Darn Mitutoyo mic wore out on me.

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Richard_W
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Darn Mitutoyo mic wore out on me.

Post by Richard_W »

Not sure where to post, so I thought this would be a good place.

At work I am training my replacement. I am still debating my retirement next month, since that will be 50 years working in the trade.

Anyway I was going to show the kid how to use a telescoping gauge using a setting standard for a 3 to 3.5" 3 point bore micrometer. When I showed him and measured the gauge with my 3 to 4" micrometer. I discovered my micrometer was off by .0005". So I grabbed a new company micrometer to show him. I later got back to my micrometer and checked it with gauge blocks. I reset it with a 3 inch gauge block. Then checked it at 4" with a gauge block. Then I thought I would check it at 3.500 and it tuned out to be .0005 off. So now its time to smash it and get a new one. I don't like to throw worn out measuring tools in the trash. Because some fool would take it and use it. Or worse yet sell it to some unsuspecting buyer looking for a bargain. I have had that happen.

I suppose you are wondering why I would buy another one? I have a small home shop and will need my tools. Even though the company wants to buy them from me.

While I am here I did have the chance to show the new kid on the use of thread wires. I had just wrote a program for a part. I was showing him what I am going to do from start to finish. Seems to be a really bright kid who seems to learn real fast. After I had him type in the program and ran it through the graph. He ran the first part until the threading cycle. But he got the look of terror when I brought out the thread wires. Seems the few times he had used them in the past was not a good experience. He had problems dropping the wires and trying to find one in the chips. I told him the small painters tape on them made them easy to find. He noticed that a good deal of the wires in my set had painters tape on them. So we run the thread cycle and I said we needed to make another cut about .015 deeper. I ran the thread cycle again and measured the thread with the wires. Adjust the offset another .008" and ran the cycle again. This time the thread wires measured within .0003 of my desired diameter. I filed-ed the top of the thread lightly and touched it for a moment with scotch-brite. The nut went on first try. He was totally amazed because this took less than 10 minutes even with explanation of what I was doing. His college experience was quite different from what he had just seen. I think he is going to do just fine.

Still not sure about my retirement. The company did offer me the option to work part time. Which seems kinda odd, since the kid will be running my machine.

Richard W.
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Bill Shields
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Re: Darn Mitutoyo mic wore out on me.

Post by Bill Shields »

There are adjustments on mics
Too many things going on to bother listing them.
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Harold_V
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Re: Darn Mitutoyo mic wore out on me.

Post by Harold_V »

Bill Shields wrote: Sun Sep 19, 2021 3:33 pm There are adjustments on mics
But none that will rectify error in lead.

H
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Steggy
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Re: Darn Mitutoyo mic wore out on me.

Post by Steggy »

Richard_W wrote: Sun Sep 19, 2021 2:02 pmAt work I am training my replacement. I am still debating my retirement next month, since that will be 50 years working in the trade.

Retire if you can and enjoy life without the annoyance of having an alarm clock wake you up each morning. :D Your remaining years will go by in a flash—being the late septuagenarian that I am, I can vouch for that. Best to enjoy them while you can.

I discovered my micrometer was off by .0005"...So now its time to smash it and get a new one.

No it isn't. If you know about the half-thousandth error and it is consistent over the instrument's full range, then just add or subtract as needed to get the true measurement. I have a 4"-5" mike that I know is consistently 0.0002" too high. I see no reason to scrap it.

While I am here I did have the chance to show the new kid on the use of thread wires...But he got the look of terror when I brought out the thread wires...His college experience was quite different from what he had just seen. I think he is going to do just fine.

There's an old adage that goes something like: Those who can, do. Those who can't, teach. Today's colleges seem to have a preponderance of the latter on their staff, and I all-too-often see the results in the current generation of college grads. Putting it in familiar terms and to borrow a phrase from my buddy Carl, they know all about railroads but don't know squat about railroading.

Still not sure about my retirement. The company did offer me the option to work part time. Which seems kinda odd, since the kid will be running my machine.

If you can use the extra cash and the hours are flexible, and you like the work, why not? I retired this year after some 53 years in the workforce (it wasn't until chronic medical problems arose that I even considered retirement), but continue to support a few clients, since the demands aren't too great and I like the work. The money that comes from doing so goes toward paying my Medi-Gap insurance premiums, with leftovers going into my locomotive slush fund.

Given what is going on right now in the USA with the current regime, I'd say take advantage of any situations where you can make some money without having to work full time. You may wish you had the money in a few years when the bill comes due for all the spending that is being proposed.


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EDIT: Fixed an omitted qualifier.
Last edited by Steggy on Sun Sep 19, 2021 3:50 pm, edited 1 time in total.
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Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
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Harold_V
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Re: Darn Mitutoyo mic wore out on me.

Post by Harold_V »

BigDumbDinosaur wrote: Sun Sep 19, 2021 3:37 pm No it isn't. If you know about the half-thousandth error then just add or subtract as needed to get the true measurement. I have a 4"-5" mike that I know is consistently 0.0002" too high. I see no reason to scrap it.
The OP clearly stated that the error is not consistent. It IS time to scrap the instrument unless one has no need to be concerned with tenths, and I am clearly having a problem thinking that would be the case.

