Dial bore gauge VS Telescopic gauge - How to use and calibration. Measuring a cylinder
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- Опубліковано 21 сер 2024
- Dial bore gauge, what are they and how do they work, in this video we'll see how to calibrate them and how to measure using them. The main use is in measuring a cylinder or a bore. measuring out of round, measuring taper or irregularities in a cylinder or any bore.
There will be a comparison with the measures taken with a three points micrometer and a direct comparison with a telescopic gauge.
As a very important part of measuring with high precision in a small machine shop or in a hobby situation, I'll talk about some precautions for proper handling in order to get the best possible results.
By using a cylinder bored with a special preparation we'll also be able to see how we find out defects in machined parts.
Thank you for viewing
Please feel free to comment, like and subscribe... ;)
Pierre Beaudry
Email: wledpierre@gmail.com
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Very clear, easy to understand explanations ! And thanks for bringing in the human side, as well :)
Glad you liked and thanks for taking a moment to leave a nice comment 🌈👍
Towards the last you demonstrated exactly the lesson I taight apprentices that came under my thumb. Don't look at the mike when taking readings. You can easily fudge a thousandth (or two, if the mike is large) without knowing it. Same goes with any direct measurement tool depending of feel. DAMHIKT.
Story: I was called in as a third party settle a dispute in miking a 20+ inch bearing fit on a very large part. The tolerance was 0.0003 to 0.0005" interferance with the inner race of a high precision bearing whose net bore was known to 10 millionths. Ten thousandths readings on a 20 inch feature is 6 significant figure accuracy - something best performed in a temperature controlled lab not in the open shop. One degree F difference between reference and work to be measured is 1/3 of the tolerance. Calibrated thermometers taped to work and stack agreed to one degree F. The mike was old but in good shape. The calibrated accuracy of the mike was not an issue because it was used as a comparator. There was a stack of gage blocks handy to reference readings. I recall checking the blocks in the stack against their calibration sheet and summed the listed error with the nominal stack length - about 11 millionths as I recall, not enough to consider in the readings to be taken but a step to further validate our procedure.
We all measured again going back and forth from work to stack taking several readings each and listing them, taking such care to not look at the thimble we draped a dry shop towel to block the view. After tossing out a couple highs and lows we settled on an average reading about a tenth under the high side of the tolerance. Measurement by committee and statistics to be sure but those taking the readings were skilled, practiced, and experienced. Whatever our method, I'd argue a metrology lab couldn't improve on the accuracy of our final reading except by adding a significant digit.
This is an extreme example never to be seen in the home shop but it illustrates what may be accomplished with simple tooling when accurate references are on hand simply by eliminating and/or accounting for soruces of error.
This case is something you only face in very high precision machining, I mean HIGH precision, mostly in those larger diameters...
This is where your body heat radiated to the measuring area will have a measurable effect... Just like you did, by referencing and averaging and re-doing the procedure until you got a reliable and mostly repeatable readings, you finally got close enough to be certain the part was accurate, this is an ultimate challenge...
Not for the clumsy numbed fingers...
Thanks for sharing your interesting and mainly extreme situation, Pierre
Love it when I open a video to learn something & I'm not greeted by a teenager..
Lol... !!!
Thanks for your comment, but, some days, when my bones hurt, I wish I was one, a teenager.... 😱😁👍
Very informative and interesting video thank you
thank you for your comment.... 🙂🙂
I liked your series in internal measuring tools. Thanks for sharing 👍
+Asaad omar Hi, I'm glad you like and thank you for taking the time to mention it, Pierre
Great video! Those 3 point micrometers are so expensive! Compared to telescopic gauge and bore gauge!
Thanks for your comment...
Right about the price of those 3 points micrometers, the amount you're ready to spend is dependent of the type of results required to achieve, for a hobbyist, an amateur or even a small general works jobs a good set of of snap gauges will be a reasonably affordable solution giving very decent results, as with any high precision work you also need some good practice in the feel in order to get repeatable and accurate measurements. 🙂🙂👍👍
always learning, always learning.
