Mitutoyo Dial Caliper

[wv109323]

I have owned this caliper for 25 years or so. The needle on the dial once zeroed at the six o'clock position . For some reason it no longer does. It is now at the five o'clock position. It seems that the dial is off about .020. I can rotate the dial where the zero is at five o'clock but I would like to have it the way it was. Can the caliper be calibrated and how?

[cwheel]

First off, which version do you have ?? The skipping your talking about leads me to believe that you have the old style with a rack gear along the beam. If that is the case, first clean that long rack gear well, get all of the stuff out of the gear teeth, that is what is causing it to loose the zero, something stuck in a tooth. Once that is done, you should have a small brass tool in the caliper box that is used to adjust the zero. With the older style, just place this tool in-between that gear and the gear on the slider causing it to skip to the proper tooth to get the zero. If it is of the next newer generation, remove the screw on the dial lock. Insert the small tool into the small space that is covered by the lock screw and bracket and adjust in the same manner. These older analog style calipers don't like dirt much and need to be kept clean. Canned air works well for these, make sure to blow it out and wipe everything down clean first before doing the above. Keep these older ones in the case when not in use. ( to keep the dirt out )
Chris

[GRUMPA]

It jumped a gear tooth, most likely cause, it had a piece of dirt stuck when it was moved. Yes it can be zero'd with a little work that requires it to be taken apart, cleaned and reassembled and lubed. Done that little repair many, many times in the past. Just have to be sure the screw heads at the end that hold the stop bar are in good shape, otherwise it's a PITA to do.

[cwheel]

Be sure and NOT to take it apart as mentioned above, not necessary with the zero adjust tool that should be in the case. If the tool isn't in the case, make one. I have both new and old versions and will post pics of each if necessary to copy. Disassembly a huge waste of time, Mitutoyo provided that tool for just this reason,
Chris

[Tamitch]

As an older toolmaker I've seen this happen on many mic's and calipers. They way I cleaned them is to get a CLEAN piece of paper and drag it through the jaws firmly. You may have to do this more than once to get them clean. I always used a clean piece of chamois to do the final cleaning. But they are clean find someplace to keep them that way, like the box they came in.
Terry Mitchell
Danville, IL.

[MTtimberline]

I have the same problem with my Starrett. I cleaned the rack and believe it was a small piece of corn cob media that was cause of jumping a tooth. I got it close to the 12 o'clock position but it isn't perfect and always bothers me.

[6bg6ga]

As a prior plant inspector I had to zero calipers from fellow workers as well as my own occasionally. Keeping the track free of grit, dust, and metal bits is needed in order to be able to both zero your caliper and have zero in the correct position. I have lived with my little zeroing tool being lost for years and it works fine. If you have to make sure the track is clean and the jaws don't have anything between them and simply rotate the dial until it shows zero. The caliper will read just fine.

[w5pv]

You can use the same procedure on Starret and Mitutoyo as cwheel described if you have lost the little tool you can make one out of .002 or .003 shim stock,feeler gage.

[EDG]

Yeah the little feeler guage tool works fine and you can get it zeroed back to 12 oclock where it is supposed to be.
Those light flaky aluminum shavings are good for causing the pinion to jump a tooth.