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View Full Version : Digital vs. Dial Calipers



garagemark
04-07-2011, 07:52 PM
At the risk of hijacking another current thread, what is the draw to digital calipers? I have three calipers, two 6" Mitutoyo's and an 8" Craftsman (don't know who made it for Sears in the 80's)... all analog type. I have no issues with any of them, they never run out of batteries, they feel more hefty (no plastic other than the dial face), and they are a bit more compact in the reading area. I am using a couple digitals for a poor man's DRO on my POS mill/drill, but for measuring, I can't see replacing my dials.

Am I missing the boat?

Mark

J Tiers
04-07-2011, 08:11 PM
Look Out...............

http://img.photobucket.com/albums/0803/jstanley/train.jpg

airsmith282
04-07-2011, 08:12 PM
i have digital calipers and i like them there really good for stuff that does not have to be 100% bang on , but for the bang on stuff i use a mircometer....as for the dial calipers there kinda cool but i don't use them at all in fact i don't own any as yet to busy putting money into other tools right now..

i prefer the digital calipers also because its saves some math and memory stuff for sure, plus you get the advantage of metric and SAE at the push of a button..

most of the work i do is metric based

38_Cal
04-07-2011, 08:19 PM
Airsmith makes a good point on the inch-metric conversion, and I do have a set of Red Chinese digitals that do that job if I remember to put in fresh batteries! :D But, I still prefer the feel of a dial caliper (eyes are too far gone for my quite accurate verniers) and use them most of the time that I don't use a mike. My 1" Starrett mike that I bought in 1975 lives in my shop apron pocket, and I rely on it for anything critical.

David

Dan Dubeau
04-07-2011, 08:21 PM
i have digital calipers and i like them there really good for stuff that does not have to be 100% bang on , but for the bang on stuff i use a mircometer....as for the dial calipers there kinda cool but i don't use them at all in fact i don't own any as yet to busy putting money into other tools right now..

i prefer the digital calipers also because its saves some math and memory stuff for sure, plus you get the advantage of metric and SAE at the push of a button..

most of the work i do is metric based

Bingo for me. Saves math, quick and easy to figure out the reading, and the batteries last damn near forever (mitutoyo) so that's not an issue. But it's different strokes for different folks I guess. At work there are guys who still use dials. I used to work with a guy (retired last year) who still used a vernier. Just a matter of personal preference I guess. I can read a vernier scale, but I'm certainly not as quick as with digital. Plus the opportunity for mathematical error as well (still there with digital too....inc/abs).

Dr Stan
04-07-2011, 08:23 PM
I never owned a pair of dial calipers for one simple reason, they can skip a tooth in the gear rack and become .025" out of calibration. Some of the shops I worked in banned dial calipers as just too much scrap was generated for this very reason. Until I bought my Brown & Sharpe digital I relied on vernier calipers and still have a 8" vernier caliper, a 12" vernier height gage, and a 48" vernier caliper.

Yes verniers are slower to read. That's why I have several of the HF 6" digitals around the shop along with a 12" in my tool box.

And oh yes, I forgot about the vernier bevel protractor.

Mark Hockett
04-07-2011, 08:31 PM
Each type have advantages and disadvantages. You will never get a chip caught in the rack on a digital caliper and you can convert from inch to metric with a digital. With a dial caliper the batteries will never go dead and you will never turn it on and accidentally zero it in the wrong place. There are other issues with both that others will touch on. I use both in my shop and I recommend using both to decide which you prefer.

J Tiers
04-07-2011, 08:33 PM
I never owned a pair of dial calipers for one simple reason, they can skip a tooth in the gear rack and become .025" out of calibration. Some of the shops I worked in banned dial calipers as just too much scrap was generated for this very reason.

NEVER had that happen, been using dial for 30 years.... Inch/Metric Dial calipers....... Both scales on ONE dial

With regular dial calipers, I just don't "see" the 0.025" "out of cal"....... Seems that if the pinion skipped, it would move the zero on the dial, but one simply re-zeros the dial, and off you go..... there isn't an absolute position as far as I know.

Are there people who lock the zero position? Aside from verifying the calipers with a block, it seems that locking the zero might be excessive, but.......