Nicely done Pierre, Loved the joke, Harold will have some competition.
+Phil's Projects Hi Philippe, I'll never look as funny as Harold does....... lol
Cheers Pierre
I know this is an old post but many will see it. When I have a critical dimension like that I usually stop right before the dimension and do a Spring pass. Meaning I don't make any changes but I send the tooling through the board or the outer diameter at the same dimension that I previously set to to even things up. I will do this 1 or 2 times depending on how close I am and how important The boar where outer diameter is.
There is a way to calibrate your passes in order to avoid having to make spring passes, in a few of my other videos I demonstrate how to achieve it on the lathe, in short, it's by making a few equal passes and calibrating the real removal of the tools taking into account the deflection, once you're calibrated you just need to continue making equal passes, there the dial or DRO will yeld the exact measurement of where you're at. Normally you could get there with two to three passes to do, this normally gets you within +/- three thents of an inch. Just make sure your part isn't hot when performing any precision machining, or compensate for retraction due to cooling of metal...
Another interesting tool and great tutorial on how to use it. Thanks
+MrPragmaticLee Hi Lee,
The first thing we learn in machininh school is how to measure and calculate things...
Cheers Pierre
Thank you Pierre, your video was a big help.I liked your point about practice and getting the 'feel' for measuring.
Practice and expereince are the KEYs to get better in everything you undergo in your life...
Keep on the great attitude and thanks for a nice comment, Pierre
How funny! I just started researching bore gages and wanted to see the difference between the two types. And up pops your channel on the first UA-cam search. Just ordered the T gages.... Thanks!
You'll quickly get used to measuring accurately with those, just get good quality ones, though...
Cheers, Pierre
Nicely put together. The micrometer stand looks handy when trying to get a consistent reading to tenths. I think I will keep an eye open for a used one. Thanks for uploading and keep them coming. All the best Mat
Hi Mat,
Those stands aren't that costly and really practical when you need more hands... ;)
Thanks for for a kind comment, Pierre
Pierre's Garage Hello Pierre! Where did you got these micrometers clamps?
You'll find them in the Mitutoyo's catalog under that series:
Mitutoyo stands- Series 156
I don't remember the price but it wasn't that bad, you could even for some second hand if you're lucky...
Thanks for comment, Pierre
That was very precise. You have some nice measuring tools. Liked the joke.
This has been a nice series on hole measuring. When you get down to the very fine measurements like sub .001" the surface finish plays a big factor in the size you measure. For lathe work the .0001" measures will likely vary around the bore because of the path left by the tool.
Hi Brian,
There are always little defects in a bore unless you have every condition perfectly aligned in a perfect world, normally with a good set-up the imperfections aren't so bad that a little lapping can't fix, this is where better and heavier machines have a definite advantage cause they produce better finishes...
Not every shop will produce parts under a thousand tolerance every time...
Cheers, Pierre
Great video Pierre! enjoyed again,ATB, Robin
Hi Robin,
Always a pleasure to have you visit... ;)
Cheers, Pierre
Such a good video. I'm new to this and this helped a lot. Thank you Pierre.
Hi Mark,
The goal of making these videos is that someone is learning from it, your comment is really pleasing, I'm so glad you got something from this, also, that you take a moment to tell me so...
Thanks and all the best, Pierre
That's another very nice measuring option Pierre... bit fiddly but sure has it's place. You sure have some real nice measuring equipment.
I think my old telescope gauges will have to suffice!
I shall have to rename you Mr tenth of a tenth! :-)
This demo was most illuminating.
Hi Chris,
With years, the collection of tools increases, the bank account decreases..... !!!!
The concept of communicating vases...... lol
Keep your telescoping gauges near they're also a powerful tool in the right hands...
My last nightmare was about "Microns" the metric version of tenths of tenths.......... ;)
Cheers, Pierre
Very few people use microns(1/1000) in common machine shop(thats more like super special NASA equipment type of shit ).Commonly used measure is 1/100(ball bearings ,shafts and things like that) of a mm. See how everything is nice and related in metric?You just add or remove zero.
