Knowing your calipers

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  • rabiddawg
    Chieftain
    • Feb 2013
    • 1664

    #16
    Originally posted by Adam Lilja View Post
    I find digital calipers to be worthless By ballpark I mean +-.002
    I can live with that but I am glad to hear my barrel maker can't!
    Knowing everthing isnt as important as knowing where to find it.

    Mark Twain

    http://www.65grendel.com/forum/showt...2-Yd-Whitetail

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    • The Profit Joseph Sith
      Warrior
      • Nov 2016
      • 596

      #17
      Originally posted by LR1955 View Post
      1075:

      For reloading it won't make a difference. Just use a consistent amount of pressure each time if you think it matters.

      I do hear you though about changes depending on how much pressure you put on the calipers. Sure will give different measures. Never seen it go as far as several thousandths though. Maybe a thousandth? Anyway, it doesn't matter when measuring for handloading.

      LR1955
      What's a caliper?

      When i was a kid i used dial calipers (mititoyo) and for some reason got a kick out of measuring my hairs (not the short ones) i think this would be a good way to practice tension because you can crush it somewhat easily but would still have to kinda try. Technically there are very specialized ways to measure soft things precisely lime rubber or foam. Anyway you shouldn't see more than about .0005" deviation in pressure. Or there is dirt in the gear track or pickup is dirty or cheap calipers? I have used tons of certified mesuring tools at boeing and have mititoyo dig o matics and a couple pairs of autozone digital calipers as well. The cheap ones are actually pretty decent...

      What i have issues with is the micrometers.. its easy to over torque a threaded screw measuring system. Especially the older ones without any kind of ratchet tensioner. There again i find a hair of some sort is good for practice. They Should measure about .0015-.002" depending on how thick your hairs are..

      EDIT Mr. Lilja is indeed correct if I remember correctly even the certified digital calipers @ boeing are certified to -/+ whatever. nothing is ever exact... And i agree i kinda prefer dial over digital its amazing how much more info you get from them. But I do like my digitals more for what i do. And they are very reliable if good quality. And also 2nded jf you ARE trying to use your calipers for to measure .000x" you should definitely use micrometers.

      All that said boeing uses nothing but digital everything now. And their gauges are VERY accurate. Its easier to have fewer moving parts with digital. I used $20k torque wrenches that had no moving parts but meaured strain in the head and plug into your laptop to record torque values. Wich you can just upload into velocity program to sell your jobs.
      My last boss had digital mics that would read out to .00000x" not sure of their accuracy though. Not really ever needed if you ask me. That's getting into ic chip circuitry size territory... Which would be measured optically...
      Last edited by The Profit Joseph Sith; 02-07-2017, 03:08 AM.

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      • Klem
        Chieftain
        • Aug 2013
        • 3509

        #18
        Consistent dialling.
        Never seen them on calipers but on micrometers they often come with a secondary spring loaded dial that acts like a torque wrench. You spin the dial closing the jaws until it comes up against the object you are measuring and then the secondary ratchet click over at the same torque each time. Called a ratchet screw, friction dial or ratchet dial.


        I've never really needed the extra precision that a micrometer gives you over a set of calipers. Calipers do 99% of all the measuring I ever do when reloading.

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        • explorecaves
          Warrior
          • Sep 2014
          • 284

          #19
          Originally posted by LRRPF52 View Post
          I'm interested to hear what some of you with industry standardization experience have to contribute, as well as those like LR1955 who have been reloading for decades.

          One rule of thumb is to always zero out your calipers before taking a measurement. This involves:

          1. Wiping the caliper jaws clean,

          2. Closing the jaws to mechanical zero,

          3. Confirming that the gauge indicates "0".
          4. Take your measurement 2-3 times

          5. close jaws to mechanical zero

          6. confirm zero was maintained (too much pressure while measuring will cause the zero to drift)

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          • wraith1516
            Warrior
            • Dec 2014
            • 316

            #20
            Does any one know of any where to have a set of digital calipers repaired i have a mititoyo calipers that have a issue with draining the battery and won't read anything over 3 inches without giving an error or am I just out $275

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            • explorecaves
              Warrior
              • Sep 2014
              • 284

              #21
              Originally posted by wraith1516 View Post
              Does any one know of any where to have a set of digital calipers repaired i have a mititoyo calipers that have a issue with draining the battery and won't read anything over 3 inches without giving an error or am I just out $275
              I would contact mititoyo directly.... http://www.mitutoyo.com/support/repair-service/

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              • wraith1516
                Warrior
                • Dec 2014
                • 316

                #22
                I did basically would be cheaper to buy a new set they are like 20years old

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