calipers to teach me how to do basic machining in the 1960s. He could hit the number on the first try almost every time. I still have all his calipers. However.... because of TH-cam and the top-notch creators (yourself at the top) there has been a revolution toward digital micrometers, calipers, DROs and so forth in an attempt to strive for ten-thousands accuracy. In my humble opinion, one must FIRST learn how to use ALL the measuring equipment! And the "feel" of ALL measuring devices is extremely important and must be LEARNED by trial and error. It doesn't matter WHAT type of instrument one uses (digital or analog). If you don't accurately set it against the reference AND the part, one will NEVER get the "correct" reading. Thanks for hammering the "feel" and please hammer again! Maybe after were dead and buried a machine with AI will be hooked to an iPhone and all the "machinist" will have to do is tell it "turn this part to 1.398160" diameter!"
Great comment JAy
I would say the use of all the micrometers, digital calipers and dro is in a high part about speed of completion of the job. I have used calipers many times but it is in some part a bit of educated guessing. It all matters also to the tolerance level you need to achieve. I to believe you should learn and be familiar with all the measurement techniques, even calipers.
well said Jay, cheers from Florida, Paul
Yeepers, Lyle took me back 55+ yrs this morning as well. Grandad was a master cabinet maker, and still have his old 1944 Delta lathe and all the calipers ( most LS Starrett) he used up to 1970. Now 70, and every time I pick up one of his tools, get to flash back to those by gone years. Bear. Hobbyist Machinist in TX.
@@mrpete222 Can you have another go at this but with an INSIDE caliper on a bore?
Most people have to use inside telescopic gauges combined with a micrometer.
I wonder if an inside caliper might be able to do the same job and possibly better.
Having a cheap pair that you can grind down thin for measuring snap ring grooves is really handy.
I’ve been building a PM Research shaper. During the build I found it easier to use both internal and external calipers because of space issues. I was amazed how accurate they were if I took my time. I didn’t think to use gauge blocks, but will from now on. Thanks for information.
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Hello Mr Pete, I been a long time fan. Just this year I finally just got myself a new lathe, and milling machine. Last time I did any matching was decades ago. Your channel helped me to sparked my interest in machining again. Keep up the good work.
That is awesome!
Up until the 1940s, every machinist in America had two tools that they owned themselves: a 4" outside caliper and a 6" machinists scale. You carried both in your lapel pocket on your shirt or overalls. Most drawings in those days used fractional measurements rather than decimal, with 1/64th inch being about the finest graduation of a measurement.
You pulled out the calipers and scale, hooked one end of the caliper on the end of the scale, then twiddled the knob until the other point was right on the measurement you wanted. Measurement was as Mr. Pete did, and it was good enough for almost everything, including bearing fits (which were babbit in those days, not roller bearings).
By the 1940s decimal measurements were becoming common, and you could get machinists scales with 1/64 and 1/100 calibrated scales on the same scale. The other side usually had 1/16 and 1/10 scales, which are much easier to read, and could be used for setting rough cuts.
Thanks
I just bought 3 beautiful Starrett calipers for $20 and can't wait to receive them. They are a thing of beauty
My Dad who started his apprenticeship around 1940 spoke of "old timers" using this method. I am gong to give it a try too.
Thanks Mr. Pete. This is what Mr. Weber, my ACHS metal shop teacher showed us 40 years ago. I appreciate the videos and the opportunity to keep learning.
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I also have watched many of those overseas machine shops. Always amazed how much they do with ancient machines and calipers. I guess if you do it for years you must get good at it!! Great video Mr.Pete. Thanks for your efforts!
I like inside calipers for precision fits in small bores which my verniers won't fit in (below 10mm).
Haven't tried using outside calipers for precision fits yet, but I like using them to quickly scan through a pile of stock to find one suitable for the job I want to do. Set the caliper for the diameter needed and just slip them over the bar stocks - if it fits, it's too small, if it doesn't you've got yourself a winner.
