Absolutely right Keith, I agree, it's simply a matter of using the right tool for the job - very often callipers are accurate enough and more convenient.
I think you really nailed it Keith. So many have become obsessed with ultra-high precision because "we can". As you state, as long as you are within the tolerance or "spec", then use the tools that get you there the quickest. Time is money. Shop time is INCREDIBLY expensive around my area ($100/hour is NOT uncommon with 2 hour minimums usually). If there are 30 measurements needed that take 30s each with a micrometer that's $25...If the tolerances allow for it, the same could be done with the calipers the cost is
Thank you for your patience and teaching. I am a woodworker that only deals with machining when a vintage piece of equipment or a jig or tool I am making needs it, but it is very telling to see how a machinist does it. Your channel has helped me as I fumble my way through jobs that a bigger more professional shop would outsource, let alone my work now sense retirement and more DYI status.
Keith your spot on!!!!! If your working to below 1/1000 of an inch you need to interpolate material temperature to the coefficient of linear expansion for that material and what it is mating with if that material is dissimilar. I have worked in metric for the last 25 years before I retired. I had machines that could work down to 1/100 of a mm in the right hands. We never had a job come in where the tolerance was under 0.10 of a mm. Even the aeronautical work we did. Thats 0.00393701 inch and at that level its all about temperature and expansion rates. Good dial callipers or digital in the right hands are as you say are what you need to get it out the door with a happy customer. Ant. SV Impavidus.
I have 44 years building vehicle engines, machine work etc. Mr keith is 100% right, when I was building a drag racing engines I used both, normal use I go for the caliper. A test on both tools is the big thing, keeping both tools calibration right. My dad use to say build a boat like everyone wants you to and build one your own way. When they make fun of the 1st one tell them that was all their ideas and the way they said he should make it, that's why it looked so funny and is sinking. I enjoy all of keith's video's and agree, learn what works for you and your shop and do it your own way.
When you have a UA-cam channel, It is your choice on how to do things. If some viewers do not agree with your choices they should keep it to their shelves. If you have a question, yes ask it don't chastise. The creator is trying to entertain us, give them positive feedback. If you feel you can not, find something besides UA-cam to watch. Keep up the great videos Keith.
Some great thoughts Keith. I totally agree with you Keith that a micrometer is more difficult to read than a dial caliper or a digital caliper. I think for that reason, I tend to use my micrometers more often, to stay in practice. My dad was a master machinist and taught me to read a micrometer back when I was 7 or 8 years old. Back then the calipers that you saw were vernier calipers. Dad always used a micrometer to measure. If he needed less precision, he used a scale. Thanks for the great videos you turn out. Gary 76-Year-Old Home-Shop-Machinist in North West Arkansas
As a newbie with a 60 year old Atlas lathe I am tickled if I can get things within a 1/16. I use both micrometer and calipers. It reminds me of when I used a slide rule and then always checked results with a pencil Love your channel Frank
What you say about tolerances is certainly correct. I find myself spending too much time trying to make everything "Right on" when + or - .005" would be just fine. Many of the jobs that come through my shop are for farm machinery, logging machinery and odd parts for old cars. Lots of odd things. As far as digital verses dial, as many have said, the dial never runs out of battery. The only digital that I will use now are rolling digit. I recently had a pristine Mitutoyo 0 - 1" digital Mic that ate batteries within a day or so. I contacted the repair facility for a quote to repair it and was told that parts were no longer available. Be aware if you see a digital for sale. Nuff said, thanks Keith.
Ok I will put my 2 cents worth in, I am a machinist of 44 years + it has always been with me on what Measuring tool is correct for the job at hand. Yes like Keith sad its what you are comfortable with and the accuracy that you require. I my early days Vernier Callipers had fine adjustment thumb wheels like some of the older type of Vernier Height Gauges still used today. I still have 2 sets a 12" and a 24" that I still use today due to the accuracy I get using this type of calliper. Now on the use of these I find I use them more for measuring lengths of components rather than OD. This is more that the anvils on a Micrometre seat on an OD better than a Vernier Calliper. Vernier Callipers are a more versatile tool for quick measurement of OD, ID and Hole Depths in one Tool as though with a Micrometre you need a number of tools ie:- Depth Mic, internal Mic, and Std OD Mic etc as the list goes on. So Yes Keith has his point, good job Keith keep up the good work.
I Agree 100% with you Keith . Most jobs dont require .0002 accuracy .Some get so stuck on the being in the 2/10ths all the time when the job doesn't require it. I use my mitutoyo Calipers for just about every process . Micrometer is only pulled out for press/Interference ,Bearing clearances. great Video (Haters are gonna Hate ) lol
Keith, when I was being trained by some of the old timers in my shop, they had me measuring gauge blocks, feeler gauges and gauge pins just so I would develop the feel needed to accurately use those precision measuring instruments. I wouldn't trade that training investment they put into me for anything!
What gets me is that people assume that if you zero the measuring tool out at the small end it will be accurate throughout its range. Not so and especially with calipers. The dial ones can be off substantially at certain locations and spot on in others. Micrometers the same but not nearly as prone to this. To combat it when I use calipers for a specific dimension I set them to that dimension with a gage block stack. This greatly reduces error from a worn rack or gear. I have even done the same with a micrometer because the thimble thread will wear also. Just something to add to the mix to ponder.
I’m sure the nay sayers will still be there Keith, but you just keep doing things the way you do because your work is outstanding. Thanks for the video
Nice subject Keith, I updated to a new set of Kanon Vernier stainless steel calipers 40 years ago, I don't remember when the dial calipers first came into common use, I did not trust them, so at 75, I purchased a new Digital set. Takes a long time for old people to adjust.
Nicely said Keith. I have used my Mitutoyo 18 cm straight vernier with fine adjustment since my apprenticeship, it measures down to a twentieth of a millimetre, it has no sensitive dials, or batteries that go flat at inconvenient times. It is a high quality tool and I have never had a job thrown back at me because of wrong sizing.
I feel the same way about analog clocks versus digital ones. I can look at an analog clock and in just a glance I know that I have 'about five minutes' to be somewhere or do something. Whenever I see a clock at like 1:53 I don't want to have to do the math to figure out that I have exactly 7 minutes to get somewhere. I rarely need to know the time within even 1 minute accuracy.
Yes,im the same on clocks and im the same with rulers, i think imperial > metric because you can make faster reads due to known fractional graduations, a lot more than on metric sides of rulers.Strangely enough I live in a metric country but chose to use imperial if doing the drawing these days.I have always been able to use either but used to choose metric out of habit. As far as digital calipers go, about 15 feet! That's how far away the bin is.
Using your words: “You are right on the money”! More people should go your way, go as accurate as the job requires to be excelent. One foot accurate or 1 millionth, but not more nor less.
Love the educational high standard of your videoes!! As a scientist my self, i can really appreciate the presenting skills as you educate us. Thanks and keep the videoes coming. Your channel is My go to UA-cam channel for workshop inspiration :-)
As a watchmaker for the past thirty years, I remember the early seventies when the first digital quartz watches came out I could even back then feel the pain of watchmakers of the time when their customers would say, well you know these new watches are accurate to within a second per week, and the watchmakers all cringed . But some of them said why is it necessary what kind of work do you do that you need that kind of accuracy. And yet today I still get that kind of customer so I feel your pain too Keith, sure you go the extra mile when it's really needed but like you say if the job doesn't require it what's the point except to sooth your own ego maybe. Been there done that for sure. I guess we both of off a good rant today.
