Using Verniers as Verniers, and to make a lathe 5 times more accurate...
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- เผยแพร่เมื่อ 28 ส.ค. 2024
- Most people don't know a Vernier can be used in four different ways, internal, external, depth and step. This video explains the fundamentals of the Vernier scale, how to use a Vernier and how Verniers can be used as digital readouts. The Vernier scale can also be used to improve the accuracy of a lathe by as much as 5 times.
Check out www.adendorff.... for there wide range of Verniers...
Canadian here. We would cal it a caliper. A caliper with a Vernier scale is a Vernier Caliper whereas one with a digital readout is a digital caliper. Vernier scales are definitely very clever.
Hi John, thanks, that is probably more correct... In SA, we generally just call them verniers, and a caliper is what we use to transfer internal or external measurements, very old school! Thanks for watching!
Hi Luker,
I would be interested to see how you go about accurately scribing the outer half of your lathe dials; tool(s) used, method, etc.
I know how I would try & likely muck it up, curious if method, tool or skill is the problem.
Hey mate, good on you for taking the trouble to make this video - very informative. Utilizing the piece of stock when measuring the drilled hole to keep the callipers perpendicular and then subtracting its thickness was a new tip for me. Appreciated.
Thanks! It's from a series of training videos I've been asked to put together, as I do them, I'll dump them on my channel. Glad you liked the tip, that zero button gets abused! Been keeping an eye out for your Virginia build...
I would recommend store your vernier back into its box with the battery out (in the same box)@3:06.
A digital vernier is the same as a digital caliper. If you don’t know how to use a caliper and you wouldn’t mark and use your dial; you better go with a DRO (same as a digital caliper or vernier).
@4:15 you could first measure the “bar stock” or gauge block or parallel and zero the vernier. Then measure the hole.
There are cheaper DRO scales cheaper than other verniers with the same quality. Those scales are designed to not use energy while turned off as supposed the cheap verniers that devour batteries. @6:26
I used to mark my machines (when DROs where super expensive; i know, i’m almost senior citizen) starting with the first and last limes (since you can rotate it as needed) and make 10 divisions 1/9th of the scale in other words i made that 10 divisions in fit 9 divisions of the dial (there were metric and imperial machines at my job). It’s always a pain adjusting your lead screws to zero backslash, but it’s needed.
Using a Vernier to improve lathe accuracy... Clever...😊
Accurate to 10 microns or .00039" ? As others have pointed out, there's vernier, dial and digital calipers, and afaik no company makes any dial or digital caliper with a vernier scale on them since it would be unnecessary. But you might be confusing or mixing up your Digital Calipers resolution verses there real world accuracy. Resolution is simply how many digits that are displayed to the right of the decimal point and are in no way any guaranteed level of the tools actual degree of accuracy. Secondly the universally accepted metrology standard used world wide is a measuring tool should have a repeatability and accuracy level of within + - one resolution digit to then pass the manufacturer's own internal quality control checks. And most of the better metrolgy equipment will always come with specifications within the user paper work for that specific tools resolution and guaranteed repeatability, accuracy. Too many refuse to even read or fully understand what those terms mean. As an example, a .001" resolution micrometer could have a maximum deviation of up to .002" of the true measurement while still passing those quality control checks. There's also a term used in metrology called uncertainty of measurement. It's also commonly accepted industrial practice that any measurement tool needs to be at least one order of magnitude better than your required level of accuracy for measurement to remove that uncertainty. I've checked most of my Mitutoyo and Starrett measuring equipment against an almost new condition set of Mitutoyo grade 2 gauge blocks. Most of what I do have does fall within about half of that allowable + - inaccuracy deviation.
