My caliper is showing off zero a bit often; new one or fix?

[K22]

To answer your questions, it is a Mitutoyo Absolute AOS Digimatic, model CD-6" ASX; it measures in 5 tenths of a thousandth, which is why recently sometimes when I check the zero, instead of .0000 it reads .0005. I changed the battery 2 weeks ago and clean/wipe the jaws with microfiber frequently throughout use to be sure I'm getting a correct reading. In earlier weeks/months I don't recall it reading .0005 when checking the zero; it read .0000.

Do you really need to measure to .0005"?

Join us dinosaurs, get a dial caliper, no batteries, no electronic drift. Go simple and be happy. My two always return to zero if I keep them clean. They check out with lengths standards also within my range of use.

 

[BoydAllen]

I prefer dial calipers. I have done several things to mine on an as needed basis. I have adjusted the tiny gibb screws to give parallel jaw contact, and better fit between the sliding jaw and the part that it slides on. On occasion I have cleaned the rack to remove small debris. The ones that I take to the range in my loading kit were very inexpensive years ago. They are properly adjusted and plenty accurate for the use that they get. Once they got dropped and I did not immediately notice that they must have landed on the tips of their jaws, but eventually I noticed the damage, and lightly stoned the jaws to remove the burrs. I hasten to add that all my calipers get used for is reloading, and for things like measuring bullets I have a decent 1" mic. that reads to .0001. One thing that I am lucky to have is a couple of gauge blocks that a fellow gave me. They had gone out of spec because of slight corrosion. He polished them and measured them with his shop's reference mic, and labeled them to beyond what my tools can confirm. Every so often I get them out and measure them with all of my calipers and 1" mics. Years ago, in a college machine shop class the instructor did an excellent job of explaining micrometers and how they are adjusted. If I feel the need, I can still do that.

 

[nwmnbowhunter]

Mine needed new battery. Just be sure you get the kind specific for calipers.... it measures "consistently" until battery is near end of life

 

[butchlambert]

Well, If I need a very close measurement I use my Micrometers. To me that is when I need an exact measurement closer than .005"

 

[Rocketvapor]

Measuring Brass Length (6.5 or .308) with a Micrometer can be hit or miss with 1/4" anvils.
I still like the iGaging Speed mic, but not for brass length, or things with holes

 

[Herzo]

A typical caliper will measure 0-6", you'll need 6 different micrometers to cover that range. The mics will be more accurate of course, and expensive.

0 to 1" mics will cover any precision needs for the handloader. Calipers come into play for less critical measurements. I have never relied on calipers (dial or electronic) for a measurement closer than +/-0.002". Verniers are another story.

 

[Cassidy]

I've had technical difficulty posting this multiple times earlier but will try again.

On reflection, I remember that the caliper fell to the floor (stone) about a month or so ago, though at the time I didn't see a zeroing problem. I changed the battery 2 weeks ago because of the zeroing problem but that didn't help. So I think the fall damaged the caliper. I plan to get a replacement; same Mitutoyo model. Thank you all for your comments!

 

[L.Sherm]

The O.P was talking. 0005 not .005 Butch.

 

[Chris Edmondson]

0 to 1" mics will cover any precision needs for the handloader. Calipers come into play for less critical measurements. I have never relied on calipers (dial or electronic) for a measurement closer than +/-0.002". Verniers are another story.

I use micrometers when it comes to radial dimension, like neck diameter, neck wall thickness and such. When it comes to axial dimensions like case headspace, seating depth and such, commonly available adapters and jigs are designed around calipers for good reason. Both instruments have their place on my reloading bench.

 

[rlporter507]

My guess has been mentioned, both of them. Battery low will affect this, and the correct battery needs to be used. I get mitytoyo battery's from grainer, Mituyoyo brand. just because the number on the battery is the same, cheap china batterys are not the same voltage. I read about this somewhere, maybe on the fake mituoyo u-tube video,s but there is a difference in the china and japan batterys. they mentioned the wrong voltage makes them read off. Or maybe it was the amps, i forget.
My caliper returns to zero, and i have a perfect inch to check it with, and its dead on all the time. If its not the battery, then it needs repair. there is a difference between a LR44 and a SR44.