And then there are folks who just want a watch that keeps accurate time without the digital quartz design. These days, not that many wear wrist watches since their cell phone is their time piece. They like are those in the group that never cared that much about the watch in the first place. Then there are those who wear a wrist watch for the specific reason they were invented, to see the time within a nice piece of hardware that can have all sorts of looks. Those who still wear a wrist watch prefer them over the phone I guess. For sure the watch needs to have good time keeping as it means less fiddle-farting adjusting the time every week or month. Since the 1970's, Seiko has produced very accurate self winding watches or "automatics" until they developed the kinetic and then the spring drive which require zero winding or activity to keep wound. Finding a good watch maker today isn't easy either, just like a building contractor !
@@Garth2011 I'm glad you took the time to reply, sometimes I wonder if anyone is really out there. I think there is a time for precision and a time for beauty and sometimes they come together like in a good quality timepiece .sometimes I drag myself off on a tangent but measuring a mile down to the nearest one hundredth of an inch seems a little bit on the overkill side, and if your supposed to be at work around nine in the morning just get a timed.
I've got two clocks in the bedroom, one that's a clock radio and the other that's a indoor/outdoor weather station. That weather station sets its own clock with the WWVB signal. When I went to reset the clock radio this weekend, I discovered it was 3 minutes off, but guess what, it doesn't really matter.
@@Orxenhorf I have a WWVB clock and it takes a long time to change an hour fwd/back for some reason. Waste of time. Mechanical clocks seem to be the way to go...tick toc
I love a good automatic Seiko. There's something special knowing that it doesn't need a battery and just me wearing it is winding it. But I also love my g-shock rangeman with being solar powered and atomically controlled and updated, I think it's better than a second a week. Do I need that much accuracy for anything I do? No. Not at all. I enjoy both for what they are.
Very well presented, have done this for over 50 years. Still have a vernier caliper, no dial and although it is a bit hard to see the scales now, it still gets used sometimes. For the tightest tolerances, out come a range of micrometers.
The micrometer also has the small wheel on the end of the shaft that is a "clutch" that will give the same resistance when measuring. Some folks don't use it but it is there and can be adjusted I believe to turn less or more into the subject part being measured. Once it is set to your preferred tightness, it will do that with every measurement which provides a more consistent outcome from one part to another.
One advantage to the dial caliper is that it will do inside measurements as well as outside. But the micrometer has a certain beauty that can't be denied. I love both. And I show my grandkids how to check either against a gage block.
They make inside measuring micrometers too. A couple of different styles are available. Not sure if they are technically as accurate as the outside ones though because of the basic design needs possibly introducing more flex. But they're what is often used for measuring things like bearing journals and bores, so they must be good enough. An outside C style micrometer is about a rigid as you can get.
Keith, glad you have a stiff upper lip. You know what you are doing and it is hard to offer advice to a man in your shoes. Keep in mind that most that "tell you what to do" have little experience or do not watch what you are capable of. Thanks for being humble.
Hey Keith! In reference at 08:09 about Time and Money reminded me of a little tirade about who earns how much and why...To wit... The "Salary Theorem" states that "Engineers, scientists, and teachers can never earn as much as business executives and sales people." This theorem can now be proved by mathematics based on two postulates: Postulate 1: Knowledge is Power. Postulate 2: Time is Money. As any engineer knows: Power = Work / Time Since: Knowledge = Power, and Time = Money Then: Knowledge = Work / Money. Multiplying both quantities by Money we get... Money * Knowledge = Work Re-arranging by dividing both sides by Knowledge reveals... Money = Work / Knowledge. Which provides that as Knowledge increases, Money decreases... Conversely, as Knowledge decreases Money increases! Thus, as Knowledge approaches zero, Money approaches infinity, regardless of the amount of work done. Conclusion: The less you know, the more you make. LOL!
I find the mic to square itself to the work much better than calipers. But if you have that feel for calipers then they read just as well. And I can carry a whole set of mics in one 12" caliper
Kieth, I agree with you completely about the use of calipers vis-a-vis micrometers, but I prefer digital to analog. In this situation, Chinese instruments are not viable. They tend to consume batteries way too fast and provide erratic readings. Quality digital instruments, like Mitutoyo, are faster to use and eliminate some all too common human error issues which plague their analog counterparts. As an analogy, though quality work can be done on a manual mill using the dials, once you've used a DRO you wouldn't go back to analog;-)
Nothing wrong with your explanation Keith. Calipers are also know as guess-o-meters, especially the old slide type, which I can no longer read accurately. I never liked the dial calipers but do use digital calipers these days. I use them while witling away material. Under 0.050" I use micrometers. It is the way we were taught.
Keith, spot on. Period. Why spend the effort to hold 0.0001 tolerance when the print says +/- 0.003 "sigh". I use both, and use the calipers 70% of the time, and the mics 30% of the time. I am comfortable with and use both, exactly the way you do.
I once had a young technical assistant (I am a retired molecular biologist) who insisted on using an analytical balance (accuracy 0.0001g) to weigh out a substance to make a 0.5% solution. I told here to use a regular lab balance, but she insisted on the analytical balance. I looked at the solution, which had a yellow colour and noticed that it was much too dark. I checked the concentration and it was not 0.5%, but something more than 4%. She weighed to 0.00001, but set the tare wrong and was off by a factor of 8. The higher the precision of a measuring instrument the easier it is to make a serious error. If you don't need 0.0001x accuracy, don't use an instrument that will measure to that accuracy. It's a waste of time and can lead to errors.
I was shocked that you didn't mention a plastic ruler! When I am turning an axle for a hit-n-miss engine cart to fit the 1912 or so cast iron wheels (usually) rusty, I seldom use my micrometer. Ok, just kidding. But like you said depending on the project will dictate the tools to use. Old Tony did a video on the vernier scale caliper, which has both inch and metric. I was impressed and went to eBay and bought one. Again like you said after a little use I can come vert close for my typical measurements. Finally, yes I have both digital and dial calipers, both of good quality. To my surprise I have a Shars dial caliper which has 2 hands for inch and one for metric: Guess what, mine at least, is right on the mark.
Forty years ago when I could see, my favorite was a vernier caliper. I had a dial caliper once. And I never trusted a digital readout that needs battries. When it really has to count you just cant beat the old C clamp. I had Starrett micrometers up to 12 inch. I enjoy your videos Keith, you do a great job.
Not 40 years since i could read my vernier calipers properly but i have come to love dials since.I honestly hated them when my eyes worked properly, now i have 5 or 6 different flavours floating around the place.I guess digital calipers may be good for a carpenter or painter maybe? I must say though a friend has some mitutoyo diamond series vernier calipers and i dont seem to have as much of an issue (only used them briefly with no standards on hand) with the supposedly "parralax free" scale on them,both of us should probably check them out!
I put on my right shoe first then my left. I then tie the right then the left. I am very used to that procedure and it works very well for me. I'm 72 years old and have lots of practice... kinda like what Keith was telling us. OK, here is one for discussion, left handed people are dangerous around a running lathe (not really after they get used to that, right)! Greg
Heretic! Always put the left shoe on first, then the right, then tie the left, tie the right. There was a scene in All in the Family where Mike and Archie are arguing about sock-sock, shoe-shoe or sock-shoe, sock-shoe. We can always find something to argue about. Hope you have a great day!
You're wrong wrong wrong about lefties on a lathe. Because we are used to using both hands in this world that you righties made for us, we can deal with the things on any machine tool that need a left hand. We are actually safer than the crippled folks that normally only use the right hand! Just kidding guys. I do feel very comfortable on machine tools though.
