Mitutoyo Dial Caliper Re-clocking Calibration

[@ffolkess]

Thank you for this, my dad's old Helios skipped a tooth and I read somewhere about cutting a strip from an aluminum can. I was baffled how that would help and not damage the gear, but when I saw your video, I realized the pinion is just spring loaded and saw exactly what needed to be done. 30 seconds later, it was back to zero!

[@zakm0n]

I have a 505-637-50. Small paper clip in a slot on the back of the face at 12:30 seems to lower the pinion away from the rack to allow reclocking. Didn't even know it was possible. Thanks!

[@ecstrat100]

Thanks Steve, Mine is a 505-637 and just for fun I cut a strip of soda can just to get a feel for the teeth location and when I felt it bind up I stopped. Sounds crude however I closed the caliper and it when 180 degrees from 3 o clock to 9 o clock. Tried it a second time with less presser and closed the caliper and was dead on 12 o clock. How luck did I get. Thanks for the tip. Never loosened the jib screws or anything. Now I need to inspect the rack with the stereo scope as it has a weird feel at .350 but still measures nicely. Thanks

[@nickp4793]

Nice video. You're not a tooth off though when it's off only 2-3 thou. A tooth is more like 10 thou, or 15 thou, depending if it's a .100" per rev or .200" per rev model. The way to get the last few thou is to loosen the rack screws from the backside of the caliper. Then you can slide the whole rack until you are exactly at 12:00 with the needle. Slide the rack by using the screwdriver still in the screw head, to push the rack one way or the other until it's perfect. Its super fast and easy.

[@stevewatr]

Thanks!

[@stevewatr]

@incelpolskatv3855 hard to say. If they have always been off since new, then they might have a defect that is permanent.

[@ddnuk]

Thanks! Helped me re-clock my caliper. Much appreciated.

[@AnthonyFrancisJones]

There is a very quick way to do this (though probably a bit of a bodge!) If, as with mine the screws holding the leaf spring are too tight to remove instead of a metal shim place a small piece of sellotape over a few of the teeth on the rack. Then run the pinion over it. Check the setting. A few attempts and you can get very close to a vertical zero with minimum time, kit and effort! Note, as I am sure you know, keep the rack really clean. Tiny chips of metal can get caught in the rack's teeth gaps and cause the pinion to ride up and miss teeth. Thanks for the great video!

[@chrisstephens6673]

Just a thought but on the first set you did with the strip of metal, rather than guess why not use a 1" standard from a 1-2" mic or a gauge block if you have one. I also have a video on resetting mitutoyo calipers, my most popular video by far, seems a popular subject.

[@ddb1143]

I had no thin strip at the moment when I went to adjust my old dial calipers but I did have an identification tag with small wire wraps. The very small gauge wire worked easily.

[@gbowne1]

I quite often find that the brass gib strip that's on top of the beam gets very very dirty and makes it hard to adjust properly. So I take mine out every so often to clean it with a medium hard eraser then a little Starrett tool and instrument oil will keep it operating smoothly at least for a while. I also remove the rack and toss it in the ultrasonic cleaner with some simple green. I've inherited some orpahan calipers that were given to me and they were quite gummed up so people gave up on them. You can make the brass key pretty easily. They used to sell that part separately, but for Mitutoyo items you have to go through a major distributor although I have had good luck with reaching them through their Instagram.

[@billshiff2060]

That final setting can't be 1 tooth off. That would mean the pinion has to have ~200 teeth. 1 tooth probably is what you had, .019 ~.020. which should be about 10 teeth on the pinion. Count the teeth on the rack over .200 and you'll have the number of teeth on the pinion. I'll say it has 10 teeth and each 1 tooth will put it out .020". For the small error left it has to be either the needle has slipped on it's shaft or the rack has shifted in the housing.

[@12inchrob]

Legend! Thank you 🙏😀🙌

[@williemaykit7940]

My old set of Mitutoyos were dropped and feel like they’re skipping a tooth. Just not smooth and are clocked wrong now. I tried to loosen the set screws and used the wire in the slot under the dial, but feel like I can’t push up on it at all. Mine are .100 per round, but look similar to yours. Any advice?

[@danielkaylor8395]

Where do you get a replacement cristal !

[@stevewatr]

You can get cheap generics on ebay. Search by size on millimeters. Or you can contact Mark Ratkowski at MR Tool Repair.

[@danielkaylor8395]

@@stevewatr Thank you.

[@freestyla101]

Hey do you know why the scale is in inches and centimetres? Strange to have a metric scale with an imperial dial.

[@KazeHorse]

His have imperial on the top of the rail and metric on the bottom. Seen some with both readings but the dial always represents one or the other.

[@freestyla101]

@@KazeHorse very interesting. I recently picked up an old set of these calipers with the same scale. Reads in inches but shows metric as well. I wonder what the reason for this was

[@jacencko011]

@@KazeHorse you have that reversed; metric is on the top rail. You are also mistaken about the dial always being imperial; there are some brands that have metric and imperial readings on on the dial face along with being on the rail.

[@jacencko011]

@@freestyla101 the reason is so you don’t have to have 2 dedicated calipers if you work with metric & imperial.

[@freestyla101]

@@jacencko011 Do you read the scale and use the dial as if it’s metric? Or do you just estimate using the scale and ignore the dial.

[@pcisme1813]

Thanks bro

[@platypus357]

Really not a good idea to go putting a shim strip in there to lever away the pinion gear from the rack. You risk damaging many things including the tension spring inside the clock. The easy way to do this is to pop the cover off the front and lift the needle off the pinion then push it back in at 12:00 (with the jaws closed or set against a standard).

[@b03tz]

Thanks Saul Goodman.

[@olegpetelevitch4443]

Buy another pair !

[@jacencko011]

Everything you’re doing in this video is nonsense. There is absolutely no point in making the needle stay at the 12 o’clock position. Of course you want to open and close along the whole travel to see if you’re jumping teeth but it has nothing to do with repeatability, accuracy and/or calibration. Please get at least one master pin to check for wear by rolling it from top to tips of the outside jaws, at least one gage block under 2” to check if it’s actually reading correctly (I’d suggest a square one cuz they’re better for checking the depth rod readings) and a master setting ring under 1” so you can check the inside jaws. It also literally sounds like you’re jacking up the teeth and gears by using that shim over and over again to very unsuccessfully to get the needle at 12 o’clock when all you have to do it rotate the dial and lock it.

[@nickp4793]

What are you dreaming man? The needle is supposed to be at 12:00. Whenever you find a caliper that is not, it means it's been dropped. Having it at a random position like 4:00, and rotating the bezel zero there is nonsense. Yes, that keeps the accuracy, but it makes reading them difficult. Plus, it's not professional. Tools like this are used by professionals. If someone had one clocked wrong in a tool and die shop, they'd be laughed out of the shop.

[@firstielasty1162]

Some older mitutoyo calipers came with a little strip of steel and instructions to do exactly this.