Anyone Know How to Calibrate Mitutoyo Digital Caliper?

oneskilledshooter

oneskilledshooter

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My digital mitutoyo is out. I am not asking how to zero it, I am asking how to actually calibrate it. Anyone know? It was out by .002 and I messed with the two tension screws and now it's out by .005! Eeek! Google has been no help at all. No info over at the mitutoyo website either.

I know I can send it out to be done, but I am hoping to save the cost and down time.
 
Digital calipers - wipe the jaws clean by lightly gripping on a piece of paper as you pull the paper out... then close the jaws all the way - then turn them on, hit the 'zero' button and they should set to zero. Screw adjustments are not required with digital.
 
if the 2 little screws are to loose, they will not stay square when you close them on something, and if they are to tight, you will have a hard time sliding them. I would set the screws so they slide nice and smooth but not loose enough that they will slide opened or closed by holding one end or the other and letting it slide.

There is usually another button to SET it to a hard zero, not just a reset zero, maybe you need to do that as well. And check a piece of paper, they are usually about 0.003" thick if I remember correctly.
 
There is a Mitutoyo service center here in Canada. if you can't figure out how to fix it, contact them and arrange a re-servicing. They also work on calibrating all other major brands.

Also, try replacing the battery. It may or may not help solve your issues.
 
Make sure there's no burr on the jaw tips and lightly hone if there are any, clean good, close them and check for light shining through when closed.

The Absolute button that you have to push in with something small sets your permanent/absolute zero, should be done each time a battery is changed.

As to the adjustment screws, only ever had to adjust 1 once after years of use. Hardest part was getting the little screws to move, pretty sure they thread lock them a bit. Then it was just a matter of snugging it up a bit, front screw will tighten up the tips of the outside jaw, rear one the other way. I don't know if there's other adjustment screws on the underside hidden under the plastic cover, never had to dig that far into one yet.

Check measurement at the tips and at the top part of the jaws, ideally with a gauge block or 1" standard from a micrometer, gauge pin or whatever that's accurate anyway.
 
I'll have to check when I get home in a few days but if I remember correctly (and this is assuming you have the Mitutoyo Absolute), there is a tiny little 'reset' hole either in the battery compartment or behind the rear panel. If it's not where the battery is, you'll have to peel the rear foil panel back a bit (I want to say it's in the bottom left corner - opposite side of the battery). With the jaws closed, use a needle, pin, paper clip, etc. to press and hold the button for a few seconds with the unit on.

As has already been stated, square up your jaws first and get your gibb set right, then calibrate. Confirm with a one inch standard and also a longer one (4" or so if you have).

Hope this helps!
Rooster
 
I've been a machinist for 20 years and have never heard of such a silly thing, close The jaws and if it is out zero it, vernier is just a ruff measuring tool, I don't use it for .001 tolerances anyway
 
As others have said, make sure everything is snug, but free to move, clean the jaws, set your zero. They are just guestimators anyway, akin to a 6" pocket scale.

Check they are at zero when closed, then measure a known instrument such as a gage block, if they are way out, send them back to be repaired.
 
I think what the OP has discovered is that his calipers fail to return to zero (and are out by .002 or .005 now) when he measures something and then closes the jaws again. You set zero, measure, return and it's not zero ... this is a problem. Yes, they're not micrometers, but Mitutoyo Calipers costing a couple of hundred bucks are pretty close. Mine (newish) are wonderful. Always zero after a measurement. Mine are the Absolute Coolant Proof model. So much happiness in a plastic box!

The only digital calipers I had failing to return to zero were Crappy Tire ones (sale: 9 bucks) and the calibration method was simple: toss. These are the calipers recognized and preferred by CFC, by the way. I met some resistance explaining I had better ones. Apparently RCMP's budget doesn't extend to Mitutoyo.

Sorry, calibration and repair is the dominion of those who charge the large. I have never heard of any method to recalibrate calipers, other than to clean the heck out of them and replace the battery, neither of which are likely to help you with your problem. Off to the manufacturer! I keep a spare (Mitutoyo) caliper just for that sad moment. Only one digital micrometer, but two calipers. I figure my first set will never fail if I have a spare, and so far, so good!
 
I recently started a new job and had to have all of my tools calibrated. I had a 0-3 set of CHEAP Chinese mics, plunger indicator, and a test indicator that are well used. They passed calibration with flying colours. My 6" Starrett caliper and mitutoyo .004/.0001 test indicator, did not. Big name doesn't always mean better, it depends on how the tools have been treated throughout their life.

My suggestion would be to CLEAN your caliper. I've had digis start to screw up and not repeat when they got dirty with coolant or oil. I would have given them a good clean with some contact cleaner on a q tip before adjusting the screws. Give them a good clean, and readjust so that they read 1.000^0 on a 1" standard, then as suggested test them on 2", 3", 4", etc. Test all the way to its limits. If you don't have standards out to 6 or 8 inches, whatever the caliper size is, you can use other objects of a known size, such as setting rings for inside mics, or just pieces of rod that have been measured with a known good tool.
 
I mentioned this topic in the lunch room at work today, not one of the machinists there ever heard of calibrating a vernier, and between the 6 of us have about 150 years in the trade, we actually had a good laugh
 
SND said:
The funny part is a digital caliper is not a vernier.

:D
Click to expand...

I was thinking this as well but I figured, what's the point?

Thing about the scale on the Mitutoyos (I don't know - maybe I'm thinking about an older model) is it's exactly that - a scale. Have none of you had to set (dare I say calibrate?) a readout scale on a machine? Same idea. The scale doesn't just magically know where zero is.
 
The original poster seems to be ignoring this thread...

...anyway there is no way to calibrate a digital caliper. You set zero on closed clean jaws and it reads how it reads as you open the jaws... there is no point down the 'scale' where you can calibrate it... period.

No different with a dial caliper or a vernier.
 
You need to ensure the jaws are square by closing them and adjusting the gib screws on top until the gap of light between the closed jaws equalizes. Tighten the one closest to the jaws while allowing slack on the back scew to bring the tips together, the reverse to do the inverse. This will get you close.
Then measure a gauge pin or drill shank at the jaw tips then the jaw base, adjust acordingly.
 
My Question - Accuracy of lower quality digital calipers? (I prefer digital readouts)

I know this is an older thread but my question is in reference to Digital calipers and micrometers and some of you sounds like you have had extensive experience with them.
Im not a machinist, nor am I shooting in competitions .. yet, and I dont have OCD ....... although Im told Im ADHD ... which means my attention span for nitpicky things isnt great! LOL

I have a set of Mastercraft and Frankford Digital calipers. For the most part I get similar readings from both although it could be .001 difference based upon amount of snugness I apply (yes its my own word - snugness)
If I purchased the Mitutoyo digital calipers would I notice much difference in my measurements?

I also have a Sinclair digital thickness gauge http://www.sinclairintl.com/reloadi...meters/digital-thickness-gauge-prod36561.aspx
for measuring the inside of my case necks as I felt that I could not justify the cost of an inside digital micrometer that would not get used regularly.

Has anyone used this one from Sinclairs and compared it to higher quality micrometers? IF so what are your thoughts.
 
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