The trick is knowing where your hands are at all times. This is true with using any machine. Keeping track of where you are in relationship to the machine and it's moving parts is vital. When you lose track of where you are in relationship to the Machine is when you get hurt. Pay attention, and it could save your life. And don't work if you're tired or frustrated. And it doesn't matter if you are left or right handed. You need both hands. Learn to work with either hand.
good explanation keith. i believe most calipers today can be very accurate . they are pretty much an indispensable tool . i also believe its all about technique. it can be very difficult to get an accurate reading from a piece of stock in a lathe..that takes practice. squeezing ,canting or pulling the calipers off at an angle will change your readings. i like to use them to get close to my final dimension and then switch to a mic.i just don't trust myself to use calipers down to the last thou or two. and its not the fault of the tool.
I totally agree with with what you’re talking about, after all in ancient times the tools amounted to where string and wood and in there time was just about as accurate as it could be to them, so some people want to get off their high horse and think about the people who have only got a piece of string and a bit of wood. 🏴
A micrometer is intrinsically more accurate because it's scale is inline with it's measuring points, whereas with the caliper they are offset. Having said that, as you correctly say, it all depends on the tolerance you need for the job in hand. I think for the homeshopist you should always aim for precision, not because it is necessary but because it takes practice to achieve and so you can be in practice for when, or if, it is crucial. Although frequently near enough is good enough so don't fret over microns when fitting a barn door. ☺
Seriously! Years ago I had a "Temp" gig at a plastics company. They did vacuum forming. Drawings had no tolerance specified which means +/- .001". They had two dial calipers. One had been dropped and the crystal was broken Shop Foreman asked me if I had broken it and I said: "I DON'T DROP TOOLS! It was like that when I picked it up!" PITA job. I didn't EVEN offer to bring MY tools there because they didn't pay me enough!
I am a machinist as well but I'm always looking for new practical tips and tricks to help make my work easier and better. I also enjoy seeing the old machines and trains that you deal with. I'm retired now but I'm still very active, I wish I were closer to you because I'd love to get involved in some of the restorations!!! I used to do a lot of videography in my spare time but now it's mostly just machine work and electronic control systems. Anyway, I wouldn't say that calipers aren't as accurate as micrometers, it's just that micrometers offer a higher level of resolution since they have a vernier scale for 10ths. I can often guess to within a 10th or 2 how many 10ths are involved by looking at how the needle is situated between the marks on a set of dial calipers and I'm certain that you can too. I usually only get out my micrometers if I need to measure in 10ths or if the part is too large in diameter for calipers. IMHO, viewers that harp about something like that MUST NOT do any machining themselves, otherwise they'd know how impractical and silly it would be to use micrometers for most everything. Again though, if a part is too large in diameter to use dial calipers, then the best choice is to use the appropriate sized micrometer even for low tolerances. I have enjoyed watching your channel as well as Adam Booth's and Tom Lipton's :-D Thanks, Keith!! Joe
Keith, very well said. What are you measuring...that is the key. I wish that PBS would pick up your show like they did with Norm Abrams. Please continue to make videos.
I'm kinda thinking that if someone has a set of gauge pins, then they are already comfortable measuring with either tool. But, your point is to take a known item and practice measuring it. This is excellent advice. If you don't know what the exact measurement is, you can practice getting the same measurement over and over, but if you don't know what it's supposed to measure, you don't know if you are doing it right and maybe you cranked down too hard. This would actually build a bad habit and would cause troubles when building to spec. But if you are building a copy, your measuring tool doesn't even need to be calibrated.
If I've been using the same dial caliper for any length and know the feel of them I've felt comfortable working to .0005'. I've seen a good saw man cut consistently within .005" using a tape measure. It's all about how much you trust yourself.
Great video! I have only been working (playing) at this for a couple of years, so I am still a long way off of building precision parts. However, as a craftsman building all sorts of wooden/metal/pastic/stone/etc things over the years I can totally relate to your take. 95% of the stuff I build can be within 1/8"--1/4" . 4.9% of the time I need it down to a 32nd or 64th. And that last .1 % well lets just say I might bump or bend or tweak to get there. I can remember very few times in my life that things had to be ultra precise. Moral of the story, measure/build to the needs of the situation. Theres a big difference in framing a house and building a rocket ship.
Well said on your side Keith. In my defense, I guess too many decades making military spec parts and pharmaceutical parts has me doing all my precision measuring with a micrometer. I will add if anyone is going to use their calipers as their "go to" measuring tool, make sure you check out the jaws with a gage block to see if there is any wear towards the tips. Jeff
I had to read a far ways down the page before I found some guys commenting about checking their measurements while roughing out with calipers, then switching over to the micrometer for the fine measurements at the end. It's as Keith says, the calipers are faster, and often good enough. Another topic which I see is about why a micrometer is generally capable of finer readings than a dial caliper. The way that I phrase that is that you can get more threads per inch on a screw than teeth per inch on a rack with a pinion gear, and you get a longer sliding distance by making the scale wrap around a spiral. That said, vernier calipers don't have gears, and can be more accurate than dial calipers - at the cost of time spent reading them. But, the scale slides on a straight line, so you have practical limitations. The various scales used by digital calipers can have some advantages in readability over the vernier scale, at the cost of being a bit fussy about holding zero and eating battery charge... which doesn't always correlate to the purchase price or the name on the label... It all depends, and personal preferences aside, what tolerances are good enough for any given job... I used to work at an optical electronics operation as a very young engineer, and had designed some parts where thermal expansion had to open a very accurate gap of a couple of thousandths of an inch for the electrodes to function optimally. The gap was incredibly narrow, and given that the parts were welded into an assembly, the pre-sets had to be very carefully fabricated in order to minimize the infant mortality and trashing of the rather expensive materials that make even more expensive assemblies. Since this was for a development project, my work got assigned to a drafter who came from a temp agency, and what little experience he had was with making mass produced parts. You could hear my roar of anger over half of the second floor (or so I was told!) when I got the checkprint and found that he had taken it upon himself to "correct" my design tolerances for me, "because nobody can hold tolerances so tight" as he lectured the "impractical and inexperienced" junior engineer... He was still very smug and self-satisfied when the drafting department manager and his deputy came by to see why I was going off... something about not asking me first about why I need the parts held to such tight tolerances, and then trying to lecture the engineer rather than discuss the design on a point-by-point basis to understand the reasoning behind *why* my parts were a bit exotic... It only took about a minute for him to lose his self-satisfied mindset after these two worthies arrived... At the other end of the spectrum I've designed equipment for bulk materials handling and industrial ventilation where +/- 1/8" (or more) is more than close enough...
Agreed... serious issue... :) I have a secure space for both tools - and they never get back there... I really need to mount them somehow above my work bench... Hint - metric micrometers are simpler :) but calipers are wonderful for fairly accurate reads.
The worst thing with calipers is that people tend to angle them instead of looking for the lowest measurement on O.D. or the highest on I.D. The other problem is not knowing if the inside and outside are reading the same (somebody dropped them). when sneaking up on a tolerance fit, the calipers are out.
Thanks! I'm not a machinist but have used both calipers and micrometers. The first thing I notice is how you keep the calipers in a box. That might be part of why yours are accurate even after heavy use. It might be time-wasting overkill, but I used to check both for zero reading when they are closed. What do you think? Many of the micrometers come with a little spanner wrench for zero setting.