:) Thanks for the video and the giggle
Thanks for viewing and taking some time to leave a nice comment, Pierre
i thought i new how to use it but iwas wrong but now i know how to use it=Thanks!!
Thanks for viewing and leaving a comment, Pierre
@@pierresgarage2687 thank you!!
I have been looking at measuring holes and I'm new to machining....dial bore gauges out of my budget...good telescoping gauges in my country about 300 dollars....so instead I bought 75 mm Starret tubular callipers ...new old stock...so they will be used like telescoping gauges....even if I have to blue the inside of the bore to get a witness mark and then measure with a micrometer.
I figure this is how it was once done before the advent of 3 point or dial gauges and of course one day I might be in a position to upgrade to quality instruments....at the moment tho I will try this method.
Cheers.
Hi Mike,
Just curious about what part of the world you're from...
I'm confused about the Starrett tubular calipers, could you give me another description...? I probably call that tools another name over here.
Pierre
Hi Pierre,
I'm in Australia...so our exchange rate is 75 cents to US dollar...plus anything good always attracts an extra premium out here.
These are the ones I got....www.starrett.com/metrology/product-detail?k=274-3
www.starrett.com/metrology/product-detail/Calipers-and-Dividers/Calipers,-Dividers-and-Tram/Precision-Hand-Tools/Precision-Measuring-Tools/275-3
I just received them in the mail...as new condition, played with them and feel confident they are an accurate enough way of measuring, spring is tight, nut is tight....no deflection because its minimized by the tubular construction, you can work the nut so tho calipers adjust very finely and they are small...tho easily extend to a 75 mm opening.
Cost me $90 AU dollars plus postage...would probably be $ 250 new from a tool store.
I think the calipers would be good for measuring groove depths also...very fine points but not sharpened...they move with just an amount of very small rubbing which would be on at least the same par as Telescopic gauges, as you said in your vid Pierre practise getting your feel....it will be the same for calipers...but so far it seems easy to get a feel.
Also my plan is to use the outside calipers as a rough guide when turning outside diameters....set the calipers just slightly bigger than the size you need...you can refer to the calipers often rather than reading a micrometer all the time...when close to desired diameter switch to micrometers for the last couple of cuts.
I plan on getting the next size up down the track.
As I said an economical alternative as long as you purchase good quality.
Would love to see a comparison.
Here is the place I got them from....not far from me.
Cheers.
Starret model numbers if you can't get the site.
274-3
275-3
Cheers
I see, I wasn't thinking about that tool anymore. That was one of the method used before along with inside rod type inside mikes...
The caliper type you got, I've never tried it, not sure about making a video very soon but it would be interesting to try and se what kinda results I would get using those... ;)
Hi Pierre,
The Starret spring calipers I got today I have been using and quite pleased so far....can actually feel through the caliper the unevenness and machine marks in the bore...they seem to give good feed back and not difficult to get a measurement off my Mitutoya digital calipers across the Starret spring calipers...I think a good addition to any tool box...tho would be reluctant to purchase chinesium or friction calipers...needs a screw and spring and robust frame.
I'm sure for many years these spring calipers have been used by our forefathers for accurate measuring and just another option...an economical option I think, keeping an open mind and seeing what worked in an age before our fancy but nice digital instuments,
Cheers.
Very informative sir thank you 🙂
Thank you very much for the nice comment..... 🙂
LOL! And I've made several cone shaped bores;-)
We all make some cones in out times... ;)
Thanks for visit, Pierre
Great video and excellent explanation including the joke
Glad you viewed, liked and that you took a moment to leave a comment... 🙂👍
7:11 Rather then setting dial at exact zero before checking its micrometer reading I find it much easier to set it just slightly above zero and check with micrometer then. This way you know if micrometer is definitely in contact with dial and don't need to sort of guess if it is in contact already or not..
