Can we talk...

[montana_charlie]

...about micrometers?

Having seen the electronic micrometer owned by Ben (in another thread), I am inclined to purchase one. As a start into that subject, I went shuffling around among the eBay pages.
I'll decide later if I want to buy new, or try a used one, but I have two questions that keep nagging at me.

Micrometer "X" comes with a fitted case, fresh battery, instruction manual, and a spanner. I downloaded the instruction manual from the manufacturer's website, just to learn what I can about the instrument.

Pictures tell me what not to do with the tool.
I shouldn't expose it to temp extremes, pour liquids on it, drop it on the floor, or feed it to my cat.

One picture seems to say I shouldn't touch it, and another appears to warn me against turning the knob (thimble?). (What's up with those?)

Moving on, I am versed in replacing the battery, setting the instrument to 'zero', and translating all (both) of the error codes I am likely to see.

Having absorbed the entire manual, I find my self with two areas of knowledge unfilled, and that brings me back to my 'two questions'.

1. I am not actually told which 'knob' to turn to take a reading. There is a long, fat one...and a short, skinny one on the end of the big one.
The last cautionary picture I mentioned (above) seems to say 'don't turn the big knob' but it may be saying 'don't turn it counter-clockwise'...I am not real sure what it wants me to understand.

2. I have no idea of why this micrometer (and all of the others I looked at) come with a spanner. The manual does not mention it's existence at all, and I already know a coin is an approved tool for opening the battery cover.

The spanner (for this electronic mic) is identical to those supplied with manual instruments, so a guy with experience in using either type should be able to inform me about it's purpose.

That leaves the 'knob question'. Do you turn the big one as a coarse adjustment, then switch to the little one for the final reading?
And, if it is illegal to turn a knob backward (seemingly indicated by the picture), how do you open the anvil faces?

Can somebody mentor me in the use of a micrometer...or should I just stick with my dial caliper?
CM

[fourarmed]

Whenever the subject of mikes comes up, I recall one of my colleagues who was teaching a physics lab. A student came up holding a mike and said "What are we supposed to do with this c-clamp?"

Obviously you have to turn it ccw to open it. When closing it, the small knob will only turn so tight, then it slips. The idea is that you screw it down on the object to be measured with the same torque every time. I think most people who are experienced with their use eventually take the measurements using the large barrel, relying on "feel" to produce the same torque each time.

The spanner is for setting the zero reading. Offhand, I would not think that would be needed on a digital with an electronic zero, but I have never used one.

[454PB]

I've never used a digital micrometer, but I have used a digital caliper. They are temperature sensitive, but that shouldn't be a problem in the controlled environment of a reloading room. All precision measuring devices require the same gentle handling, so dropping any of them is verboten.

The problem I had with the digital caliper I used was that it always seemed to have a dead battery when I needed it the most, and that it had to be zeroed each time it was turned on. It acted about like the electronic powder scales I have, very finicky, temperature sensitive, and more trouble than just grabbing my old balance beam scale.

[montana_charlie]

Thanks, fourarmed.
Your casual and straightforward-sounding reply caused me to think that using a mic (unlike loading for BCPR and casting lead into bullets) might not be rocket science, after all.

With the belief that the common man can master a procedure which is probably pretty intuitive anyway, I looked again at those instructions. The picture which seemed to say 'don't touch this mic' was actually a caution against 'disassembling it'. The screwdriver didn't catch my attention on the first time around.

Upon further study, the one which I thought warned against CCW turning of the thimble was actually telling the user not to open the unit beyond it's 1 inch capacity.

I'll continue to wonder about the spanner, but (like you) I'll consider it to be 'no big deal' until the day when I actually feel the need to use it.

CM

[No_1]

CM,

In my 35 years of using mic's, I have yet to use the spanner. It is for adjustments when the mic gets out of tolerance. I have found that with good care (such as what we do with all our guns/reloading equipment) a good mic should last almost forever. Forget about the spanner but please continue reading....

I am guessing you want the digital mic to help with seeing the numbers as well as ease of reading it. Have you considered a "digit mic" which is simular to a digital mic with the exception that it is mechanical (the counter is more of a mechanical "odometer"). This would save the grief of finding the battery dead. There are many brands to choose from (most around ~$40). I will refrain from listing any here because I do not want this to turn into a "Ford vs. Chevy" discussion.