Great video Mr. Pete! We all have a new respect for those old calipers! 👍😀👍
Back in the 60s a fellow from a railroad repair shop came to work in our shop and he said that almost all of their repair work was done using calipers.
When reach, space, size or grime is a constraint spring calipers for the win.
My highschool shop teacher taught us this way back in the early seventies. Getting the feel consistently was hard for some kids. Make the cut and blue the piece. If you scratch off the blueing cut more. Barely making a mark and you were right on.
Always the best shorts on the web, Thanks for all the knowledge you share!
Glad you like them!
I’m sure you and I are not the only ones that had the question of the accuracy while using the calipers in those videos from overseas. Great video Mr. Pete!
I really enjoyed this. Got a couple Kennedy drawers full with these,( mostly because if I see them I buy them…. Yup it’s a sickness)Thanks for the video Mr Pete.
We both have the same illness, and must seek professional care, But the doctor is probably a golfer, and would not understand.
Nice comments regarding the skills of the overseas machinists, they work with what they have.
Thanks for doing this, I too watch the Pakistani trucker repair videos, and enjoy watching their layout and machining techniques.
Worked as a sparky in large maintenance shops and inherited a few calibers . Noticed that the younger guys never used calibers while say turning something in one of our 5 lathes. Guys who called themselves machnists in our shop that never worked a minute in a machine or tool & die shop never had halve of the tools a real deal machnists had. At least two of these guys never owned a micrometer.Thank you Mr Pete for all of the interesting & informative vidios.
Hard to believe that men who call them selves machinists do not have all the necessary tools.
Thanks for this! Great video demonstrating the differences between "make parts to fit" versus "making parts to print".
I will often use a spring caliper on my engine lathe to rough down to about .010 from final, then switch to the micrometer & sneak up on the desired. This likely from many years of wood turning spring set large to over size for quick rough down, then re set & carefully down to final.
Mr Pete, when I was an apprentice machinist early 70s, in Australia, we were trained to use calipers for all bore work. Spring calipers were not allowed, they had to be fixed jaw type. Apparently spring caliper are not as accurate as fixed.The feel that was required was " feel until you don't feel", that same feel had to be used in the outside micrometer for measurement. Very accurate work was done. All the machinists used them. Didn't see telescopics till I started a toolmakers course.
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A suggestion to help with the learning curve, machine a piece of stock to ''x'' via micrometer then set caliper via gauge block having same dimension of stock ''x'' , then familiarize yourself with the amount of drag present when checking the dimension. Practice Makes Perfect. :)
Thanks for the tips!
What you never see in those videos from third world countries machining under crude conditions is how well the repaired parts fit when re-installed. And how long they last compared to OEM parts. You do have to give credit though when someone has developed that “feel” for the work they perform. It is an art.
I second this. Being on the receiving end of such parts I found they work satisfactory, to get you out in a pinch until the real part arrives. Sometimes you need a one-time tool (e.g. special bearing/bushing puller) that the original expensive part does not justify the price.
Also, a lot of them are not really trained in machining, they just did some apprentice time and their expertise is in welding or painting. I have a lot of respect for those self-taught people. Most of them do not have the money/tools to make a truly finished part or work with hard metals.
Spring calipers are great for initial roughing since you don't have to stop the machine to measure.
Inside spring calipers are also capable of measuring internal grooves that microwave and slide calipers can't reach. I'm currently making some soft hammer faces with an internal thread, and spring calipers are the easiest way of measuring the thread relief to ensure it's deep enough. You just get a nice feel, squeeze the legs a bit to get them out of the bore, and then let them snap back to measure them.
I use my spring calipers to rough in o ring grooves on my lathe while it's running. Saves having to constantly stop and check with dial calipers or groove micrometers. It's all about feel. I don't trust it for the one thou tolerance, but it gets me to that last 10 or 20. Thanks for sharing!
Another informative and fun presentation. We all know you would never deceive us.
I use mine to rough in new parts .010 over size and let part cool, then finish machining. Learned that from an old crusty machinist born the year my 9 inch SB lathe was built.
