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False readings on digital micrometer solved

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  • False readings on digital micrometer solved


    Got a Mitutoyo digital micrometer that was giving false readings. It was only doing it occasionally. Luckily, most of the time the false readings were way off and wasn't too much off a problem. Trouble was the erratic readings some times came close to expected readings and part was turned undersize on the lathe.

    Fussing over the mike going batty and would have to replaced it, when noticed that the only time it was giving false reading was when wanting to make the final finish cut. It is a habit that when miking for the finial cut the mike would be placed on a stainless steel cover that was on the backside of the cross-slide. This was handy to pick up and check the size after the final cut.

    Guessing the variable frequency drive located in the base of the lathe was the culprit. Changed habit of laying mike on lathe and no more problems with wrong readings on mike. Thought I would mention this just in case it might happen again to someone.

  • #2
    I bought a mitutoyo digital mike ten years ago and had it skip two thou a couple of times . I do not think it had the same cause but it is something to consider.mostly it just decorates the inside of my tool chest now.

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    • #3
      Mine was skipping a while back too, and I have no high-frequency generators nearby. It fixed itself eventually.

      Maybe it was the gov'mint trying to read my thoughts with a microwave!

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      • #4
        Classic cases of UFO activity.

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        • #5
          I have a GFCI plug just off to the side of the Miller Syncro 250 welder that I have. When ever I TIG weld the GFCI trips.

          The only thing that I can up with is, the high frequency is bleeding into the circuit and causing the problem.

          Will not cause any lost parts though, just a pain as I forget about and when I want to use the grinder the GFCI has to be reset.
          Charlie
          Don\'t ask me to do a dam thing, I\'m retired.
          http://home.earthlink.net/~kcprecision/

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          • #6
            If the micrometer is new send it in for warranty or email Mitutoyo.

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            • #7
              <font face="Verdana, Arial" size="2">Originally posted by charlie coghill:
              I have a GFCI plug just off to the side of the Miller Syncro 250 welder that I have. When ever I TIG weld the GFCI trips.
              The only thing that I can up with is, the high frequency is bleeding into the circuit and causing the problem.
              Charlie
              </font>
              The high freq. from the welder can be annoying.

              I have florescent lighting and when I TIG weld the high freq. makes the lights go on and off with the fluctuation of the high freq. I notice it in the reflection from the back of the helmet.

              My neighbors must think I'm buildin Frankystein with the electrical noise and ALL the lights going crazy, at night. JRouche
              My old yahoo group. Bridgeport Mill Group

              https://groups.yahoo.com/neo/groups/...port_mill/info

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              • #8
                Thrud wrote: “If the micrometer is new send it in for warranty or email Mitutoyo.â€‌

                Thrud, looked up the phone number for Mitutoyo on the internet and called.
                Asked for a technician regarding digital micrometer. After 3 transfers talked to what sounded like an oriental gal reading off a computer screen. Explained my problem. She said it sounded like the encoder needed recalibrating and being it was over a year old it would cost $49 dollars plus S&H.

                Got another Mitutoyo digital micrometer with the ball ends and had never used at the lathe. So did some experimenting. First thing did was put both micrometers on .10000â€‌ and locked (thumb screw). Ran the lathe and was unable to get false readings. Loosened the locks on the micrometers and the older mike that had problems would give a false reading (after much trying) seemed most likely false reading if the spindle of the mike touched metal. Sometimes instead of false reading would get “Error –o5â€‌ reading. With the newer ball end mike was also able to get error message and false readings. One time got error message when was about 6â€‌ from touching the lathe. Unable to get false readings without the lathe running, even by pounding the mike in the palm of my hand.

                Guessing the VFD puts out a high frequency carrier that is the problem. I can live with this problem by changing my habits and only take the mike off of wood drawer when lathe is off. My old eyes like reading the digital numbers and my feeble brain likes zeroing the mike on wanted size and not making some dumb math error when making that next cut.

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