Black_Moons
04-07-2011, 09:07 PM
NEVER had that happen, been using dial for 30 years.... Inch/Metric Dial calipers....... Both scales on ONE dial

With regular dial calipers, I just don't "see" the 0.025" "out of cal"....... Seems that if the pinion skipped, it would move the zero on the dial, but one simply re-zeros the dial, and off you go..... there isn't an absolute position as far as I know.

Are there people who lock the zero position? Aside from verifying the calipers with a block, it seems that locking the zero might be excessive, but.......

I would think locking the zero would be rather important to keep from bumping the dial. That said, you should close the caliper and recheck that zero is zero often... And while some might say 'Thats a reason dial calipers suck!' you should be doing the same with your digitials, to make sure everything is in working order. (Low battery can make it skip a random distance, Usally its like 0.5"+ so its easy to tell, but could be much less, Contaminates can confuse it, a ding/scratch in the jaw could disturb it, etc etc etc)

Personaly, I just like digitial. But I can see dial calipers being as good, However I also am prone to buying really cheap chinese tools. Thier $20 digitial calipers are known to be very good. I havent heard much about chinese $20 dial calipers, but I would somewhat suspect with more moving precision parts theres more room for china to screw it up, or cheapen it to worthlessness. a $60~100 dial caliper would likey be dead on accurate as good as any equivilently priced digitial however.

MichaelP
04-07-2011, 09:15 PM
During machining I strongly prefer dial calipers (unless mike is needed). For general measurements I use both, dial and electronic calipers depending on a situation.

Dr Stan
04-07-2011, 09:39 PM
NEVER had that happen, been using dial for 30 years.... Inch/Metric Dial calipers....... Both scales on ONE dial

With regular dial calipers, I just don't "see" the 0.025" "out of cal"....... Seems that if the pinion skipped, it would move the zero on the dial, but one simply re-zeros the dial, and off you go..... there isn't an absolute position as far as I know.

Are there people who lock the zero position? Aside from verifying the calipers with a block, it seems that locking the zero might be excessive, but.......

The one case I remember well was when I was working as an IE for a defense contractor. One of the machinists cut a bunch of missile parts .025" short due to this very problem. All I can say is I've seen it happen on more than one occasion.

Mcgyver
04-07-2011, 11:12 PM
both have merits, dial is nice for the same reason a driver likes analog gauges...when roughing or grabbing stock a glance at the dial's position tells a lot whereas with digital you have to read and process, a small thing maybe, but like the paths worn diagonally across the grass everywhere, we are lazy creatures preferring the easiest route.

otoh, zeroing caliper where you want to measure a difference or switching between metric imperial has its moments.

J Tiers
04-07-2011, 11:21 PM
I would think locking the zero would be rather important to keep from bumping the dial.

I meant locking and sealing to "keep calibration"...... seems silly and unproductive, but can't see how there COULD be an issue of 0.025" otherwise. Unless, of course, the user NEVER checked zero..... seems like a quick check would have avoided scrap parts..... And why was he using calipers anyway.... because they are not so accurate?

I check zero all the time, and I don't particularly believe it when zero changes.... I look for the bits of crud in the jaws then. Close and sight looking for light between them ...... you see it, you will also see little shadows of grit in there.

914Wilhelm
04-07-2011, 11:54 PM
The biggest problem I have with my digital calipers is they shut off or act screwy when it's cold in the shop despite fresh batteries. As a result I will have to keep them inside my coat to keep them warm. It can be a pain when the pointy parts snag on my clothing. As a result I keep an analog handy.

Evan
04-08-2011, 12:47 AM
I can't stand digital calipers. I use dial calipers for several reasons mentioned above, especially the ability to read it like a clock. Most people can read a clock that doesn't have any numbers on it and the same applies to calipers. At a glance I can see how close I am to a particular reading or instantly determine if I have the right tap drill.

Metric conversion is also no problem. I also like the ability to read between the lines, which you can see in this photo is entirely practical. These calipers read and instantly convert metric/inch. They are also very accurate.

http://metalshopborealis.ca/pics5/caliper2.jpg

becksmachine
04-08-2011, 02:23 AM
Digital calipers will let you read the center distance on 2 equally sized holes directly. This also works for bolt circle diameters if you have 2 holes diametrically opposite.

Dave

gmatov
04-08-2011, 02:50 AM
Wilhelm,

With your caliper in your coat in your cold shop, you are not doing precision work, any way. Why be concerned if all you have to be is close?

