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Problem with 1" outside micrometer

My 1" digital OD mic which I've had for about 3-4 years started doing the following. After turning it on, I zero it and back it out well beyond .3" then inward to a little over .3" to measure case neck OD without and with a bullet inserted (to get case neck tension), sometimes it will read in the .2s" when I know it should read in the .3s. It started doing this about 2 weeks ago. I changed the battery last week, but sometimes it is still doing this. I checked the voltage on the new battery and it is correct (2.99, 3.00 and 3.00 v measured 3 times). Please advise what I should do with this mic, and if a replacement is needed, please advise. Thank you for your help!
 
Asks question about digitial mics and gets told to learn how to read mechanical micrometers.


What brand micrometers are they ?
 
I can tell you what I would do.
I would disassemble the thing as carefully as possible, look at the innards and contemplate life choices. Then, if by some miracle I was able to fix it, great!
If not, pitch it and by a better one.

As far as no digital measuring tools, I have no such prejudice. A good digital mike can consistently measure to 0.00005". I have only needed that level of precision once in my machining career, but, boy oh boy did it ever save the day.
 
I am grateful for all of your feedback. I also have a mechanical 1" ball mic for measuring case neck thickness to .0001" and use it regularly, so I think I would have no problem with a standard 1" OD mechanical standard mic. I have a question. I clamp the mic (either one) on about a 6" tall a mic stand on my workbench for ease of handling both mic and cases at the same time, and can easily read the hash marks facing me on the mic that read in .001" increments, but have to pick up the stand (with the mic clamped) and turn it around to read within .0001" for each case, which is the accuracy needed for turning necks to case neck thickness (I can include a pic of this arrangement if you wish). However, since I may be measuring 30-60 cases in a batch, it gets monotonous having to pick up the stand/mic and turn it around so I can read to the .0001" value for each case. Is there an easier way?

What I'm hearing from you, since I think I would screw up dismantling and reassembly my current digital mic, is that I need to get a new one. Which brand/model do you think I should get that would give me consistently reliable measurements to .0001" recognizing there is a bit of practice and touch involved?
 
What I'm hearing from you, since I think I would screw up dismantling and reassembly my current digital mic, is that I need to get a new one. Which brand/model do you think I should get that would give me consistently reliable measurements to .0001" recognizing there is a bit of practice and touch involved?
I agree with Doug Beach, a Starrett or a Mitutoyo mic is the choice. I use my Starrett,(which I bought in 1962) regularly in reloading.
The mic stand is a good idea, and it is a pain to pick it up and turn it over to read the .0001 marks BUT it does keep you from "warming" your mic with the heat from your hands during a long session. Keeping a mic in your hands and trying to measure to .0001 on a cartridge case that may not be actually round can lead to errors. Wearing a pair of very light cotton gloves will help on the heat transfer.
 
I am grateful for all of your feedback. I also have a mechanical 1" ball mic for measuring case neck thickness to .0001" and use it regularly, so I think I would have no problem with a standard 1" OD mechanical standard mic. I have a question. I clamp the mic (either one) on about a 6" tall a mic stand on my workbench for ease of handling both mic and cases at the same time, and can easily read the hash marks facing me on the mic that read in .001" increments, but have to pick up the stand (with the mic clamped) and turn it around to read within .0001" for each case, which is the accuracy needed for turning necks to case neck thickness (I can include a pic of this arrangement if you wish). However, since I may be measuring 30-60 cases in a batch, it gets monotonous having to pick up the stand/mic and turn it around so I can read to the .0001" value for each case. Is there an easier way?

What I'm hearing from you, since I think I would screw up dismantling and reassembly my current digital mic, is that I need to get a new one. Which brand/model do you think I should get that would give me consistently reliable measurements to .0001" recognizing there is a bit of practice and touch involved?

https://www.mscdirect.com/browse/tn...nts=Maximum+Measurement+(Decimal+Inch):1.0000


anything on that page will do what you need it to do. Traditional mics should last forever , but as you mentioned, difficult to read in low light or have got to be rotated to read tenths.
 
My 1" digital OD mic which I've had for about 3-4 years started doing the following. After turning it on, I zero it and back it out well beyond .3" then inward to a little over .3" to measure case neck OD without and with a bullet inserted (to get case neck tension), sometimes it will read in the .2s" when I know it should read in the .3s. It started doing this about 2 weeks ago. I changed the battery last week, but sometimes it is still doing this. I checked the voltage on the new battery and it is correct (2.99, 3.00 and 3.00 v measured 3 times). Please advise what I should do with this mic, and if a replacement is needed, please advise. Thank you for your help!
Check the battery connections
Sometimes there is not enough spring pressure to make a good enough contact for it to read as you sweep
You can clean the contacts also with a #2 pencil eraser tip.
A small folded up piece of paper on top of the battery then the cap put on...
...can help apply extra battery contact pressure
---
I have a Mitutoyo digital caliper that I kept replacing batteries, since it kept acting like the battery was dead and ended up doing what I just told you to fix it...
it is still iffy at times...it is now my "Beater Caliper"
---
This is one of those things, that is a reason not to trust Digital equipment
since you don't know what could be going wrong, if its going wrong, how to troubleshoot whats going wrong etc
---
Perhaps if you like digital, try MECHANICAL digital mic's
 
Buy a Mitutoyo digital.
They're awesome! Could I do without them? Sure. 95% of the time I use mechanicals but the digitals have tricks up their sleeves that can speed up your work. Say I want to cut a tenon to 1.058". I dial the mic to 1.058", hit the zero/abs button and the display now shows zero. Open up the mic and start cutting your tenon. Check size and it'll directly read out how far you have to go to hit your target of 1.058" which is your zero on the mic. No mental math to do when dialing the cross slide, you know exactly how far you have to go. Need a sanity check because you're nervous and don't trust it? Hit it with your Mit digital calipers real quick to confirm where you are. Oh yeah, that same trick works on the calipers as well.
 
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They're awesome! Could I do without them? Sure. 95% of the time I use mechanicals but the digitals have tricks up their sleeves that can speed up your work. Say I want to cut a tenon to 1.058". I dial the mic to 1.058", hit the origin button and the display now shows zero. Open up the mic and start cutting your tenon. Check size and it'll read out how far you have to go to hit your target of 1.058" which is your new zero on the mic.
Still gotta divide by /2 :P
Just kidding, that is one of the handy features of a digital
 
Depends on your lathe. Some cross slides cut to radius and some are diameter. Gotta know your instrument :)

My Rockwell reads and cuts to diameter.
oh that would screw me up big time , if I didn't have to divide by 2 all of a sudden
I'm too used to it, couldn't handle it
 
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