Starrett No. 120A Dial Calipers: Disassembly, Cleaning and Reassembly
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- เผยแพร่เมื่อ 29 ก.ย. 2024
- This is a pretty simple do-it-yourself project to help tune up these calipers - cleaning the gunk out of them when they get dirty. I also discuss how to reset the dial so that it is pointing straight up - when these get dirty, sometimes the gear will jump a tooth on the rack and the dial will not zero out with it pointing up.
Dropped my 102 today and knocked it off zero. found your vid.. Thanks a ton for making this.I was about to send it back to Starrett. You saved me many days and I'm sure several dollars.
Thanks again..
Awesome tutorial. Thank you so very much!
This is a fantastic tutorial on how to keep your caliper running smoothly. We appreciate you taking the time to share your knowledge. Great job!
+lsstarrett I worked with your tools alot and made plenty of calls to your customer service people and have always received awesome help from them... so thanks
What do you need to do if there are no screws?
@@Jimthefurryworm Paul at Starrett is a great guy, I just ordered a new part for my 120A Calipers !!!
@@edgarmilson8686You’re up the creek without a paddle.
Thanks Keith, I might try getting my fathers calipers back to zero now. meanwhile, I have a starrett 436 micrometre which needs a bit of attention.
Very informative
Cleaned my Starrett 120 yesterday and it now works like new. When I opened it up I was surprised at the amount of dirt and junk I cleaned out. I have some Starrett oil. Should the rack get a drop of two?
Thanks. My 120 is now perfect, and the indicator is pointing straight up. The cloth idea is a game changer for me.
Thank's, I need to go clean my calipers... I think you'd really like a Mitutoyo 505-673, they have a covered rack and a little key to quickly set the needle to 12 o'clock. They're very nice.
Keith, I also prefer to use dial type caliber, and I also use 2 of the starrett 128's. I clean them every so often and I find a tooth brush works quite well to make sure the rack and pinion are clean. Thanks for sharing. Job well done.
In my 15 years in the machine shop at The Grass Valley Group. I was taught that you could keep your JAW FACES clean and polished by using high quality paper. By GRASPING THE paper and sliding it out of the jaws... And to use Tri-Flow teflon spray lube, similar to REMOIL after cleaning. Dries and leaves a lubed film... My old boss sent my 120 6" set BACK TO STARRETT for service, after 40 years they needed help neither of us had to give.
Hi Keith,
Had to comment again, I had a friend stop by the shop today with a 6" Mitutoyo caliper that was a tooth off!
I showed him your video and let him clean and fix it himself!
Thanks again!
Jeff
Keith, Thanks for the video on dial calipers. I was afraid to take mine apart to re-zero them. I went to an instrument repair shop and they wanted 40 dollars to do what you did. Keep up the good work, your videos are always educational and fun.
Thank you for the valuable information, Keith! I don't own any Starrett calipers right now, but will start looking on E-bay and Craig's List. I too like the dial as opposed to the electronic units. You never have a battery do dead on dial calipers! With the $50 you saved by doing the job yourself, you can take your wife out to dinner! :-)
Regards,
Dave
Just be careful, I bought a 9” Starrett 120 dial caliper that was described as “good.” I won the auction for $60.00, it arrived, a tail piece was missing, the tension leaf spring inside the head was missing, and the gear train inside the dial was stripped. I considered fixing it myself, but parts were not for sale. I ended up sending it back to Athol, MA for estimated costs and was quoted about $100. I wanted a replacement plastic case, but this was a vintage caliper that did not fit current cases; they quoted me $15 for a wooden case, which I opted for. The caliper came back in new condition, they even ground off the previous owners name from the back of the head, and the case is like a piece of fine furniture. Bottom line is I ended up with a perfect caliper worth over $200.00 for about $175.00 so I think I did alright. Yes, the eBay seller got a negative review.
Excellent video, thank you Keith. It's good to see what can fall out before I take mine to bits ;-)
Hi Keith, I'm sure there will be some throwing their hands in the air at using Q tips as they are prone to leaving fibres on any sharp edge. I prefer to clean the rack and gear with a soft-ish tooth brush, but I'm sure there are also some hand throwing at that too.