I've also taken the time to check both myself and my measurement techniques against those same gauge blocks. Under ideal, spotlessly clean and temperature stable conditions, my Mitutoyo digital calipers will average within about .001" of true measurement on randomly selected gauge blocks and the marked sizes facing away from me. At random times they will in fact show the correct size. However there's no way to be sure when or even if that might happen.Those measurement checks are of course done under the best conditions I can manage in my own shop. Measuring parts still in a lathe chuck or mill vise, then I'd only trust my own measurements with my own calipers to be somewhere within .005". Yes the actual measurement should be better than that by a bit. But if I need to be certain to less than that, then a vernier, dial or digital caliper isn't the tool you should be using. There's also an extremely common mistake made with calipers and using the thumb wheel to close the sliding jaw. Mitutoyo has an older video somewhere here on TH-cam pointing out that thumb wheel is only for coarse movements. And for smaller sizes, the caliper should be closed by gently squeezing the jaws over the part using your thumb and fore finger. And those should be placed in the rough center of each jaw. And that's especially so when measuring round shafts since that puts the closing pressure (or should) centered on the part your measuring. For larger measurements, the jaws should be closed on the part to be measured using both hands. I can say that is a slightly more repeatable and accurate method over using the thumb wheel. My digital calipers do have a .0005" digit, in reality I simply ignore it since the tool simply can't deliver that accuracy except randomly despite what it's resolution might be. On a good day I'd suggest your probably accurate to within about 70-80 microns, or .003".
HI Pete, you’ve raised a number of points and unfortunately I might not be able to give an adequate response in a TH-cam comment; when I was lecturing design and manufacturing techniques, subject matter like tolerance, machine accuracy, measurement tolerance etc. used to take up a number of classes (with some interesting maths and statistics), but I will try my best. Accuracy in measurement, like average in statistics, is ambiguous. Accuracy in the context of my home workshop is to have the ability to machine within 10um (between components) and sometimes less when and if required. Because completed assemblies are measured using the same machines and measurement tools the measured differential accuracy is well within 10um. This is not to be confused with a specific measurement to within 10um at the standard temperature in a controlled instrument room. As long as the components I make don’t go to another assembly point or are not measured using instrumentation calibrated differently, the accuracy is defined by the deviation from my tooling and measurement apparatus, which will be a very small deviation. In the real world you are of course correct about the resolution especially in industry, however in a home workshop where relative fitment is key, resolution and measurement accuracy is the same. This is all very theoretical and we need to be careful not to confuse industrial measurement norms and home workshop measurements. Regardless the proof should always be in the pudding! One of the most difficult items to make in model engineering is a steam injector. I have made all the injectors for my loco’s including a number of 8oz injectors. Most of my locos have two injectors one for high and one for low pressure. If you are familiar with what’s involved with making these devises then you’ll agree the accuracy to make the tooling and cones is below 10um and the fact that I have yet to scrap one, repeatability seems to be good! I appreciate you taking the time to write such an in-depth comment, much appreciated! PS: In SA, we generally just call verier calipers, verniers, and a caliper is what we use to transfer internal or external measurements, very old school! Thanks for watching!
@@Lukers_tinkering Yes I appreciate what your saying and I am at least a bit familiar with the requirements of building injectors that do work. So far I've not built one myself though. And for what were doing, properly fitting the parts for the expected function is more important than there exact NIST level size. Fitting commercial bearings might be the exception to that for most of us.
But!!!! your statement of being within 10 microns using digital calipers is misleading to the more entry level people since there incapable of ever making repeatable measurements at that level. And no, resolution is most definitely not the same as accuracy, neither Starrett, Mitutoyo or Mahr would ever agree with that statement. I'm not being argumentative, I'm simply trying to be factual. You could put a 1/millionths display on digital calipers, yet the tool itself can at best have an accuracy due to there design of roughly + - .001". So the design and gauging method any caliper uses physically prevents that. I could easily make repeatable measurements within your 10 microns using my Mitutoyo digital mikes or even comparison and transfer measurements using my gauge blocks and a Mahr millmess indicator. But as good as I think my Mit,. digital calipers are, I've proven the company guarantees within the user paperwork of what there capable of are the limits, and even then only under the best possible conditions and using careful technique as well as observing a repeatable closing force on the moving jaw. Correct measurements at random times are meaningless since there's no way to tell which random measurement is correct when or if it were to happen.