Jerry, I never picked up a mike or any caliper that I did not wipe off the jaws or the anvil of a micrometer. My digitals get Zeroed, my Dials get checked FOR Zero, and if anybody gets a "skipped tooth" he should be ashamed of himself for forcing the measuring instrument to jump over an obvious problem with his tool. If my caliper would not. move, I would investigate WHY it hung up, NOT force it over a chip. AND, if it jumped one tooth, I would loose the lock screw, rotate the bezel, re-zero, and re-lock

The people we are conversing with are most likely the ones who also zero their dial indicators by moving the spindle to Zero instead of getting a "touch", plus a couple thou. Bring that needle up to Zero. Don't loose the screw and turn the bezel, and the dial, and MAKE Zero.

I like Evan's argument, too, BUT, I don't need the dual scale to determine a MM from 40 thou. If I caliper about 1/2 thou less than 40 thou, I am pretty close, tho not in the angstroms he works to, tho I don't know if he does so on diameters.
I have or have had all three versions, my eyes are not good enough, anymore to be sure with a vernier, but either dial or digital work quite well, and I never use either to determine a diameter on the lathe. THAT takes a micrometer. Get close with a caliper, spring, not digital, then sneak up with a dial mic.

AND both mic and work will be VERY close in temperature.

Cheers,

George

jugs
04-08-2011, 03:54 AM
The one case I remember well was when I was working as an IE for a defense contractor. One of the machinists cut a bunch of missile parts .025" short due to this very problem. All I can say is I've seen it happen on more than one occasion.

Is that the reason for missiles falling short of targets in collateral damage / friendly fire incidents ?? :confused:

john
:)

914Wilhelm
04-08-2011, 06:21 AM
George,

At one time I thought a caliper could be used for precise work but that thought long ago went out the window when I bought some decent micrometers. Most of the stuff I have cut my teeth on has been "Get er dun" farm sort of stuff. I was really fooling myself about the precision of (my) calipers and my ability to measure things till I started tring to make bearings fit bores. The sad reality of my situation has been a hateful pole barn that exaggerates the outside atmospheric conditions but it has taught me to compensate for thermal changes. I still recall figuring out temperature compensation the first time I turned out a bore (on a 70ish degree) day and it was too small after the part cooled off after the machining. With any luck I will be able to build myself an environmentally pleasant man cave this year and continue to turn perfectly good stock into annoyingly sharp barbs in comfort.

Wilhelm

J Tiers
04-08-2011, 08:34 AM
Jerry, I never picked up a mike or any caliper that I did not wipe off the jaws or the anvil of a micrometer. My digitals get Zeroed, my Dials get checked FOR Zero, and if anybody gets a "skipped tooth" he should be ashamed of himself for forcing the measuring instrument to jump over an obvious problem with his tool. If my caliper would not. move, I would investigate WHY it hung up, NOT force it over a chip. AND, if it jumped one tooth, I would loose the lock screw, rotate the bezel, re-zero, and re-lock


+1 on all of that!

AND ashamed of himself for never checking zero while working.

Dr Stan
04-08-2011, 09:24 AM
+1 on all of that!

AND ashamed of himself for never checking zero while working.

I'm in full agreement and so was my supervisor, the VP/co-owner of the company. Needless to say the machinist was fired for his incompetence.

Dr Stan
04-08-2011, 09:27 AM
Is that the reason for missiles falling short of targets in collateral damage / friendly fire incidents ?? :confused:

john
:)

The parts in question had nothing to do with the targeting system.

A.K. Boomer
04-08-2011, 09:28 AM
Can't imagine what it must be like to have to worry about "forcing" your calipers over a chip esp. when you have to go from a 6" measurement down to something under .250" and then back and forth --- How long does that take you to be sure your not going to damage your calipers?
I simply don't have the time,
Last set of dial calipers I had made it a week and they got knocked off the work bench and jumped teeth and hit the trash can,

To each their own but my digi's are running over 5 and 8 years strong now, have kicked out thousands of parts and ALL have passed inspection,

have hit the floor at least a half dozen times - have a 5/10ths last digit,
Are dirty as sin except for the jaws and the viewing screen and are accurate as you can expect from any caliper. and ohh yeah - cost me $18.00 and $24.00
and the metric conversion button comes in real handy.