H

Edit: A comment about retirement.

I retired when I was 54. I am now 82. My only regret has been that I was sorry to not have retired earlier.
My shop has expanded tenfold since the days I used it for gain. It is used for my pleasure, not for making money. I have never run a job for another for pay since I retired. It is done gratis, or it isn't done at all.
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Steggy
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Re: Darn Mitutoyo mic wore out on me.

Post by Steggy »

Bill Shields wrote: Sun Sep 19, 2021 3:33 pmThere are adjustments on mics

What Harold said.

You can adjust out the slop in the threads, but only if that slop is consistent over the instrument's full range. Just as lathes tend to show more way wear near the headstock than elsewhere, it's been my experience that measuring instruments also experience uneven wear from years of use. A few years ago, I had to scrap a Craftsman 1" mike I had bought in the 1960s because thread slop near the "small" end was such that when adjusted out, the instrument would bind near the "large" end.
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Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
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Steggy
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Re: Darn Mitutoyo mic wore out on me.

Post by Steggy »

Harold_V wrote: Sun Sep 19, 2021 3:41 pm
BigDumbDinosaur wrote: Sun Sep 19, 2021 3:37 pm No it isn't. If you know about the half-thousandth error then just add or subtract as needed to get the true measurement. I have a 4"-5" mike that I know is consistently 0.0002" too high. I see no reason to scrap it.
The OP clearly stated that the error is not consistent. It IS time to scrap the instrument unless one has no need to be concerned with tenths, and I am clearly having a problem thinking that would be the case.

I agree—I belatedly realized I didn't correctly qualify my statement to say the error must be consistent.
———————————————————————————————————————————————————————
Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
Richard_W
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Re: Darn Mitutoyo mic wore out on me.

Post by Richard_W »

Harold_V wrote: Sun Sep 19, 2021 3:41 pm
BigDumbDinosaur wrote: Sun Sep 19, 2021 3:37 pm No it isn't. If you know about the half-thousandth error then just add or subtract as needed to get the true measurement. I have a 4"-5" mike that I know is consistently 0.0002" too high. I see no reason to scrap it.
The OP clearly stated that the error is not consistent. It IS time to scrap the instrument unless one has no need to be concerned with tenths, and I am clearly having a problem thinking that would be the case.

H
Correct Harold.
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Bill Shields
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Re: Darn Mitutoyo mic wore out on me.

Post by Bill Shields »

Eh well...it you want to sell it. .give me a call
Too many things going on to bother listing them.
pete
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Re: Darn Mitutoyo mic wore out on me.

Post by pete »

.0005" off is a lot and especially so when it's not linear over the whole measuring range. But Mitutoyo offers both repair and proper test re-calibration if you want it. If that mike is still a current model it's an option worth considering. I dropped my 0"-12" Mit dial calipers just once and was amazed even the needle was then forced into the dial face and not a mark on the crystal. I still can't figure out how that would be possible but it happened. I sent them in to there only repair facility in Canada and requested a full repair and re-calibration. They came back in as new condition for about half the price of a new set. So if they still have repair parts for that mike it could still be cheaper than buying a new one. An email about replacing the only two parts that could be worn as well as what series of mike it is should get you a fairly accurate price. Recalibration would also check and verify the anvils flatness so that could rule out a repair as being non cost effective.
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Re: Darn Mitutoyo mic wore out on me.

Post by SteveM »

As people have said, if the error is a constant, it's just a matter of adjusting the barrel until it is correct.

Testing with gauge blocks that are, for example, in increments of 0.100" won't tell you much because you are at the same rotation of the spindle.

Also, if your anvil faces aren't parallel to each other, you can get seemingly random errors when measuring round stuff.

A test kit like this:
Mikemaster.jpg
tests at different rotations of the spindle, and the test surfaces are curved so you get a line contact.

The different rotations will tell you if it is spot on in one spot in the rotation and off in others.

The line contact will show errors in different rotations when that line contact is at different rotations of the spindle.

Think if your spindle face was one degree out. A gauge block will measure the highest point no matter the rotation. A round surface will give a different reading when it is on the high spot than it will be 90 degrees to that.

The kit new is a bloody fortune, but you can get them used on ebay. I have a set and one of these days I'm going to send them out for calibration just to be sure, but I have tested several mics with them and they all checked out, so either all of my mics are messed up the same or the tool is OK. If you get one, be sure that it comes with the original test certificate, which shows the actual dimension out one decimal place more than what is stamped on the tool.

You can do a quick test for spindle flatness with two gauge pins that will test the spindle at a 90 degree difference. You can also put a small gauge block in and rotate it - if you see the point of rotation is on the outside edge of the spindle, that's the high point.

Steve
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Re: Darn Mitutoyo mic wore out on me.

Post by RSG »

Time for a new mic and to exit the job Richard_W!

Like Harold, I retired early at 54 and don't regret it (only been gone two years). Oddly I find I have less time to do the things I enjoy than when I worked full time...LOL
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