Mitutoyo calipers are much easier to reset to zero with the little tool they provide, it fits in a small hole and allows you to disengage the rack without any need to disassemble anything save the hole's cover, which also acts as the bezel clamp.
ATB
chris
Nice demo, Keith! Will help a lot of people out!
Thanks!
Jeff
Another great video on a valuable topic... THANKS! Sometimes it just takes watching someone else do it to encourage you to DIY...
after 50 years I have a box full of these. Never knew we could adjust the rack. Digital are ok, they can do things dials can't. It took a young kid to show the old man modern technology tricks. still learning thanks good work
Thank you. I couldn't figure out the spring clip and plastic strip orientation until I watched your video. The rack adjustment is awesome to get that last couple thousandths of an inch.
Thanks Keith! I just finished cleaning a Starrett 120 along with your video. I thought I was gonna have to throw it away. I have a bunch of measuring equipment that needs maintainance. I bought my wife's uncle's machine shop lock, stock and barrel last year. They had been running this place since they got back from the Pacific in WW2. The last brother had to hang it up about 5 years ago. This place is a museum itself. I am still using an old Sydney lathe, 1894 Brown and Sharpe horizontal mill and a Champion 20" drill press. Although the DP needs a major overhaul.
Hi Keith. I got some dust in the gear rack of my late 1970s vintage 120-06 dial caliper. The dust made my gear jump a tooth so my 0" with jaws closed was 0.025" off. I opened the dial to expose the gear, cleaned the rack, closed it up. Now the needle points north but not directly at 12 o'clock. Upon reassembling I found a tiny "L" shaped part and I wasn't sure where it went. I figured it was part of the bezel locking assembly and put it there. Did I guess correctly or is that little part supposed to go elsewhere? Thanks!
My big pair of SPI's could benefit from this. I may head out and get them now and get started!
Dude... Thank you!.... I bought a pair off eBay that were advertised as new and when I got them I could see they were clearly not. I kept getting anywhere from .001-.004 in variance every time I tried to repeat zero. I called starrett and was about to send them in for repair/ cleaning for $78 but then I found your video. They were exceptionally dirty on the inside, but since cleaning them up they look new and stop dead on zero every time.... THANK YOU!.... Your video was not only very helpful, but extremely professional- outstanding channel.
Totally agree. Very professional. Great job.
Hi Kieth, I agree with you on dial calipers. Gone back to a fine adjust vernier and a dial caliper.
I like a dial so I can see which side the dial indicator arm to the dial face mark. Interpolation a lille plus or minus thing you cant see on a digital!
With out track cover, Starrett 120 A can be blown down the rack down away from the dial, pull the dial to right and blow to bv the left.
Now six years later than this vid, they have ckange the battery from LR44 to CR2032, which hot me to reinvest into an a new one for general use and to get a metric reference also.
Also enjoy your videos and your adventures!
Happy Holidays 🎅
Steven Columbus Michigan
Many thanks, , ,If you're still there, it's about time to buy a quality make screwdriver, Would you, or anyone know the head diameter, and slot thickness of the screws ? It looks like just under 125 thousands and just under 25 thousands
Mine's jumping the tracts just like you said. I will try and take it apart and clean it like you shown. Thanks for taking the time to do this video!
Very informative indeed. Easy for you to do, but when I do it, no caffeine .
Kenneth Bartlett lol
Thanks for taking the time to make the tutorial. I was able to fix both a zero calibration issue (out of adjustment rack) and get the springs back in properly. My 30 year old 120A's are back in service - thanks!
I purchased a 120A 6" used that is missing the crystal. Any idea where I can find a crystal?
Check in watchmakers and model suppliers catalogs such as MICROMARK.COM to find a screw sticker. These have 3 or 4 spring clips in a tube which when depressed come out of the tube and open. The clips or prongs will hold small screws or parts to make reassembly a little easier if have FAT fingers or tight places. Anyway good luck.
I have made a plywood tray about 2 feet by 3 feet for working on things such as this..The culprit in most of the dial calipers I take apart is the anti backlash gear and spring, usually an ill-defined zero is the fault..I find digital calipers irritating to use..