I'll think about you just mentionned when I need to use the gauge next time, thanks for sharing your expereince, Pierre
Can you use digital verniers that measure .0001 to measure with telescopic guages? The micrometer and digital verniers measuring do the same thing?
You can use just about any measuring instrument to take some measures or serve as reference, it all depends on the level of precision your job requires, as a digital caliper is precise within at best around plus or minus one thousand of an inch, as on the other hand, a decent micrometer will be precise about 10 times better, like I've said before it all has to do with your available resources and the requirement of the job you need to achieve.
So useful thanks
Glad all that work putting up videos, though, not perfect, can help people better understand some points in metrology...
Even happier that you took a few moments to leave a comment saying you appreciated, thanks, Pierre
How to set up the 2” EXTENSION?
i think i'm going to stick to my mic and my telescoping gauge. i came for dial bore gauges to see if i should buy one, and there are too many extra steps unless you plan on making 100+ holes that are relatively close to the same size.
The bore gauge is advantageous to monitor many areas of the bore in the cylinder, like roundness, taper, etc, as a telescopic gauge you need to take many measurements and it get more difficult in deeper bores... Guess it's a question of choice...
A good place to look for a new used unit is in the local adds, just don't be in a rush and you'll cross a good deal... This is how I got some of my tools... ;)
@@pierresgarage2687 what i do doesn't require too much precision. Around 5thou plus or minus.
Guess the telescopic gauge could be a alternative, you just set it to what you need and poke around inside the bore, this is only good for broad tolerances, though...
Pierre, do you think that this dial bore gauge from Mitutoyo is more precise than the dial bore gauge from Fowler which has wheels and less degrees of freedom?
Hi, making real fine and precise measurements is 95% finesse and handling, more than the actual instrument, as long as the instrument isn't defective, though. You need to get some practice and compare yourself with something accurate whenever possible.
Thanks for stopping by, Pierre
When you make a cut inside of a bore you double the measurement correct? If you set your cutter @ .010 you will actually cut .020 correct?
It depends if your cross slide, carriage dial are indicated in function of the radius or in function of the diameter, it's easy to check, you make a cut taking for an example 0.010" and if you actualy measure 0.010" your dial is set for diameter cuts, it means that the carriage actualy advanced 0.005", on the other hand, if you make a 0.010" cut and actually measure 0.020" it means that your dial is set to measure radius...
Also look for the slashed 0 symbol on the dial, if present it means that your set in diameter.
Be aware that croos slide is often set to diameter and compound is most likely set to radius or actual movement...
Hope I was able to make this clear to you and this was what you needed to be clarifief... ;)
Thanks for viewing and for your comment, Pierre
I don't like set up bore gauge with micrometer. For the stress to the spindle first, secondly the difference between micrometer (Mitutoyo) and Jo blocks stacked at the same dimension is always half a thousands undersized. 2 tenth.
Like you mention, transposing measurements is introducing an error, even minimal, that accumulate as we add steps, This is where expereince and judgment come in to reduce risks of errors...
Thanks for your input, Pierre
Big salutation from Italy.
+Magic Rojava Here it's icy Montreal, CANADA....👙😊
+Magic Rojava Here it's icy Montreal, CANADA....👙😊
Sorry Pierre... I have an amletyc question... I'm not able to speak fluently english so maybe it will be hard.
The big question is: why we have to measure the telescopic gage touching, "feeling" the face of the spindle? Why don't use the ratchet?
For example: in one hand we have a 1" setting rod for mike, in the other one we have a telescopic gage and we've just measured a perfect 1" hole. Teorically both have exactly the same lenght, have not them?
With the 1" rod, when you set the mike you use the ratched (that tightens strong enough the rod), so why don't do the same with telescopic gage? But yet the difference between using the ratchet - and so tightening an object - or not using it, and so "feeling" the faces is about half a thau in my little experience. 4-5 tenth.