I recently machined a spacer block / bracket. The only dimension I even measured was the hole spacing, and I did that with a ruler. I could have done it by marking the spacing on a piece of paper, and transfering that to the workpiece. Even dial calipers were overkill. The part worked and looked fine the first try. Don't buy a laser interferometer if the tolerances are +/- 1/4 inch (6 mm).
cnc stuff is harder to measure accurately with just calipers, because the parts are more complicated. like a shallow face groove in a piece of stainless, if you try to use the calipers they will dig in and flex too much to get an accurate measurement, sometimes you just need other tools like an inside mic. Definitely for +/- 0.0005"
Given the nature of this channel (vintage machinery), and the fact that the tolerances used to build that machinery 80-100 years ago, I can understand Keith's point about dial calipers. If your building a nuclear reactor, get out the micrometer....
@@steveredenbaugh9058 No. It is micrometer that has a window with digits that are visible. It is mechanical, and the numbers are printed on a wheel that turns and read through a window.
Do what is required for the job. For others to criticize when you are the one doing the work and the job works out; nothing else matters including the obsessive compulsive use of too accurate a measuring tool.
We used to say that the definition of an engineer is: calculate to a ten thousandth, Mark it with a piece of chalk, cut it off with an axe. Like you say, it depends
Thanks Keith, ... This is exactly how I think on the subject. Yes, tracking alignment with a dial is way better than digital. The dial paints a picture, digital is just a range of changing numbers, ..... good luck on that?
Just like many others I use both depending on the work and tolerances required. Is it great to turn a part to 1.25000 inches, yes. However if the spec sheet says 1.250 + - .005 is it really necessary?
Even the cheap electronic Chinese calipers for $10 can measure quite accurately - to 0.001 if you know how to measure. People get these, abuse them and then say they are crap. Once you realize that its all in the feel and pressure you apply you get good results. Also need to zero them often. Dial calipers are nice as well but more fragile - once you drop them on an end or front when open they are damaged. Micrometers are cool but very slow to measure and without much practice not much more accurate then caliper. Most work in hobby machine shop is not in need of accuracy beyond 0.001. Only reason to do such accurate work would be to have some fun trying to hit the number.
Sorry WD, but the mechanical design of dial calipers doesn't and won't allow that level of consistent repeatable accuracy. The industry standard for high quality measuring equipment is always a repeatability of + - one count of the tools resolution. Or + - one thou on .001" reading dial calipers. And what a tools dial or display shows isn't it's repeatable accuracy level. How many divisions or digits there are is called the tools resolution. It's repeatable accuracy and that resolution are not even close to being the same thing. My Mit digitals will display to 1/2 a thou I ignore that number since it's meaningless.You could build a large faced set of dial calipers using the same standard design and put 10ths divisions on it, the tools internal mechanical design still can't repeat or be any more accurate unless that mechanical design is changed to allow that level of accuracy. At one time I believe Starrett and maybe a few others did try making special 10ths reading calipers quite a few years ago. I recall reading they were selling for well over $3k, mikes are a lot cheaper and more durable so almost no one bought them. And a caliper can be that allowed + - one count out on accuracy and they will still pass through even Starrett's, Mitutoyo's, Mahr's etc QC checks. Mostly the equipment will or should do better than that. On average with anything I've checked against gauge blocks it's usually but not always about half of the allowed deviation. A set of calipers has some small but very important clearances to allow the tools measurement assembly to even move. Those non optional clearances allow the moving jaw to very very slightly rock out of squareness with the fixed jaw no matter how well there made or by who. For the best and most accurate technique Mitutoyo states that the thumb wheel isn't used. Your supposed to gently squeeze the moving jaw and fixed jaw between your thumb and fore finger for smaller diameters and use both hands to do the same on larger parts. And using a consistent closing pressure every time is important. For round parts that closing pressure should be centered on the calipers jaws where they touch the diameters C/L. It's within feasibility one single measurement just might be able to be read to that half or third of a thou and even be correct. And the next 5 or 100 measurements might be well off that. That's the problem with them, you just don't know when there out to more than that half / third of a thou or by how much. I've checked myself and my calipers more than enough under ideal conditions on very good gauge blocks using the best techniques I know of, and calipers can not be depended on to that level of accuracy. There design makes doing so mechanically impossible. They simply can't repeat well enough to where I'd ever bet real money on even which exact thou there reading to never mind half or thirds of a thou. My solar powered Mits are the tightest yet smoothest pair of calipers as well as repeating to the best level I've seen so far. They'll beat either of my 6" or 12" Mit. dial calipers easily for there repeatable accuracy. They can almost always repeat to about a thou and sometimes less on those gauge blocks under those ideal conditions if I do my part. But if it has to be within .003" or less I always use a mike. Many might chose to disbelieve some or all of the above. You sure don't need to take my word for this, no ones stopping anyone from doing there own research about it. There's lots of free information on metrology manufacturers websites that will back up anything I've said.
@@turningpoint6643 Thanks for your treatise. You've used a large number of words to tell me I cannot do something that I know I can do. Give me two well made standards,, one at 0.5000 and the other at 0.5005 and my Mitutoyo calipers will pick up their difference easily.
@@wdhewson Great response, but it doesn't matter if you can tell the difference between half thou jo blocks. The tolerance dictates the tool. And I'm certain you wouldn't measure a .3937" +.0008/-0 dimension with a caliper, regardless of how nice or reliable you find them. It would be like slot milling with a cut tap...yes it CAN be done, but it's not good machining practice.
It does depend on the caliper, on some of mine they have 200thou per rotation dials, those are not so easy to get consistent below 1 thou but my 100thou one 1/2 is easy.Ive never needed to go below that and thats only one specific job that i repeat often,more than enough to know that A i am getting consistent output and b:its showing in the data garnered.Im only talking about quality tools,no chineesium.
Absolutely right Keith, I agree, it's simply a matter of using the right tool for the job - very often callipers are accurate enough and more convenient.
I don't understand how anyone can fault Uncle Keith when he has so many wonderful successes in the shop.
It's the internet. Inevitably some keyboard experts will mouth off about things they know nothing about.
I think you really nailed it Keith. So many have become obsessed with ultra-high precision because "we can". As you state, as long as you are within the tolerance or "spec", then use the tools that get you there the quickest. Time is money. Shop time is INCREDIBLY expensive around my area ($100/hour is NOT uncommon with 2 hour minimums usually). If there are 30 measurements needed that take 30s each with a micrometer that's $25...If the tolerances allow for it, the same could be done with the calipers the cost is
Thank you for your patience and teaching. I am a woodworker that only deals with machining when a vintage piece of equipment or a jig or tool I am making needs it, but it is very telling to see how a machinist does it. Your channel has helped me as I fumble my way through jobs that a bigger more professional shop would outsource, let alone my work now sense retirement and more DYI status.
Keith your spot on!!!!! If your working to below 1/1000 of an inch you need to interpolate material temperature to the coefficient of linear expansion for that material and what it is mating with if that material is dissimilar. I have worked in metric for the last 25 years before I retired. I had machines that could work down to 1/100 of a mm in the right hands. We never had a job come in where the tolerance was under 0.10 of a mm. Even the aeronautical work we did. Thats 0.00393701 inch and at that level its all about temperature and expansion rates. Good dial callipers or digital in the right hands are as you say are what you need to get it out the door with a happy customer. Ant. SV Impavidus.
I have 44 years building vehicle engines, machine work etc. Mr keith is 100% right, when I was building a drag racing engines I used both, normal use I go for the caliper. A test on both tools is the big thing, keeping both tools calibration right. My dad use to say build a boat like everyone wants you to and build one your own way. When they make fun of the 1st one tell them that was all their ideas and the way they said he should make it, that's why it looked so funny and is sinking. I enjoy all of keith's video's and agree, learn what works for you and your shop and do it your own way.