Thanks for this video. Got my old Starretts recalibrated. :-)
Mr. Pete Repaired a Brown and Sharp caliper, I believe it was tip 407. You remove the bezel then the face. He was able to take the face off without removing the needle. Then there's three screws under that. but only two need to come out. Hope that helps for next time. Take care.
Anybody know how to fix these when they don't always go back to zero?
My boss has about ten of them that all have the same problem in that they will vary by 1 to 3 or 4 thousandths when you close them. All of them were extremely dirty, filled with chips, oil & dirt. I took them all apart this far and cleaned them to perfection, even took the rack off & cleaned all the teeth but the needles still land in different spots. Some seem to do fine if you close them softly but they will still be off once in a while. I haven't gone any further because I can't find any instructionals for the 120A and I don't want to pry on stuff until I know, for sure, how to further disassemble them.
Like an idiot it finally happened and mine fell which knocked the dial from zero to roughly 40 thousandths off. The rack on mine does not have screws and I am unable to reassembly with the dial at zero. Any ideas on how to fix? Thanks!
Keith, I've cleaned my rack and pinion, but now I need to disassemble the dial part, the additional gears inside are also gummed up, but I can't figure out how that's done ???
I just cleaned up & zeroed a $60 E-Bay find. As good as new, Thank You Keith.
Some small tweezers would not go amiss here!
I recall seeing a very small piece of spring steel that you would insert into the rack to jump the pinion back in place. I don't recall the manufacturer of the caliper, that was about 40 years ago.
I like to save my old worn nylon toothbrushes for cleaning tasks like that. They're stiffer than q-tips and don't snag or leave lint, but they're still soft and won't damage instruments.
great timing spotting this video as one of my hf beater calipers is playing up after 15 or so years of accumulated abuse. will be attacking it soon.
could you now do a video about sticky micrometers? i have a couple that the spindle is very stiff to turn making them virtually unusable. there are plenty of videos about calibrating a mic, but I've not found one about cleaning a repair.
Hi Keith, for some time I have been using the digital calipers, but your video got me interested in my dial calipers. While fixing a computer and while watching your video about how to clean them, I took out my Mitutoyo 6 inch caliper. It looked very easy to take apart and it came apart very easy. I have mostly very small tools for 1/32 live steam engines and this looked like any easy project. It did not go back together very easy and I would not recommend taking one of these apart. The small gear and pointer came lose. There is not much keeping it in place once it is apart. It is kept in position by a small metal yoke spring working against the rack and the dial under the bezel. The only way to put it back together is to remove the bezel. And with luck I did get it back together. It is now clean but I did not get the pointer to be in the 12 o clock position. I am just happy I did get it back together. I do like your videos and enjoy learning from each one. I think the Starrett ones are great and the way to go. Most of my tools are all used.
Man, That was well timed. I picked up a set of 120 12" used a week ago that were a little sticky until this morning. Thanks a bunch. A few minutes with a toothbrush alcohol and a touch on the "bad spots" with a copper pot scrubber and they look like new. I think I owe you a cold drink for this tip!
My mitutoyo 4" needs this done but supposedly there's a thin wire that comes with them new that you slip in behind? I don't have the wire or know how, if you know how I'd love to see it on a video, I've looked and there's not a how to video anywhere.
For those of you who still have your own teeth, an old toothbrush is an extremely handy and overlooked tool for getting tiny particles out of tiny parts, spreading grease and oil as well as being resistant to many solvent based substances.
I never throw mine away, gently heat the neck and you can angle the head any way you need and the handle can be melted or sharpened to form a surprisingly strong point, scraper or prybar (spudger) for opening anything in a casing. It's electrically insulated so good for inserting/removing watch/button batteries.
The one off my father is a 500 dollar one, mine is digital and 10 dollar, ps. Both are metric
Use denatured alcohol, less water in the mix than rubbing alcohol.
Heh, funny, mine doesn't have that plastic piece, mine has a metal strip and the holes in the caliper are threaded. Missing one screw at the moment, but it still holds.
