A Novel Approach to Reading the Micrometer

T

Tom Griffin

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This is my first request, courtesy of a member from one of the other forums where I hang out.

When I taught high school machine shop in the 70's, one of the first things I taught my students was how to read the micrometer. I used a method involving pocket change and it worked very well.

Tom

[video=youtube_share;UQHKAcQzS3Q]http://youtu.be/UQHKAcQzS3Q[/video]
 
Tom, that's the best explanation of how to read a mike that I've ever seen. Well done and thanks for sharing! Bill
 
Thanks Bill, glad you enjoyed it.

Tom
 
When I have an important measurement involving a micrometer or a depth gauge there are times where I cheat. I use my digital calipers to check the opening on the mike, or the extension on the depth gauge and confirm that my measurements are correct.
 
Tom thank you for sharing. I work on clocks and some stuff is imperial and some stuff is metric. I recently got a metric micrometer and am having to get my head around the "new" system.

Very good video.
 
Someone mentioned the metric thing on another forum so I dusted off a metric mic of mine and found that the technique works just as well on a metric micrometer. Just use dollars for the millimeter divisions (25), half dollars for the division between them and pennies for the divisions on the thimble (50). Add them all up and place the decimal point after the millimeter value.

Tom
 
I thought the explanation using pennies, quarters and dollars was outstanding and I picked up on it right away, but sorry to say I got completely lost with the last explanation on the ten-thousandths and wasn't sure how to do that. I watched the video three times. I'm not too bright either, so I'm sure it was my fault. My mic, btw is exactly like the last one you showed so I'd be interested in learning that last step, even though I probably would normally not need that level of precision for what I do.

Anyway, thanks. Anything that helps newbees is right on with me!

(The other hard thing I have is figuring decimals to fractions (or visa-versa); I use Machinery's Handbook and cheat). Going from decimal to imperial even harder, using handbook.
 
I thought the explanation using pennies, quarters and dollars was outstanding and I picked up on it right away, but sorry to say I got completely lost with the last explanation on the ten-thousandths and wasn't sure how to do that. I watched the video three times. I'm not too bright either, so I'm sure it was my fault. My mic, btw is exactly like the last one you showed so I'd be interested in learning that last step, even though I probably would normally not need that level of precision for what I do.

You are probably over thinking it. Once you get the thousandths figured out (it sounds like you got that part worked out), if a mark is showing between the thousandth divisions on the thimble (First pic below) add .0005. If more is showing, look on the vernier scale on the barrel and see which numbered line aligns with any division on the thimble (only one will align). In the second pic below, it's the number 3 line, so add an additional .0003. So the reading shown is .4718" (.471+.0005+.0003). Make sense?

You are correct though, you'll probably never have a need for a tenth reading mic unless you have a surface grinder or a toolroom lathe, they can work to tenths.

Tom
 
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Tom, I got it now. That's pretty weird how that's done but you explained it perfect and with photos too!
 
Great.

The concept of using a vernier scale can be a bit difficult to understand, but vernier scales were the way it was done on height gauges and calipers before the advent of digital readouts.

Tom
 
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