 

[Cloudrepair]

With any calliper you need to learn the force it takes to read clearly.
Even the best can fluctuat in measurement that close but they arent really able to measure that tight
if you can get consistent measurements to a thoughsanth then it is fine that half thousand movement is not worth worrieing about if you want that tight of a measurement then use a good micrometer.

 

[Cloudrepair]

I have checks i use regularly like my gauge blocks and standards with holes i use my various ring gauges to check my measurement with my calipers to make sure my measurement is consistent and that is all about force used to achieve the right measurement.

 

[Alex Wheeler]

To get the best accuracy squeeze the jaws onto the part, dont use the thumb wheel thingy. Takes force out of the equation.

 

[dgeesaman]

I chuckle when I read comments about calipers not being good past .005” - does that mean you check shoulder bump or bullet seating depth of every round using a micrometer? But we dont hesitate to say we are controlling those to the .001”.

The reality is in the middle of this, I find. My Mitutoyo calipers* always give good readings to the .001” and the .0005” is usually right. Now if it isn’t zeroing to the .0005 I wouldn’t get too excited because the variance and flexibility in the piece I’m trying to measure is usually at least as much of a factor. But I would monitor that closely and check it against a gauge block regularly if that continued. Losing a touch of zero is not a problem but losing linearity definitely is.

* Where did you buy your Mitutoyos? There are a lot of good looking knockoffs on eBay and Amazon. I buy mine from actual metrology shops like MSI Viking and their prices are very good. Grainger MSC and McMaster Carr only sell legit copies but they are expensive. (I almost shed tears the other day when I saw a 3-pc set of micrometers arrive at work from McMaster Carr).

 

[akajun]

Caliper jaws get dirty, especially measuring brass. Squeeze the jaw between a piece of clean notebook paper and pull it out a few times. There’s probably a buildup on the jaws.
Also make sure you’re squeezing the jaws together with your fingers and not using the thumb wheel . Lastly, the warmth of your hands after handling is prob changing the zero

Lastly, they’re calipers and you’re measuring brass, get it within .001-2 +|~
If you want accurate .0005 measurement get a pair of white cotton gloves and a micrometer

 

[Rocketvapor]

For lengths greater than 1", like case length, Headspace, CBTO with adapter, you can buy a complete set of mics (up to 6" should cover your needs).
OR
A Dial caliper and a cheap 88 piece set of blocks.
The weak link in reloading measurements over one inch is the product (brass/loaded rounds).

 

[butchlambert]

The O.P was talking. 0005 not .005 Butch.

I wasn't referring to the OP. I was just relating my own personal limitations.
Yes, I have a set of gauge blocks to check my measuring devices as well as about 150 Deltronic pins in .0001" increments for chambering. I worked as a machinist for several years before being in the car repair business. I've had my machine shop for over 25 yrs, but I do know my limitations!

 

[skeeljc]

Get a Mitutoyo and forget checking the zero. Mine is twenty-five years old and it is never off zero. I just pick it up and turn it on and measure. I just wish it had auto shut off.

 

[Fuj]

Being a retired tool maker for over 40 years, and add 10 more since
then, with still doing it at my pleasure, I'll say this......Get a 100 thou
large face, sweep dial. Seeing .0005 is real easy for me. Many years
ago, I was at an auction and seen a lonely NSK (japan) 8" large dial
that had a clip on magnifier. I won the bid, and they have been on the
loading bench ever since. Magnifier was put away for maybe one day.

 

[L.Sherm]

I wasn't referring to the OP. I was just relating my own personal limitations.
Yes, I have a set of gauge blocks to check my measuring devices as well as about 150 Deltronic pins in .0001" increments for chambering. I worked as a machinist for several years before being in the car repair business. I've had my machine shop for over 25 yrs, but I do know my limitations!

I also use my deltronic pins as guages.