Good idea to show this i wish my special education teacher with the nice beard (who looks like a toiletbrush) from the first years when i was 15 should see this, i had one caliper with a chip in there it rattles hard the dial and everything was ok he decided to keep it for hisself and asked the Boss for a new one !!
hey, love the video! Can you do a video about disassembling the gauge portion?
"im new" does anyone put any lube on the gears? or are they just dry?
thanks in advance!
larry
I got these from my dad when he passed. I believe someone on my line at work messed with them and dropped them. Now the dial is way shifted. Thank you
I would recommend using an ultrasonic cleaner to clean the rack if there is one available.
Great video.
The exact information i was looking for
+androidmm56 Glad to help!
I tried to do this but all the little screws be tighter than red locktite. Cant get any of them out
Hi Keith,
Personally I own a cheap digital "beate approximeter" to get close.
I like the digital cause it's easy to convert between imperial and metric, and, that beater can withstand lots of abuse, when it dies, it's under $20, I don't cry because of the money, just because I got attached to this old beater.
For more precise measures I own an assortment of Mitutoyo and Starrett, like you just say a "real machinists" really cherish his equipment.
Thanks for sharing,
Pierre
Careful. Once you take the pinion off the rack you might lose tension on your anti backlash spring. This will cause the calipers to fail at making consistent readings. Preloading the spring again may require disassembly of the dial. It’s doable but can be tedious.
I thought that too on mine, I just got done building a set of 120s, but since the gears are matched together on the same gear they don’t lose their backlash unless disassembled from the gauge itself. I did have to retention it though when I did disassemble my gauge, long process but I think I got it.
Always enjoy your how to's!
Thanks Keith.
Razor
TRY AN OLD , CLEAN ( TOOTHBRUSH ) TO CLEAN CREVICES .
Watched video on cleaning 120A Caliper. I clean mine with solvent and a fine Bristle Brush. Mine came with a tool to reset the dial without any disassembly what so ever..
Wayne Gotthardt Some of these calipers did come with a little piece to slip under the gear so that you can move it a tooth or two. Problem is, if the gear jumped a notch, it was probably because there is a piece of trash in there. When my needle moves, I just take it apart and clean it to make sure it does not happen again real soon. I just had to clean mine again the other day....
Thanks for another informative video.
Never heard "as easy as cake" always heard "as easy as pie" guess that is just a different part of the countries slang.
Have you ever cleaned a dial indicator? Have some that are 40+ years old that have some sticking places and am sure that all they need is a good cleaning.
HH
I have a Brown and Sharpe 0-1" dial indicator that I took apart not too long ago. It had some sticky spots in the travel after someone had dropped it. I worked the lens off by lightly prying with a small screwdriver. Then I was able to work the graduated outer portion of the dial off without taking off the needle. Underneath that I found four screws. Those four screws when loosened allowed me to adjust the mesh of the gears and I was able to completely eliminate the sticky spots in my indicator. A hand extractor for watch making is a wonderful tool for this job. I wish that I had one.
A couple of tips I hope you'll appreciate when working on small stuff like this.
You can keep a sheet of copier paper and cellophane tape dispenser nearby when taking out small screws. Orient the screws spacially on the paper as they are oriented on the piece you are taking apart, tape them down, label them by writing nearby on the paper. I use this technique when taking apart laptop computers. It's overkill, but I hope you'll appreciate the idea.
When dealing with putting the tiny screws back in, use a small neodymium magnet and attach it half an inch or so up the shaft of your screwdriver. Ferrous screws (most of them are) will then cling to the tip
I really enjoy watching your videos!
tiger12506 Thanks for the tips - I took a pair of these apart a couple of weeks ago and I now use a small cup to hold the tiny screws. I like the tape idea!
awesome video, now I have to behind my shed and find the ones I threw away cause I didn't know I could clean them and reset! learn something new everyday with you guys :))
two so far one was really bad it was bent
I agree, dial calipers is the way to go, and the Starrett 120A is a great caliper. I have two of them that haven't been cleaned since I've owned them, and that's many years. I've done much more lathe work then normal lately, and now my calipers need a good cleaning. Thanks for presenting this information, and I've visited your website many times.