I would love to see a video looking at the diamond tool holder. I've been thinking about getting one and would love to hear your thoughts on them
Coming soon!
I've read several places that some of the aforable hobby lathes available in England after the war didn't come with graduated dials. Yet many fine projects were done on them. I suspect a lot of the work was done using spring calipers, but without the benefit of a gauge block. Practice. I love my diamond/tangential tool holders. It's my "opinion" that most hobbyists would be much better off with high speed steel and tangential tool holder then investing in carbide. Especially for the vintage Southbends, Logan's, etc. It's just too easy to sharpen them and keep sharp with honing, rarely a need to regrind. Gary of Eccentric Engineering is a great guy, Hope to hear more about your experience with them.
I am planning videos on the diamond tool
I recall my father using an inside spring caliper to bore a recess for a press fit bearing. He had outside mics which he used to size and hold the diameter of the bearing bush. But then would pick up the bore size with the inside caliper and measure it with the micrometer. Much like a telescoping gauge being checked. And yes, the bearing was a nice firm but "in scale" final fit. Much like you I had a fun shop evening a few years back doing more or less what you did. I did some outside stuff and some inside stuff. It very much is a sense of feel and skill that takes some practice. But it didn't take long before I was hitting my sizes within .001 or less... at least most of the time....
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MrPete I've watched many of those videos from India and Pakistan of those skilled machinists making amazing things with simple measuring tools.
I've seen those Pakistani or Indian machining videos. They have huge machines! Saw one where had some kind of spring steel thing on a base that they used to indicate in a 4-jaw chuck! Interesting stuff for sure
I have always wanted to see a real demo on these types of calipers. I have a set of I/D and a set of Morphydite. The inside ones are great when there is a shaft inside the hole you are measuring. I use the roll in method similar to using snap gages. They are also friction joint and not screw type. I will be looking for a set of the friction type for O/D measuring. Just for fun. I like using the old ways. The Old timers did the walking so We can Run. It is that simple. Now we have machines that do their own calibration and measuring. What fun is that! Thanks as always Mr. Pete for bringing us along and making it interesting.
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It is nice to hear you say about the skilled machinists from India and Pakistan. There are loads of nasty comments about them but tbh I can't fault their skills working with what they have. I bet most of the comments are from people who have never used a lathe! Great video!
Well, now I will have to pull out grandpa's vintage calipers (showed back in 2019 during my quarantine quickies) and do some test runs as well. I do use his in side calipers quite often for rough in's, but of course relay on my good old Starrett's mic's and adjustable gauges for end results. Thx Lyle for doing this Short, took me back 55+ yrs this morning 🤔👍
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Very interesting. Like so many things, it's all about the feel.
Thank you.
The only thing i ever used spring calipers for was for checking the depth of o ring grooves. The work good for that
Was taught by this method before safety nazis and people actually had common sense it still serves me well. Thanks for the video
Mr. Pete, I also watch the Pakistani Truck channel and many similar ones. It's really an exceptional experience just to follow them and I often wonder what you and the other TH-cam machining
mainstays would say. Thanks for this contribution.
They also use the calipers while the machines are running, even on those enormous lathes, to measure parts 20 in. in diameter and more. I sometimes worry about them but they all still have 2 arms.
I imagine a caliper can spread and set a tiny bit with all those tight measurements, and also the friction from running measurements may shave the tips, hence the actual workpiece size may be a hair different (larger I suppose) than measured. I guess they recalibrate every few hours.
Well, they don't put the ones who lost something in the vids is all. They make ol' Lefty One Eye take the day off when the cameras are rolling. They probably get the guys who lost stuff on the right side team up with guys who lost stuff on the left. Also remember, life is pretty cheap over there. The REAL amazing part of those vids is those skilled machinists over there only get about a dollar a day, a hand full of rice and all the water they can drink from a garden hose as pay.