I'm practicing with some different master rings with few millionth calibration (fraction of micron or hundreds of nanometer), and honestly, in my case, I have the correct measurement if I use the ratchet. But watching all you great youtubers and machinists, no one of you use the ratchet and wish I understand why.
Hope I explain myself properly!
Can a dial bore gauge be used like a 'long reach' dial indicator, to show variation in deep holes? I'm picturing a holder for lathe toolpost, just cranking it in by hand and maybe rotating the part to check for shape or runout. Just relative change, not actually needing to measure a solid number.
Hi, in my opinion, the holder wouldn't be accurate enough to self-adjust to the tenth of thousand of an inch, this is very touchy, this is where the human touch wins over machine... ;)
You would need to conceive another type of device better adapted to your idea...
Thanks for your input, Pierre
How do you do such things? For holes deeper than a couple inches I don't think I could use a telescoping / snap gauge, can't swing the handle far enough.
For example, measuring an R8 spindle bore in front and back. (I just bought a milling machine project, so it's on my mind). Since the back isn't a taper I'm uncertain how much I could decide about what's going on back there from bluing up a known good male R8 shank.
Surely it isn't that unusual to want some measurements in a deeper bore, that something needs to be invented to do it! :)
Maybe a long shaft near the bore size you're measuring, with a perpendicular thread, you use a domed screw or pin, insert and adjust until you get a snug fit, you measure the max deflexion. Make certain everything is parallel and straight... This could be considered a poor man's bore measuring tool....
how about the plug gage test? turn a bar to 1.3391, as measured by external mic, and tell us how it fits?
That's an idea, I'll have to find a moment to make that slug and do a test, you need a couple of thousand under or it runs the risk of not fitting... even little interference from irregularities will stop it from entering...
Thanks for your suggestion and for comment, Pierre
yes. emphasis is on the whole process. material selection (will it work with an aluminium piece), time to completion (how fast it can be done), repeatability, to name a few.
if i get high quality bore gage can I expect that anvils and washers are so accurately manufactured, that I wouldnt need a micrometer?
I wouldn't trust using a dial bore indicator without a good reference to an accurate micrometer, I suggest you keep your eyes open for a good used micrometer, it usually comes quite at a reasonable price for a brand name, or, look for new ones from Fowler, Shars or some other decent tools.
Thanks for viewing and for comment, Pierre
that was good
Hi Jim,
Thank you for viewing and for comment, Pierre
hello Pierre, I really learn how to measure with the Dial bore gauge, the reason that I search this video is to rebuild my Subaru legacy 03 engine that's my project, by the way, I'd like to know the model that you have or any advice in order to buy one, best regards from Inca's Land
(PERU)
The tools I own, they are Mitutoyo series,
For measures from 0.7" to 1.4" : 511-104
For measures from 1.4" to 2.5" : 511-105
For measures from 2.0" to 6.0" : 511-107
The dial indicator number is: 2923S-10 or a 2923F-10 either one will work, I have both.
Cheaper stuff is almost never an investment... Sometimes you may get decent cheap tools, but, it's not to be relied on unless you got reliable referal. If you only want brand new tools, you may want to look into brands like Fowler, Brown & Sharp, InSize, SPI, Mitutoyo, Starrett, agreed that some of those are in the $1000 range. On the other hand, if you could consider good condition used tools, you may get very decent brand name at great prices, some of my tools are in that category, I'm real satisfied with those. BTW, I got a cheap one once and it went in the scrap bin, it was a useless tool...
As for telescopic gauges, same applied, remember having to work with a cheap set once, it was quite unreliable, mostly using the smaller diameter ones, the problem was the spherical ends weren't rounded enough to not hell on the surface on retraction, took me a while to figure this one out, same advice with those, get good ones. Any real cheap tool you could consider, just try to get references from a reliable source before considering the purchase, in the rock bottom price range the gold nuggets are quite the exceptions...
Hope this helps, All the best, Pierre
Pierre's Garage thanks for taking the time to answer me , keep doing best videos on your channel, best regards, Steve.