Under normal shop measurement conditions, I'd say my calipers are probably approaching at least double the inaccuracy I see against gauge block measurements. As I said, mine have a .0005" digit, even if they were absolutely 100% repeatable which there certainly not to .0005" levels, then at best due to the internal circuitry and the way they round off that last digit, the measurement would still either be true if the part was in fact at that dimension, or somewhere within a - .0003" + .0002"" range on either side of that last digit. My digital micrometers are good to 50 millionths", and it's more than easy to still be .0001" off on gauge blocks that are guaranteed to be within 4 - 6 millionths of there true size.
I have run across a very few mentions of Starrett and possibly Mahr offering .0001" capable digital calipers roughly 2 -3 decades ago. There's almost no real information about there design or any pictures I've ever managed to find. One statement I find mentioned Starret was pricing there's at the time over $6,000.00. So far I've been unable to verify that anywhere else. Since 10ths capable micrometers are commonly available at a fraction of that price, the idea was probably a very quick failure. But the design would obviously be quite different than our commonly available calipers were using today.
Hi Pete, unfortunately I can see my answer was not understood, and for that I apologise. Some of my students battled with these concepts even with the maths and definitions before them. For example resolution and accuracy are different when you a measuring to a specific dimensional value and tolerance, but they are the same when you are only measuring to the tolerance. I.e. you not concerned with the actual value measured. Then repeatability becomes important, especially in model engineering to make sure the components will fit correctly. Have a look at the builds I’ve designed (you should find the videos by searching for Stirling, Ballaarat, Wahya, Fire Queen). With the knowledge that I did not buy a single model engineering item from trade, and other than the metric fasteners everything was made in my home workshop, ask yourself if all these components could be built without the accuracy I have mentioned. The simple answer is no. Unfortunately, unless you have designed and made injectors the engineering requirements may not be apparent. For the record I don’t agree with your statement that beginners could not make repeatable measurements at this level. Any beginner can machine to an accuracy far greater than I achieve, can cast components, make anything! Provided they take time to understand the required knowledge and practice. The simple fact is, as a beginner, I can do what I do because I refute anyone that says something cannot be done, I just do it!@@Pete-xe3il
Adding a super accurate digital scale on a Vevor table on an old drill press does not make it a jig borer.
Adding a model engineer to the old drill press might 😅@@tates11
The moment you realize the value of a digital caliper.
Your digital "vernier" is not a vernier. It's just a digital caliper. The dial versions are analog calipers. You need a vernier scale to call the tool "vernier-whatever".
In SA, we generally just call them verniers, and a caliper is what we use to transfer internal or external measurements, very old school! Thanks for watching!
@@Lukers_tinkering That's interesting. I've heard a few old timers just call them verniers as well. We also call the manual transfer tool a caliper.
@@sccolbert A very similar thing exists with vacuum cleaners being generally called a hoover.
In fairness to Lukers his video is mostly about use of the genuine Vernier scale for subdividing the larger indices on the handwheel dials. He only briefly covers the use of a digital caliper as a miniature DRO for the lathe.
@@howardosborne8647 That's a British thing thru and thru. No one in America calls them a Hoover. It's all Vacuum Cleaners over here LOL!
Another popular use for a modified digital caliper is to get a digital readout for the tailstock quill.
That's a good one! I'll remember that. Easy enough to make a simple clamp... thanks for the tip.
I'm otherwise enjoying your video but why are you calling your calipers "verniers"? That's really unhelpful terminology. You end up calling a digital caliper a vernier--it doesn't even have a vernier scale. Makes zero sense...
Hi Steve, thanks, that is probably more correct... In SA, we generally just call them verniers, and a caliper is what we use to transfer internal or external measurements, very old school! Thanks for watching!