Robert


Thanks, fourarmed.
Your casual and straightforward-sounding reply caused me to think that using a mic (unlike loading for BCPR and casting lead into bullets) might not be rocket science, after all.

With the belief that the common man can master a procedure which is probably pretty intuitive anyway, I looked again at those instructions. The picture which seemed to say 'don't touch this mic' was actually a caution against 'disassembling it'. The screwdriver didn't catch my attention on the first time around.

Upon further study, the one which I thought warned against CCW turning of the thimble was actually telling the user not to open the unit beyond it's 1 inch capacity.

I'll continue to wonder about the spanner, but (like you) I'll consider it to be 'no big deal' until the day when I actually feel the need to use it.

CM

[lathesmith]

Well, I ain't as old as a lot of guys here, but I guess when it comes to machine tools I am kinda old-fashioned. Heck, I even grind all of my HSS tool bits for the lathe! What,! you say, who uses HSS any more? Don't I know that CARBIDE is where it's at? Well, yes and no, but, anyway...
Like 454, I HATE dead batteries, and there is NEVER a convenient time for one. So, for the time being, in my little home hobby shop I'll stick with old-fashioned but surprisingly accurate, useful, and always-ready calipers and micrometers--without batteries. Like fourarmed implied, if you don't know the difference between a mic and a c-clamp, getting a battery-powered gizmo ain't gonna help you much.
lathesmith

[montana_charlie]

I am guessing you want the digital mic to help with seeing the numbers as well as ease of reading it. Have you considered a "digit mic" which is simular to a digital mic with the exception that it is mechanical (the counter is more of a mechanical "odometer"). This would save the grief of finding the battery dead.
Yessir, Robert, I did notice those mechanically digital micrometers.
Actually, I have always preferred 'analog' instruments because they allow you to read between the lines...without being confined to 'digits'.

I have tottered along for 60 years without a mic, and may not use one enough to do it justice. But, I think a battery powered unit will suffice as my one and only electronic measuring tool.

in my little home hobby shop I'll stick with old-fashioned but surprisingly accurate, useful, and always-ready calipers and micrometers--without batteries. Like fourarmed implied, if you don't know the difference between a mic and a c-clamp, getting a battery-powered gizmo ain't gonna help you much.
And so you should...use whatever you have faith in.

As for fourarmed's 'implication', I didn't read it quite as personally as you think I should have.
If you dump a mixed boxful on the table, I could probably pick the c-clamps out of the pile, Grasshopper.

[jhrosier]

I have a couple of nice, old micrometers that came from the Longbranch Arsenal when it closed.
Batteries not required and they will continue to work perfectly long after I'm put in the ground.
I also have a nice digital caliper that just stopped working one day. Mititoyo will "fix" it for about the price of a new one (fat chance.)
My old fashioned mechanical dial caliper and even older fashioned Vernier caliper are working just dandy.
I also have a self winding, 23 jewel Bulova watch that has functioned just dandy for the last half century.
There are just too many electronic gizmos waiting for an inconvenient time to fail.

Jack

[floodgate]

Ah, the Digitable Age!

Y'know, we're raising a whole generation who will never catch the meaning of "Twelve O'Clock High", or "Watch Your Six".

Fg

[nicholst55]

Ah, the Digitable Age!

Y'know, we're raising a whole generation who will never catch the meaning of "Twelve O'Clock High", or "Watch Your Six".

Fg


I just left a job teaching repair of electro-optical instruments and laser rangefinders for the Army. I added a brief explanation on the meaning of 'CW' and 'CCW' (that's Clockwise and Counter-Clockwise, not concealed carry) to my introduction class, because a lot of the kids coming into the Army don't know what they mean! And I'm supposed to teach them how to troubleshoot electronics and lasers! :roll:

[HeavyMetal]

At 55 I'm now working with the only computer I've ever bought!

I have the issue with electronic failure and take great steps to not have to deal with the issue. However some times you got to bite the Boolit.