Thank you for showing this, and I am glad you have found a new to you method. I have entirely too many internal and external calipers (bowspring, firm joint, and others). They get a fair bit of use. Most useful for matching dimensions, such as repetitive work and duplication, but also quite useful for comparative work. Inside are also nice for centering when there is large clearance (2 inch piston rod in an 18 inch bore, for example). I rarely use them to hit a particular dimension if I can use any other measuring tool, but fairly often use them during roughing, set maybe one cut depth off final size for easy progress checks when removing a lot of material.
Great video. My shop teacher told us not to "waste shop time" using micrometers and such if calipers, rulers and machine dials were adequate for the job in hand. We were not even allowed to use precision measures for our first couple of projects (hammer, drill sharpening gauge). He had similar thoughts about using files and other hand tools before "wasting shop time" setting up a machine.
Thanks for sharing 👍 Dad taught me to stop the lathe because it wear the tips and give you a bad readings.
Once, again, Mr. Pete you have opened my eyes to a subject I thought I knew. THANK YOU
I have a drawer in one of my tool boxes dedicated to spring calipers, but the only time they ever get used is for measuring hard to access dimensions where nothing else will fit. The one that gets the most use is a 14.5" Starrett that has no model number, but does have a 1901 patent date. Thanks for the video!
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I use spring calipers all the time for bore work since I can clear the tool in the bore. getting the right "feel" to hit within .001" is pretty easy, getting to .0005" +- is a lot harder.
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I was shown a trick by an old tradesman back in the sixties, when I was an apprentice.
It works well with telescopic gauges as well. I am not as dexterous as I used to be but I can still achieve an accuracy of 0.003mm.
Hold the micrometre in your left hand so you are looking at the back of the barrel, the thimble is adjusted by one finger on that hand. The inside spring caliper is in your right hand same as when it was in the bore. Concentrate on the feel as when you were in the bore. Since you cannot read the micrometre you are not distracted by what it is reading.
Back in the day I was just as good with firm joint calipers.
Thank you, an interesting test. I have occasionally used calipers which I inherited from my grandfather who was a toolmaker in Sheffield.
It's all about "feel". It doesn't matter what measuring device you are using, OD mic. ID mic, Caliper, etc. I never let my trainees use the "clicker" on an OD mic to force them to develop the feel. I also required them to read the device while it was in contact with the work, if at all possible, as the device could move while being removed from the work.
I agree with you was about to write about touch (feel) till I seen your comment
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A lot of it is a matter of feel, even judging how measuring the part when it is still turning vs the stationary part changes the feel.
It definitely seems like a really efficient way to quickly approach your final dimension.
Mr. Pete, you are the best. I've seen these calipers and never used them. I watched right with you with an open mind and am now a believer these simple calipers have a place maybe to get you close +/- 0.010. What I hate is the risk of killing a shaft; the .947 is the worst feeling. You would need to keep gauge blocks handy I guess to use them; I love my dial calipers. Those guys in Pakistan welding and turning a broken dump truck crank in the dirt! UNBELIEVABLE!!!!!!!!!!!
Evan .499 is upsetting.
You must watch the Pakastani truck channel too Mr Pete! Great Video I often portable line bore construction machinery using spring calipers for checking where I am at during the process. With some practice you can machine surprisingly accurate with a set of calipers and a Vernier or dial caliper for a reference. Analog measurement is not dead yet!
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Great video; I had also been sharing the same doubt, especially after seeing those gentlemen truing up the stock in the chuck by using, instead of a dial test gauge, a piece of steel wire with a sharp tip :). Thanks, Mr Pete.
Yes
Not surprised at all. Ancient stone masons used to achieve very precise levels of accuracy using the most rudimentary hand tools and measurement methods. Traditionally the greatest precision was achieved with hand finishing techniques, albeit with a lot of knowledge, skill and practice.
I used to use spring calipers for aligning motor couplings regularly. I learned to use both methods in trade school and find using calipers rather than a dial gauge much faster.