Gday Keith, your spot on, it’s whatever your are more comfortable with, thank you for taking the time to set the issue straight, ATB Matty
Great video Keith - I appreciate your honesty and integrity with all the work you do.
When you have a UA-cam channel, It is your choice on how to do things. If some viewers do not agree with your choices they should keep it to their shelves. If you have a question, yes ask it don't chastise. The creator is trying to entertain us, give them positive feedback. If you feel you can not, find something besides UA-cam to watch. Keep up the great videos Keith.
I know the "keep it to their shelves" is a typo, but by happy coincidence it is completely accurate.
@@Dwarfracer88 Illiterate grammatical
@@harpomarx7777 Ironically, your comment is grammitically wrong.
Some great thoughts Keith. I totally agree with you Keith that a micrometer is more difficult to read than a dial caliper or a digital caliper. I think for that reason, I tend to use my micrometers more often, to stay in practice. My dad was a master machinist and taught me to read a micrometer back when I was 7 or 8 years old. Back then the calipers that you saw were vernier calipers. Dad always used a micrometer to measure. If he needed less precision, he used a scale.
Thanks for the great videos you turn out.
Gary 76-Year-Old Home-Shop-Machinist in North West Arkansas
As a newbie with a 60 year old Atlas lathe I am tickled if I can get things within a 1/16.
I use both micrometer and calipers. It reminds me of when I used a slide rule and then always checked results with a pencil
Love your channel
Frank
Got my slide rule out, checked it over; have forgotten how to use it. Bought it around 60 years ago, dont need it for my pension!
Like you said Keith it depends on what you are doing and you feel comfortable with your measurement.
What you say about tolerances is certainly correct. I find myself spending too much time trying to make everything "Right on" when + or - .005" would be just fine. Many of the jobs that come through my shop are for farm machinery, logging machinery and odd parts for old cars. Lots of odd things. As far as digital verses dial, as many have said, the dial never runs out of battery. The only digital that I will use now are rolling digit. I recently had a pristine Mitutoyo 0 - 1" digital Mic that ate batteries within a day or so. I contacted the repair facility for a quote to repair it and was told that parts were no longer available. Be aware if you see a digital for sale. Nuff said, thanks Keith.
Ok I will put my 2 cents worth in, I am a machinist of 44 years + it has always been with me on what Measuring tool is correct for the job at hand. Yes like Keith sad its what you are comfortable with and the accuracy that you require. I my early days Vernier Callipers had fine adjustment thumb wheels like some of the older type of Vernier Height Gauges still used today. I still have 2 sets a 12" and a 24" that I still use today due to the accuracy I get using this type of calliper. Now on the use of these I find I use them more for measuring lengths of components rather than OD. This is more that the anvils on a Micrometre seat on an OD better than a Vernier Calliper. Vernier Callipers are a more versatile tool for quick measurement of OD, ID and Hole Depths in one Tool as though with a Micrometre you need a number of tools ie:- Depth Mic, internal Mic, and Std OD Mic etc as the list goes on. So Yes Keith has his point, good job Keith keep up the good work.
I Agree 100% with you Keith . Most jobs dont require .0002 accuracy .Some get so stuck on the being in the 2/10ths all the time when the job doesn't require it. I use my mitutoyo Calipers for just about every process . Micrometer is only pulled out for press/Interference ,Bearing clearances. great Video (Haters are gonna Hate ) lol
Keith, when I was being trained by some of the old timers in my shop, they had me measuring gauge blocks, feeler gauges and gauge pins just so I would develop the feel needed to accurately use those precision measuring instruments. I wouldn't trade that training investment they put into me for anything!
What gets me is that people assume that if you zero the measuring tool out at the small end it will be accurate throughout its range. Not so and especially with calipers. The dial ones can be off substantially at certain locations and spot on in others. Micrometers the same but not nearly as prone to this. To combat it when I use calipers for a specific dimension I set them to that dimension with a gage block stack. This greatly reduces error from a worn rack or gear. I have even done the same with a micrometer because the thimble thread will wear also. Just something to add to the mix to ponder.
I’m sure the nay sayers will still be there Keith, but you just keep doing things the way you do because your work is outstanding. Thanks for the video
Nice subject Keith, I updated to a new set of Kanon Vernier stainless steel calipers 40 years ago, I don't remember when the dial calipers first came into common use, I did not trust them, so at 75, I purchased a new Digital set. Takes a long time for old people to adjust.
Nicely said Keith. I have used my Mitutoyo 18 cm straight vernier with fine adjustment since my apprenticeship, it measures down to a twentieth of a millimetre, it has no sensitive dials, or batteries that go flat at inconvenient times. It is a high quality tool and I have never had a job thrown back at me because of wrong sizing.
I feel the same way about analog clocks versus digital ones. I can look at an analog clock and in just a glance I know that I have 'about five minutes' to be somewhere or do something. Whenever I see a clock at like 1:53 I don't want to have to do the math to figure out that I have exactly 7 minutes to get somewhere. I rarely need to know the time within even 1 minute accuracy.
Yes,im the same on clocks and im the same with rulers, i think imperial > metric because you can make faster reads due to known fractional graduations, a lot more than on metric sides of rulers.Strangely enough I live in a metric country but chose to use imperial if doing the drawing these days.I have always been able to use either but used to choose metric out of habit. As far as digital calipers go, about 15 feet! That's how far away the bin is.
Using your words: “You are right on the money”! More people should go your way, go as accurate as the job requires to be excelent. One foot accurate or 1 millionth, but not more nor less.
Good and fair comparison that needed to be said. But as with any measuring device, check calibration and zero frequently.
I totally agree with your thoughts on this subject. Totally depends on the requirements you are looking at. Carry on Sir!
Love the educational high standard of your videoes!! As a scientist my self, i can really appreciate the presenting skills as you educate us. Thanks and keep the videoes coming. Your channel is My go to UA-cam channel for workshop inspiration :-)
As a watchmaker for the past thirty years, I remember the early seventies when the first digital quartz watches came out I could even back then feel the pain of watchmakers of the time when their customers would say, well you know these new watches are accurate to within a second per week, and the watchmakers all cringed . But some of them said why is it necessary what kind of work do you do that you need that kind of accuracy. And yet today I still get that kind of customer so I feel your pain too Keith, sure you go the extra mile when it's really needed but like you say if the job doesn't require it what's the point except to sooth your own ego maybe. Been there done that for sure. I guess we both of off a good rant today.
And then there are folks who just want a watch that keeps accurate time without the digital quartz design. These days, not that many wear wrist watches since their cell phone is their time piece. They like are those in the group that never cared that much about the watch in the first place. Then there are those who wear a wrist watch for the specific reason they were invented, to see the time within a nice piece of hardware that can have all sorts of looks. Those who still wear a wrist watch prefer them over the phone I guess. For sure the watch needs to have good time keeping as it means less fiddle-farting adjusting the time every week or month. Since the 1970's, Seiko has produced very accurate self winding watches or "automatics" until they developed the kinetic and then the spring drive which require zero winding or activity to keep wound. Finding a good watch maker today isn't easy either, just like a building contractor !
@@Garth2011 I'm glad you took the time to reply, sometimes I wonder if anyone is really out there. I think there is a time for precision and a time for beauty and sometimes they come together like in a good quality timepiece .sometimes I drag myself off on a tangent but measuring a mile down to the nearest one hundredth of an inch seems a little bit on the overkill side, and if your supposed to be at work around nine in the morning just get a timed.
I've got two clocks in the bedroom, one that's a clock radio and the other that's a indoor/outdoor weather station. That weather station sets its own clock with the WWVB signal. When I went to reset the clock radio this weekend, I discovered it was 3 minutes off, but guess what, it doesn't really matter.