9:34 I know you subtracted .0086... but on the tape you wrote - .0006
cetais beau , moi je prend les snap gauge et apres le mic, ton bore gauge the first one confused me cause i did not know how to read IT ? nice vid informative , salut
Allo Denis,
Snap gauges are ok for bores that aren't so deep, dial bore gauge will be faster if you need to test the cylinder at different depth and at many spots since you don't need to pull it out every time... It also depends on how often you need it... ;)
We're coming out of the big snow storm, there was a lot of it ,it's been a while since we got so much.....
Cheers, Pierre
yes for me its only cylinder bores for vw my hobby they are not too too deep , as long as i can determine that the cylinder is not out of round or is ? its ok with me its done its job ,,,,merci , vien pas en floride ce matin cetais 34 ici a Inverness fl tonight will also be cold , its usually like that at this time our end of winter two days LOL . cest moin pire qua joliette jai ete souper sur un de mes amis qui a une camera qui peut voire ca maison et cest plein de neige comme ils dis on ne sen va pas avant la fin d'avril LOL . salut thanks
Si tu veux voir de la neige, regarde la video d'hier soir... ;)
J'ai pas mal hâte que ça parte.... Beuark la neige... lol
I see numbers every 5 on my dial bore goes up to 25 halfway then number decrease the full 360. How do i read those numbers if the bore gauage moves to say 5? Measuring something 5.0000 is it 5.0005
I can't see how your dial works, and what units, you could send me a picture on my private mail, then, possibly I could see the dial and help you...
wledpierre@gmail.com
@@pierresgarage2687 thx i was able to figure it out took me awhile... each hash is .0005. Have another question is a micrometer better vs a caliper wiyh verniers on it? Using both i get two different numbers off by 1 thousands. Im measuring the skirt on a piston. My spec sheet on my pistons match my calipers but micrometer does not even after a calibration.
Hi
Sorry, but what does the little dial on the dial bor that goes from 0 to 5 do
+Zephyr Old This dial tells the total deflexion from the reference you set at the start, thoa dial is set at zero and wjen you measure depending if it's plus or minus you'll see the needle going plus or minus, then you can tell how far from reference you are....
Thanks for comment amd I hope the awnser was clear enough, Pierre
Thanks for your answer, loud and clear
You would never want to turn the bezzel to the needle you want the needle to be as close to the zero then twist the dial to zero so you are not turning your head. Also the lotto dial you want at zero not at 4 cuz if it is not at zero then your measurement will not be right it will be thousandths off. Use a ring game it will be a lot easier than a mic
With that rust ?
How u set up make video
Can you tell me the model number on your gauge set pleez i want to order that one
No problem, they are Mitutoyo series,
For measures from 0.7" to 1.4" : 511-104
For measures from 1.4" to 2.5" : 511-105
For measures from 2.0" to 6.0" : 511-107
The dial indicator number is: 2923S-10 or a 2923F-10 either one will work, I have both.
Hope it helps, Pierre
What is the tiny dial that goes from 0 to 5?
This dial has a range of 0.050", every complete revolution of the dal is 0.010", so evert time there is one revolution the tiny dial will indicate the number of revolutions...
As an example if you measure, 0.0243" the little dial will indicate 2 meaning you have 2 revolutions plus 4.3 thousands on an inch...
Hope it's clear for you to get the principle, if you ned more explaining don't hesitate to ask...
Thanks for your comment, Pierre
Thank you, so it reads hundredths of tenths, right?
This is a thousands of inches: 0.001" Metric: 0.0254mm
And this is a ten thousandth of an inch: 0.0001" Metric: 0.00254mm just like in this type of indicator,
isn't that 1. 3 thousand 3hundred and 91 10,000 ths
for any amateur's watching, this is a parody. Not even close to how you set up and use a bore gage.
This way works for me and some other machinists, if you know some different and better better ways, I'd be more than happy to learn, please share... 🙂
half a tenth more than likely acceptable? You ought to be ashamed of yourself. Aim for no less accurate of 1 ten millionth of an inch