Hi Mr Pete i also watch some of there videos and can't believe how they can make things like crankshafts from start to finish . no safety gear maybe not even a good pair of shoes . I don't think there quality standards would of been excepted in the USA but i could be wrong . I like seeing the gang of workers on the end of a huge pair of tongs with a red hot huck of iron in a huge hydronic hammer machine . Thanks for the videos . JM
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Thanks Mr Pete It is an interesting video. Like you when I am turning wood I use the calipers never gave it a thought about using it on turning metal.
I use my calipers a lot in the field. Great video!
This was a good one. Thank you for posting!
When I first set up a lathe at home, I had no snap gages, so calipers were the rule for inside bores. I had no problems getting within .003" using them, finer than that required a bit more finesse. Before the introduction of micrometers in the 1890's, most turning was done using calipers, usually set off of a ruler. The fellow using the lathe or planer knew the pitch of the leadscrew on the cross slide, so if it was 8 threads per inch, one turn was 1/8", one half turn was 1/16" and so on. Thousandths were not even considered. Press fits were done off the mating part. mrpete has shown how it was done back before the 1890's, it's an interesting exercise to try if you have a lathe, and if you have an older lathe without graduated dials, knowing what was shown here can make it a useful tool even in a modern home shop. Great video!
Thank you for a great useful comment
I have always been curious about the caliper method employed by the folks in that part of the world and enjoyed your demonstration. Those folks over there are, in my opinion, some pretty skilled craftsmen to do the work they do with what looks like pretty well used and dated machinery yet they are doing some pretty precise work with those calipers, it would appear. Thanks again, that was a fun video!
Good experiment. I use calipers with my wood turning, as you mentioned you have done, and it works well for the projects I have finished. But I get the need for much tighter tolerances in machining metal.
Thanks for sharing that example. I watch a lot of those videos, and I have to admit, that I kind of chuckled at the techniques that they use. But it didn't take long to realize that they were accomplishing the job, with some very fundamental tools and techniques. Like they say in racing "Run what ya brung" :)
Watching the Pakistanis work with minimal tools is a good show of how people can work under almost primitive conditions.
I think it come down to skill and years of practice. thanks Mr. Pete.
I have used the method multiple times. I especially used it with inside micrometers, where my telescoping gauge would not reach as far down in. The customer needed the bore opened up down into the bore..
I duplicated a part for a router using a crescent wrench, comparing fit & feel between the original part and the new one. That was back in 81 or 82, when Mr. Bob allowed me to add some experience to my book learning about machining. Didn't have a mic available at the time.
That’s funny, I’ve heard of a crescent wrench being used as a hammer, never as a caliper
@@mrpete222 now that i think of it, I've used big adjustable wrenches to measure driveline tubes and pipes. Also framing sqares, stacked on each other, for even larger diameter's, when fractional measurements were good enough. Like for the initial set up of drum brakes ...
1958 8th grade shop, we did not use the lathe but were supposed scrape parallel surfaces with the gage. Is all in the feeling and technique.
Awesome! Love the auction bids too.
Glad you like them!
Very interesting thank you. Hermaphrodite calipers are also handy for measure longitudinally from the faced end to the finish of a cut.
Awesome video Mr Pete thanks!
Another fantastic Video TubalCain.....best wishes from Orlando, Paul
I have a few sets of inside calipers, not sure the brand, they seem to be fairly old. Used em a few times and was happy with the results. I gave a large size outside caliper made by LS Starret. Not sure how these are sized. Overall length is 24 3/8” and across the two legs while closed the measure 15 1/8” outside to outside. Haven’t see them to machine anything because they are so large. Don’t do much work that bug. Thanks for the video Mr. Pete.
That is one heck of a big caliper
Awesome information. Thank you.
It's amazing the different ways people come up with to do precision
machine work. Great video.
The idea behind any precision turning is consistency. You hand 10 machinists spring calipers set to the same gage block, and you'll get 10 different dimensions. Also the type and quantity of the calipers will make a difference. First consideration is tolerance second is consistency. I've used this method on wood and metal patterns, but the tolerance was +/-.015". so not a big deal. Fit is the next consideration, is it a press, slip or it doesn't matter fit.