@@Orxenhorf I have a WWVB clock and it takes a long time to change an hour fwd/back for some reason. Waste of time. Mechanical clocks seem to be the way to go...tick toc
I love a good automatic Seiko. There's something special knowing that it doesn't need a battery and just me wearing it is winding it. But I also love my g-shock rangeman with being solar powered and atomically controlled and updated, I think it's better than a second a week. Do I need that much accuracy for anything I do? No. Not at all. I enjoy both for what they are.
Very well presented, have done this for over 50 years. Still have a vernier caliper, no dial and although it is a bit hard to see the scales now, it still gets used sometimes. For the tightest tolerances, out come a range of micrometers.
The micrometer also has the small wheel on the end of the shaft that is a "clutch" that will give the same resistance when measuring. Some folks don't use it but it is there and can be adjusted I believe to turn less or more into the subject part being measured. Once it is set to your preferred tightness, it will do that with every measurement which provides a more consistent outcome from one part to another.
One advantage to the dial caliper is that it will do inside measurements as well as outside. But the micrometer has a certain beauty that can't be denied. I love both. And I show my grandkids how to check either against a gage block.
They make inside measuring micrometers too. A couple of different styles are available. Not sure if they are technically as accurate as the outside ones though because of the basic design needs possibly introducing more flex. But they're what is often used for measuring things like bearing journals and bores, so they must be good enough. An outside C style micrometer is about a rigid as you can get.
I use the calipers mostly inside outside and depth in one tool, the mike is the tool for spot on jobs but the very near caliper is my goto option
Keith, glad you have a stiff upper lip. You know what you are doing and it is hard to offer advice to a man in your shoes. Keep in mind that most that "tell you what to do" have little experience or do not watch what you are capable of. Thanks for being humble.
Hey Keith!
In reference at 08:09 about Time and Money reminded me of a little tirade about who earns how much and why...To wit...
The "Salary Theorem" states that "Engineers, scientists, and teachers can never earn as much as business executives and sales people."
This theorem can now be proved by mathematics based on two postulates:
Postulate 1: Knowledge is Power.
Postulate 2: Time is Money.
As any engineer knows: Power = Work / Time
Since: Knowledge = Power, and Time = Money
Then: Knowledge = Work / Money.
Multiplying both quantities by Money we get...
Money * Knowledge = Work
Re-arranging by dividing both sides by Knowledge reveals...
Money = Work / Knowledge.
Which provides that as Knowledge increases, Money decreases...
Conversely, as Knowledge decreases Money increases!
Thus, as Knowledge approaches zero, Money approaches infinity, regardless of the amount of work done.
Conclusion: The less you know, the more you make.
LOL!
Right on Keith! Couldn't agree more
Thanks Kieth !! Mark
Well said Keith. Exactly the same way I measure things.
I find the mic to square itself to the work much better than calipers. But if you have that feel for calipers then they read just as well. And I can carry a whole set of mics in one 12" caliper
Kieth, I agree with you completely about the use of calipers vis-a-vis micrometers, but I prefer digital to analog. In this situation, Chinese instruments are not viable. They tend to consume batteries way too fast and provide erratic readings. Quality digital instruments, like Mitutoyo, are faster to use and eliminate some all too common human error issues which plague their analog counterparts.
As an analogy, though quality work can be done on a manual mill using the dials, once you've used a DRO you wouldn't go back to analog;-)
Nothing wrong with your explanation Keith. Calipers are also know as guess-o-meters, especially the old slide type, which I can no longer read accurately. I never liked the dial calipers but do use digital calipers these days. I use them while witling away material. Under 0.050" I use micrometers. It is the way we were taught.
Keith, spot on. Period. Why spend the effort to hold 0.0001 tolerance when the print says +/- 0.003 "sigh". I use both, and use the calipers 70% of the time, and the mics 30% of the time. I am comfortable with and use both, exactly the way you do.
I once had a young technical assistant (I am a retired molecular biologist) who insisted on using an analytical balance (accuracy 0.0001g) to weigh out a substance to make a 0.5% solution. I told here to use a regular lab balance, but she insisted on the analytical balance. I looked at the solution, which had a yellow colour and noticed that it was much too dark. I checked the concentration and it was not 0.5%, but something more than 4%. She weighed to 0.00001, but set the tare wrong and was off by a factor of 8. The higher the precision of a measuring instrument the easier it is to make a serious error. If you don't need 0.0001x accuracy, don't use an instrument that will measure to that accuracy. It's a waste of time and can lead to errors.
This is why a lot of good engineers mark out with height gauges, verniers, gauge blocks etc, but do a "reality check" with a simple 6" ruler
Very good explanation, I’m not a machinist and you made sense to me.
I was shocked that you didn't mention a plastic ruler! When I am turning an axle for a hit-n-miss engine cart to fit the 1912 or so cast iron wheels (usually) rusty, I seldom use my micrometer. Ok, just kidding. But like you said depending on the project will dictate the tools to use. Old Tony did a video on the vernier scale caliper, which has both inch and metric. I was impressed and went to eBay and bought one. Again like you said after a little use I can come vert close for my typical measurements. Finally, yes I have both digital and dial calipers, both of good quality. To my surprise I have a Shars dial caliper which has 2 hands for inch and one for metric: Guess what, mine at least, is right on the mark.
A spot on common sense approach to measurement, know what accuracy is required and pick a measurement tool and method to suit.
Keith you thoughts are correct unless you are building parts for the space shuttle the calipers are ok.
Forty years ago when I could see, my favorite was a vernier caliper. I had a dial caliper once. And I never trusted a digital readout that needs battries. When it really has to count you just cant beat the old C clamp. I had Starrett micrometers up to 12 inch. I enjoy your videos Keith, you do a great job.
Not 40 years since i could read my vernier calipers properly but i have come to love dials since.I honestly hated them when my eyes worked properly, now i have 5 or 6 different flavours floating around the place.I guess digital calipers may be good for a carpenter or painter maybe? I must say though a friend has some mitutoyo diamond series vernier calipers and i dont seem to have as much of an issue (only used them briefly with no standards on hand) with the supposedly "parralax free" scale on them,both of us should probably check them out!
I put on my right shoe first then my left. I then tie the right then the left. I am very used to that procedure and it works very well for me. I'm 72 years old and have lots of practice... kinda like what Keith was telling us. OK, here is one for discussion, left handed people are dangerous around a running lathe (not really after they get used to that, right)! Greg
Heretic! Always put the left shoe on first, then the right, then tie the left, tie the right.
There was a scene in All in the Family where Mike and Archie are arguing about sock-sock, shoe-shoe or sock-shoe, sock-shoe. We can always find something to argue about. Hope you have a great day!
You're wrong wrong wrong about lefties on a lathe. Because we are used to using both hands in this world that you righties made for us, we can deal with the things on any machine tool that need a left hand. We are actually safer than the crippled folks that normally only use the right hand!
Just kidding guys. I do feel very comfortable on machine tools though.
The trick is knowing where your hands are at all times. This is true with using any machine. Keeping track of where you are in relationship to the machine and it's moving parts is vital. When you lose track of where you are in relationship to the Machine is when you get hurt. Pay attention, and it could save your life. And don't work if you're tired or frustrated. And it doesn't matter if you are left or right handed. You need both hands. Learn to work with either hand.