Done with the dials - done with the worrying about slamming the jaws closed too sudden in fear of seeing the little needle indicator laying sideways inside the dial casing (my first set of dials) - as far as what I will be using stick a fork in them -- im done, done, done...
I need something far more practical. iv had over 3 pairs of dials and they are all residing in the landfill --- iv had only 2 pars of digi's and the originals are still working fine and are my back ups now, the 2 digi's have measured over 50 times the amount of parts that the 3 dials combined ever did.

just my two cents:p

Oldbrock
04-08-2011, 02:12 PM
I have a couple of digitals (presents) but trust my verniers, it can't suddenly zero itself somewhere other than zero. My verniers never run out of batteries and for precise measurements I always use my micrometers. I had a dial caliper once and it lasted a month before I gave it to an apprentice to play with and told him not to trust it for anything fussy. Verniers and mikes have no annoying habits to guard against. Peter

macona
04-08-2011, 02:21 PM
I have a 8" peacock dial. It got a little chip in the rack and I never even felt it when I passed it. Suddenly my caliper was not reading zero closed.

I like digitals. You can zero them anywhere to make differential measurements, switch to metric, reset to measure between holes, etc.

flathead4
04-08-2011, 06:48 PM
Evan,

What brand is the in/mm caliper you show back on post #15? I was trying to figure out how it would work with one needle but it looks like your's has two? So for each revolution of the black inch needle (.10"), the red mm needle moves one revolution (2mm) plus .54mm, right?

Tom

Evan
04-08-2011, 08:45 PM
I bought the tool from Lee Valley tools. It cost around $50 at the time and is well worth it. The black needle is 0.1 inch per rev and the red needle is 2mm per rev. They do not revolve in synchrony. It makes it very easy to convert from one system to the other and also to find near equivalences when the two needles align with each other and a common size.

I work in both systems all the time and many of my good instruments are metric. I learned metric alongside inch because my father was a scientist and science teacher. He strongly believed metric is superior because of the interrelation of the units which makes conversions from volume, mass, density and size far easier.

tyrone shewlaces
04-11-2011, 08:09 PM
Calipers, shmalipers.
Reading between the lines isn't an issue anyway, at least for me, since I only trust anybody's calipers, mine included, to be within a couple thou. Trust yours if you want to, but since I do this to make my living I don't take the chance. I use calipers to get a rough measurement and they're handy for scribing lines in dykem and such. My standard procedure is to get a rough idea or non-critical dimensions with calipers and use more accurate, repeatable tools for close-tolerance work.

So in my book, either dial or digital works OK and I don't have much of a preference really. Having said that, I do have one each 6" and 12" digital at work. At home I use whichever one I find first and often it's dial.

The one thing I have a strong opinion about is the stupid dial ones with .2" per revolution on the dial. I can't understand why anyone thought that was a good idea and hate using them when I found one in my hands. I'd just as gladly throw them in the trash as have to use them. I know they are no different to read really, but passing 100 twice on each rev can be confusing when you're not expecting it and I just think making those up was one of the great stupid ideas to be abandoned. I wonder what the sales pitch was and wish I was the boss so it could have been rejected. No advantage with them. Just pure goofy.

OK that's out of my system now.

Evan
04-11-2011, 08:54 PM
I trust my calipers. I use them to do light bearing press fits all the time. It's rare when need to haul out the mic. It isn't very often that you need absolute accuracy. What matters is repeatability. Repeatability is what digital calipers don't have since the best that a digital device can do is +- one count on the display.

flathead4
04-11-2011, 11:12 PM
If you're just copying parts, you don't even need a "dial" caliper. A fairly good set of plain calipers will do as long as your technique is repeatable.

Paul Alciatore
04-12-2011, 12:56 AM
I'm in full agreement and so was my supervisor, the VP/co-owner of the company. Needless to say the machinist was fired for his incompetence.

Was he REALLY a machinist?

I wouldn't dream of taking a measurement with any kind of caliper or mike without first cleaning the jaws or anvils and CHECKING THE ZERO.

I have never seen a dial caliper jump a tooth. Just how hard to you have to drop it or slam it against something for it to do that? I mean, is a 6' person tall enough or would he need a ladder? I do have one that moved about 6 or 7 thousanths after being dropped. But that is not a whole tooth. Something else moved.