Very interesting. Thanks. I have watched some of those videos from Oakistan, possibly India. They do masterful work along with teamwork to get a job done. Unions would say they work too fast and they need more people. Ah, what would we do without unions today?
lol
Hey Mr Pete I’ve also watched a few of those videos you mentioned oil must be hard to get there I can’t believe how dry those machines are
Having worked in that part of the world, we also ran machinery with a very minimal amount of oil. The arid conditions mean that any surface wet with oil turns to grinding compound.
@@bryanbridges2519 interesting I would have never thought of that thanks
I actually use calipers quite a bit, mainly for getting close before breaking out the mic.
GREAT VIDEO! Like you, I have watched those Pakistani machinists and mechanics and marveled at the work they do with primitive tools, conditions and machines. There is always a long list of comments from the "Safety Sallys" who can't get beyond they aren't wearing steel toed boots, but if the truth were known, those guys never do anything other than watch TH-cam videos. I do much of my work using calipers and have found things work best if you stick with the same pair of calipers and don't change the way the work is held in the machine. This was a very interesting video. Thanks for producing it! With a little care and common sense, there is nothing unsafe about using a caliper "on the fly" as my old shop teacher used to call it.
Steady hands are extremely important for Brain Surgeons and Machinists : )
A good set of calipers weren't inexpensive and are precision instruments. This is another time when Prussian blue is used for precision work...the length of the amount of drag (the chord length) is measured with a scale and trigged to determine how much larger or smaller in diameter that the machined part is relative to the round part that the caliper was set to; which was also done with the thinnest smear of Prussian Blue on the contact points of the caliper. Prussian Blue used to be very important for all machinists just a few decades ago.
This method might be found in the "Machinist's Handbook" but I doubt it. I learned this one from my tool and die mentor.
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I can see this as a possibility, but calipers will "spring" to some degree when passing over the work. A machinist would need to have experience as to the friction they should feel to be accurate. I can see this being eventually acquired. Thanks.
Thanks
OK Mr Pete ... the outside calipers work, but I just don't know about taking a measurement while the machine is running, especially with those somewhat unpredictable strings of aluminum coming off. I've had this set of 10 fingers for going on 73 years and I am quite fond of them. Also, at my age I'm just not so much in a hurry I can't turn off the machine to make a measure. I might be able to walk with a wooden leg, but I'm pretty sure I can't play the guitar with wooden fingers.
Most interesting video.
Glad you enjoyed it
nice work. I've only seen David Richards use calipers for real; usually inside calipers to get around the arbor on his horizontal mills.
Interesting test Mr. Pete. I wonder if my sense of feel is good enough to do. I might give it a go and see. Thank you for sharing!
Joe
Thanks for sharing
For maximum precision micrometer measurements you should calibrate it against the gauge block. It removes most of the uncertainty in measurement.
I have some callipers. I'm going to start using them.
Very good. I will try that from time to time. Thanks
Instresting test, I think if you had a round test pin, to set your calipers on, so your feel, is comparing round with round would be more accurate. Also would your feel get better the more you practice?
Anything can be a precision instrument, if you are skilled enough.
This method will work but its definitely an acquired talent like all finesse jobs.
what they don't show you in those shops "over seas" is the finished job actually working like new in the machine they took it out of...
I saw one where they welded back together a large diesel crankshaft that had split in half... I wouldnt trust that crank past idle for more than a week... granted im sure the tolerances were so bad that assembly grease was required instead of oil
I watched that video with shock and awe. I predicted it would fail within minutes. And I’m sure it did when it went into actual every day use.
Very interesting.Thank you.
I've been really wondering about the calipers in those videos, great video idea! I'd always stopped the machine because I was thinking of the wear on the tips. I suppose measuring while running you could get caught in the chips and that might be exciting.
I have wondered that same thing. Thanks for the experiment.
Count me in the "just fine" camp. I regularly use spring calipers to get within maybe 0.010" and then start using a mic.
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