@@timothyball3144 I love it!! To each his own: no law no imputed sin...or is there? Greg
Good one Keith.
good explanation keith. i believe most calipers today can be very accurate . they are pretty much an indispensable tool . i also believe its all about technique. it can be very difficult to get an accurate reading from a piece of stock in a lathe..that takes practice. squeezing ,canting or pulling the calipers off at an angle will change your readings. i like to use them to get close to my final dimension and then switch to a mic.i just don't trust myself to use calipers down to the last thou or two. and its not the fault of the tool.
I totally agree with with what you’re talking about, after all in ancient times the tools amounted to where string and wood and in there time was just about as accurate as it could be to them, so some people want to get off their high horse and think about the people who have only got a piece of string and a bit of wood. 🏴
Well said. It’s all about the tolerances.
A micrometer is intrinsically more accurate because it's scale is inline with it's measuring points, whereas with the caliper they are offset. Having said that, as you correctly say, it all depends on the tolerance you need for the job in hand.
I think for the homeshopist you should always aim for precision, not because it is necessary but because it takes practice to achieve and so you can be in practice for when, or if, it is crucial. Although frequently near enough is good enough so don't fret over microns when fitting a barn door. ☺
Wow, jealous of that surface plate you're working on! I enjoyed this "shop tip" video. Thanks!
Well said "how much precision do you need"
Thanks for sharing Keith,
Cheers
Seriously! Years ago I had a "Temp" gig at a plastics company. They did vacuum forming. Drawings had no tolerance specified which means +/- .001". They had two dial calipers. One had been dropped and the crystal was broken Shop Foreman asked me if I had broken it and I said: "I DON'T DROP TOOLS! It was like that when I picked it up!"
PITA job. I didn't EVEN offer to bring MY tools there because they didn't pay me enough!
I am a machinist as well but I'm always looking for new practical tips and tricks to help make my work easier and better.
I also enjoy seeing the old machines and trains that you deal with.
I'm retired now but I'm still very active, I wish I were closer to you because I'd love to get involved in some of the restorations!!!
I used to do a lot of videography in my spare time but now it's mostly just machine work and electronic control systems.
Anyway, I wouldn't say that calipers aren't as accurate as micrometers, it's just that micrometers offer a higher level of resolution since they have a vernier scale for 10ths.
I can often guess to within a 10th or 2 how many 10ths are involved by looking at how the needle is situated between the marks on a set of dial calipers and I'm certain that you can too.
I usually only get out my micrometers if I need to measure in 10ths or if the part is too large in diameter for calipers.
IMHO, viewers that harp about something like that MUST NOT do any machining themselves, otherwise they'd know how impractical and silly it would be to use micrometers for most everything. Again though, if a part is too large in diameter to use dial calipers, then the best choice is to use the appropriate sized micrometer even for low tolerances.
I have enjoyed watching your channel as well as Adam Booth's and Tom Lipton's :-D
Thanks, Keith!!
Joe
Thoughts are right on the 🕒 and 💰.
Keith, very well said. What are you measuring...that is the key. I wish that PBS would pick up your show like they did with Norm Abrams. Please continue to make videos.
To do a Norm-like show, Keith would have to learn how to slap the completed project and say "Perfect!"
I'm kinda thinking that if someone has a set of gauge pins, then they are already comfortable measuring with either tool. But, your point is to take a known item and practice measuring it. This is excellent advice. If you don't know what the exact measurement is, you can practice getting the same measurement over and over, but if you don't know what it's supposed to measure, you don't know if you are doing it right and maybe you cranked down too hard. This would actually build a bad habit and would cause troubles when building to spec. But if you are building a copy, your measuring tool doesn't even need to be calibrated.
Chocolate or vanilla.....its up to you. I agree with you Keith, calipers.
Well said, the same for analog meters VS digital meters in electrical measurements!
If I've been using the same dial caliper for any length and know the feel of them I've felt comfortable working to .0005'. I've seen a good saw man cut consistently within .005" using a tape measure. It's all about how much you trust yourself.
Good Job, Keith, Next one on Blueprint reading
Great video! I have only been working (playing) at this for a couple of years, so I am still a long way off of building precision parts. However, as a craftsman building all sorts of wooden/metal/pastic/stone/etc things over the years I can totally relate to your take. 95% of the stuff I build can be within 1/8"--1/4" . 4.9% of the time I need it down to a 32nd or 64th. And that last .1 % well lets just say I might bump or bend or tweak to get there. I can remember very few times in my life that things had to be ultra precise. Moral of the story, measure/build to the needs of the situation. Theres a big difference in framing a house and building a rocket ship.
Well said on your side Keith. In my defense, I guess too many decades making military spec parts and pharmaceutical parts has me doing all my precision measuring with a micrometer. I will add if anyone is going to use their calipers as their "go to" measuring tool, make sure you check out the jaws with a gage block to see if there is any wear towards the tips.
Jeff
It never hurts to refresh your memory on how to use a micrometer.
THANK YOU...for sharing. Hey, we are not making heart valves here. thank you for the refresher course. Enjoyed.
I had to read a far ways down the page before I found some guys commenting about checking their measurements while roughing out with calipers, then switching over to the micrometer for the fine measurements at the end.
It's as Keith says, the calipers are faster, and often good enough.
Another topic which I see is about why a micrometer is generally capable of finer readings than a dial caliper.
The way that I phrase that is that you can get more threads per inch on a screw than teeth per inch on a rack with a pinion gear, and you get a longer sliding distance by making the scale wrap around a spiral.
That said, vernier calipers don't have gears, and can be more accurate than dial calipers - at the cost of time spent reading them. But, the scale slides on a straight line, so you have practical limitations. The various scales used by digital calipers can have some advantages in readability over the vernier scale, at the cost of being a bit fussy about holding zero and eating battery charge... which doesn't always correlate to the purchase price or the name on the label...
It all depends, and personal preferences aside, what tolerances are good enough for any given job...
I used to work at an optical electronics operation as a very young engineer, and had designed some parts where thermal expansion had to open a very accurate gap of a couple of thousandths of an inch for the electrodes to function optimally. The gap was incredibly narrow, and given that the parts were welded into an assembly, the pre-sets had to be very carefully fabricated in order to minimize the infant mortality and trashing of the rather expensive materials that make even more expensive assemblies.
Since this was for a development project, my work got assigned to a drafter who came from a temp agency, and what little experience he had was with making mass produced parts.
You could hear my roar of anger over half of the second floor (or so I was told!) when I got the checkprint and found that he had taken it upon himself to "correct" my design tolerances for me, "because nobody can hold tolerances so tight" as he lectured the "impractical and inexperienced" junior engineer...
He was still very smug and self-satisfied when the drafting department manager and his deputy came by to see why I was going off... something about not asking me first about why I need the parts held to such tight tolerances, and then trying to lecture the engineer rather than discuss the design on a point-by-point basis to understand the reasoning behind *why* my parts were a bit exotic...
It only took about a minute for him to lose his self-satisfied mindset after these two worthies arrived...
At the other end of the spectrum I've designed equipment for bulk materials handling and industrial ventilation where +/- 1/8" (or more) is more than close enough...
Great work
Thank you for that I was wondering about the differences
Very helpful, thanks!
Thanks well put.
Agreed... serious issue... :)
I have a secure space for both tools - and they never get back there...
I really need to mount them somehow above my work bench...
Hint - metric micrometers are simpler :) but calipers are wonderful for fairly accurate reads.
Measure with a micrometer, mark with a crayon, cut with an axe.
The construction workers motto, "beat it to fit, paint it to match ".
Yep, if it doesn't fit , force it. If it breaks it was defective and you found out now, not down the road.
Use the four Fs. "File it, fit it, swear, file it again...."
LOL!
Great Video! The job dictates the tool needed.