My suggestion: don't buy a mic on the web! I'm sure there's a nice machine shop supply store in the area where you live. Go in ask to see both types of Mic's, electronic and the mechanical digital ones. Explain why you need it and that your not greatly versed in it's use, you will have someone in the place walk you through the procedure.

If they don't walk out! A good store knows that if you get what you want you will be back and, most importantly, you'll be back because they, the store, could provide you with answers! For that you may pay a bit more for your mic because, in all honesty, your paying for experience not just the product!

[scrapcan]

I agree on the analog instruments versus battery powered. I just traded a great digit mic for a digital mic and I would gladly go back to the digit.

also on the clutch/friction knob, it can be either the large or the small depending on manufacturer. My old vernier mic has the clutch on the small end knob, the new digital used the large as the friction slip. Just be careful not to cranck down the anvil while determining which is which.

[Sundogg1911]

i remember talking to my father years ago when I just got into reloading. I was going to buy digital calipers. He told told me they're toys for people that can't read tools. (He started His career as a machinist, and worked His way through Engineering school) I didn't go digital then, but I remember thinking that He was just old school. I almost bought a set a few years ago, but I'd hate to have my Dad roll over in His grave.
He did leave me His tools when He passed away, and for that reason alone i'll never switch.

[sundog]

Sundogg1911, loyalty is an admirable quality.

I cannot shoot well enough that I need the highest tech measuring equipment available. Besides, if it's anything other than a flashlight or portable radio (except maybe my digital scale for weighing boolits), it's just too techy for this poor ol' country boy.

[lathesmith]

CM,
When I mentioned in my above post about C-clamps and mics, I didn't intend that as an insult directed at you. I was only trying to make the point that sometimes, I believe simpler really is better--in this case, "analog" measuring tools vs. "digitized". I was not trying to offend, my apoligies for the mix-up.
lathesmith

[Bad Water Bill]

I have a Starret micrometer that I purchased in 1960 and have never had to run out in the middle of the night to get new batteries to finish a project. Life has gotten to complicated as it is let alone having to worry about things i can avoid. BWB:castmine:

[Wayne Smith]

Several years ago I bought a 1" Mic from Sears and have been trying to use it since. Have a digital caliper that I re-zero at times, and finally thought I might try to zero the mic. Gee, wiz, isn't it zeroed mechanically? I had assumed so. Lo and behold! When I tried to close it on itself it ended @ .002. I squeezed it hard and squeezed out .002 of grease between the contacts. Does this mean my measurements have been off .002 all this time? I'd guess so.

[Jon K]

Wayne,

Get a 1" Standard to check, and a spanner wrench to adjust the micrometer. the worse thing you can do is use it like a c-clamp, that's what the thimble on the end is for. Now you need to check if the faces are still square & parallel.

Jon

[bpost1958]

My Mitutyoia (sp?) absolute has a 20,000 hour battery life. It seems accurate and repeatable. Come to think of it I have checked it twice to calibration standards and it has not drifted in three years. I got it used for 60 bucks.

[TAWILDCATT]

I have B&S, Starret mics.I have digital verniers and dial verniers.I use analog mics.you right about the verniers they need to take the batteries out if not used.
Harbor tool has all linds from $5 up.4"digital for $15.they work and they are same as Lyman and RCBS.the analog take the errors out.direct reading.:coffee:[smilie=1:

[montana_charlie]

Well, I listened to everybody, but waited until I had actually found (bought) a mic to add anything.

It seems that nobody really thinks electronic mics are inaccurate (all things considered), they just don't like the idea of run down batteries. Well, even a dead electronic mic has the same numbers on the thimble...for reading it the old-fasioned way.

Anyway, I got a good price on a Mitutoyo 293-301 model. It has a frame that is different from most other Mitutoyos on eBay, so it takes three short, cylindrical batteries...instead of the 'coin-shaped' style.

I intend to build a full-length 'dummy battery' of non-conductive material, that has the necessary contact points on the ends...then install a jack to supply 4.5 vdc from a wall wart, via power line.
That should cure the unexpected dead battery problem.

When I do need it to be portable, just pull out the dummy and replace with real batteries.

While I wait for it to arrive from the great eBay store in the sky, I will be looking for really, really, really THIN things to measure...

CM