Well said Mr. Rucker
The worst thing with calipers is that people tend to angle them instead of looking for the lowest measurement on O.D. or the highest on I.D. The other problem is not knowing if the inside and outside are reading the same (somebody dropped them). when sneaking up on a tolerance fit, the calipers are out.
"I don't like tomatoes." Well it's a good thing this is my salad and not yours. Ain't it?
Thanks! I'm not a machinist but have used both calipers and micrometers. The first thing I notice is how you keep the calipers in a box. That might be part of why yours are accurate even after heavy use. It might be time-wasting overkill, but I used to check both for zero reading when they are closed. What do you think? Many of the micrometers come with a little spanner wrench for zero setting.
I recently machined a spacer block / bracket. The only dimension I even measured was the hole spacing, and I did that with a ruler. I could have done it by marking the spacing on a piece of paper, and transfering that to the workpiece. Even dial calipers were overkill. The part worked and looked fine the first try. Don't buy a laser interferometer if the tolerances are +/- 1/4 inch (6 mm).
Mikes are great on some gear cutting ,but when measuring cut thin by on gears suggest you use a good vernier
You are THE MAN
well said, appreciate all your work bringing us great content.
It takes experience to understand the differences and it takes a demanding schedule to be discerning.
Spot on Keith 👍🇦🇺🚜
Thanks for the vid.
For 99% of most peoples shop work a good caliper is good enough. I usually only use micrometers on bearing fits.
cnc stuff is harder to measure accurately with just calipers, because the parts are more complicated. like a shallow face groove in a piece of stainless, if you try to use the calipers they will dig in and flex too much to get an accurate measurement, sometimes you just need other tools like an inside mic. Definitely for +/- 0.0005"
Given the nature of this channel (vintage machinery), and the fact that the tolerances used to build that machinery 80-100 years ago, I can understand Keith's point about dial calipers. If your building a nuclear reactor, get out the micrometer....
A dial caliper doesn't just do the same job as a micrometer, it does the same job as dozens of micrometers.
Good wrap-up! Lets not start a flame war!
Keith, please discuss accuracy versus precision.
steve
And clearances versus tolerances while you are at it...
I like the dial calipers too but the analog digital micrometer is my go to.
Never seen an Analog Digital anything.. is this some new technology?
@@steveredenbaugh9058 No. It is micrometer that has a window with digits that are visible. It is mechanical, and the numbers are printed on a wheel that turns and read through a window.
@@ianbutler1983 so it`s analog? can`t be Analog AND Digital.
Steve, I suppose a more accurate term would be mechanical digital micrometer. Here is a link to see one:
www.mscdirect.com/product/details/38173217
You are wise!
Do what is required for the job. For others to criticize when you are the one doing the work and the job works out; nothing else matters including the obsessive compulsive use of too accurate a measuring tool.
We used to say that the definition of an engineer is: calculate to a ten thousandth, Mark it with a piece of chalk, cut it off with an axe. Like you say, it depends
Thanks Keith, ... This is exactly how I think on the subject. Yes, tracking alignment with a dial is way better than digital. The dial paints a picture, digital is just a range of changing numbers, ..... good luck on that?
Just like many others I use both depending on the work and tolerances required. Is it great to turn a part to 1.25000 inches, yes. However if the spec sheet says 1.250 + - .005 is it really necessary?
Good example
Even the cheap electronic Chinese calipers for $10 can measure quite accurately - to 0.001 if you know how to measure. People get these, abuse them and then say they are crap. Once you realize that its all in the feel and pressure you apply you get good results. Also need to zero them often. Dial calipers are nice as well but more fragile - once you drop them on an end or front when open they are damaged. Micrometers are cool but very slow to measure and without much practice not much more accurate then caliper. Most work in hobby machine shop is not in need of accuracy beyond 0.001. Only reason to do such accurate work would be to have some fun trying to hit the number.
thAnks for sharing
I find there's enough space between thou divisions on dial calipers that I can do half or third thou accuracy with that tool
Sorry WD, but the mechanical design of dial calipers doesn't and won't allow that level of consistent repeatable accuracy. The industry standard for high quality measuring equipment is always a repeatability of + - one count of the tools resolution. Or + - one thou on .001" reading dial calipers. And what a tools dial or display shows isn't it's repeatable accuracy level. How many divisions or digits there are is called the tools resolution. It's repeatable accuracy and that resolution are not even close to being the same thing. My Mit digitals will display to 1/2 a thou I ignore that number since it's meaningless.You could build a large faced set of dial calipers using the same standard design and put 10ths divisions on it, the tools internal mechanical design still can't repeat or be any more accurate unless that mechanical design is changed to allow that level of accuracy. At one time I believe Starrett and maybe a few others did try making special 10ths reading calipers quite a few years ago. I recall reading they were selling for well over $3k, mikes are a lot cheaper and more durable so almost no one bought them. And a caliper can be that allowed + - one count out on accuracy and they will still pass through even Starrett's, Mitutoyo's, Mahr's etc QC checks. Mostly the equipment will or should do better than that. On average with anything I've checked against gauge blocks it's usually but not always about half of the allowed deviation.
A set of calipers has some small but very important clearances to allow the tools measurement assembly to even move. Those non optional clearances allow the moving jaw to very very slightly rock out of squareness with the fixed jaw no matter how well there made or by who. For the best and most accurate technique Mitutoyo states that the thumb wheel isn't used. Your supposed to gently squeeze the moving jaw and fixed jaw between your thumb and fore finger for smaller diameters and use both hands to do the same on larger parts. And using a consistent closing pressure every time is important. For round parts that closing pressure should be centered on the calipers jaws where they touch the diameters C/L. It's within feasibility one single measurement just might be able to be read to that half or third of a thou and even be correct. And the next 5 or 100 measurements might be well off that. That's the problem with them, you just don't know when there out to more than that half / third of a thou or by how much. I've checked myself and my calipers more than enough under ideal conditions on very good gauge blocks using the best techniques I know of, and calipers can not be depended on to that level of accuracy. There design makes doing so mechanically impossible. They simply can't repeat well enough to where I'd ever bet real money on even which exact thou there reading to never mind half or thirds of a thou. My solar powered Mits are the tightest yet smoothest pair of calipers as well as repeating to the best level I've seen so far. They'll beat either of my 6" or 12" Mit. dial calipers easily for there repeatable accuracy. They can almost always repeat to about a thou and sometimes less on those gauge blocks under those ideal conditions if I do my part. But if it has to be within .003" or less I always use a mike. Many might chose to disbelieve some or all of the above. You sure don't need to take my word for this, no ones stopping anyone from doing there own research about it. There's lots of free information on metrology manufacturers websites that will back up anything I've said.
@@turningpoint6643 Thanks for your treatise. You've used a large number of words to tell me I cannot do something that I know I can do.
Give me two well made standards,, one at 0.5000 and the other at 0.5005 and my Mitutoyo calipers will pick up their difference easily.
@@wdhewson Great response, but it doesn't matter if you can tell the difference between half thou jo blocks. The tolerance dictates the tool. And I'm certain you wouldn't measure a .3937" +.0008/-0 dimension with a caliper, regardless of how nice or reliable you find them. It would be like slot milling with a cut tap...yes it CAN be done, but it's not good machining practice.
It does depend on the caliper, on some of mine they have 200thou per rotation dials, those are not so easy to get consistent below 1 thou but my 100thou one 1/2 is easy.Ive never needed to go below that and thats only one specific job that i repeat often,more than enough to know that A i am getting consistent output and b:its showing in the data garnered.Im only talking about quality tools,no chineesium.