I have a Starrett #216 Micrometer with an odometer style readout. At .016 approx. 180 degrees off of zero it clicks with a resistance and then every full rotation from that point on, it also has constant substancial resistance to rotation that is greater than the ratcheting thumb end can overcome. The lock ring is fully released. What could be wrong? Buggered thread inside? Thanks.
Great video! Two questions: Do you recommend a lubricant for the moving parts? Secondly, what is the threat size of the various set screws? One is missing on mine. Thx!
Were these American made, or are these the Chinese version? Can you tell me how many revolutions the gear on the head turns per one inch? Great video, thank you!!!
This model is American made
Never trust anything that uses batteries! 😎
Thanks Keith! My dial was off, now it's not and my calipers are clean and like new. Great video! I must admit, you had me giggling a little when you were struggling with those tiny parts.....#bigguyproblems
Great video. Thank you.
I got a 6" red-face 120a Starrett it was off 25thousands. I followed your directions and got it zeroed again, but my dialed-face is moving(loose) and the tighting pin is not keeping it tight. How can I fix this?
Do you mean the red dial is loose or the whole bezel?
No the face(red-face)is loose. The dial is at 12:00.
Hi, Love your very informative video's , and I guess it might have been the cocktail , anyways I was noticing your apron, well i guess they don't call it an apron, like what women used to wear in the kitchen, and men had the heavy duty one's for the work shop, so, what am I trying to say , if you look at you and the room you are in, looks like a kitchen, I guess us guys have been wearing APRONS, HAA HA , it just struck me as funny when I thought it, OK enough sharing, and thanks again for the greatly informative videos
I imagine an old toothbrush would do well too, just dip the bristles in the alcohol and scrub gently, since the plastic bristles are softer than the metal its made of, there's no danger of scratching it.
Superb tutorial Keith, My Ebay purchased model 120 now good as new !! Thanks Man.Needs new crystal, does the bezel just pry off on the 120 ?
This was a wonderful find as my Starrett 102A Dial Calipers skipped a gear this morning. I searched you tube and found your video. As a result I didn't have to spend $70 or so and go without them for an unknown time period. Thank you Keith for posting a very clear and concise instructional video on this topic. Dan
Thank you sir for the excellent tutorial. I dropped mine on a carpeted floor and it jumped a tooth. Now I know how to fix it myself. Love my Starrett
Great! I just got a Mitutyo 12" like that. It has the same problem and worst the dial must be fix. The needle in the indicator is loose.
Is there any way to remove the glass in order to repels
Hi Robert, the glass comes away with the ring, just gently lever it up with a flat blade screwdriver.
Chris Stephens Thanks Chris. I did that. The bad news is that the dial spindle is broken into the hand.
Alas, It's a job for the repair shop.
Alas indeed, sorry to hear that,
Thanks Keith! I always learn great stuff from your videos. I have a few calipers that belonged to my dad. I'll be looking them overt see the make and if they need to be cleaned.
Thanks keith, re-assembling these dial calipers is a real test of patience. I did an overhaul like this on my cheap japanese dial calipers. those are some tiny screws on the dial! I've been keeping vernier calipers in my pocket in the shop. mainly to get used to reading a vernier, but hey theres a lot less that can go wrong with them.
you might want to tweak the rack with the screw driver on the back end of the rack. Just in case you wear down a tooth or chip something.
Forgot to add a drop of oil to the rack. (keeps it sliding smooth)
I found once you have the gauge on zero, slightly tip the gauge top downward and it helps the gear drop in place easily and keeps it at zero, align the holes then tip it and drop it in place.
Thanks Keith. Just got a used one off Ebay that seemed jammed. Your vid fixed it.
***** Keith I have a 98-12 Starrett level and I need to change the Vial. how is the best way to do that sir ?
+Outlaw Rail removed the old vial with a small flat head screw driver by prying away the compound that secures it. the new vial should fit snug if you use the compound and smooth it out at both ends and place on a level surface while it dries
Thanks Keith! Mine has jumped a tooth, and now I know I can go in and clean/fix it.
Great video as always. Never thought about taking one of these apart :)
Nicely done! Did mine tonight during your video. Easy
Wow you saved my OCD from driving me nuts- my zero was at 3:00! It was nice to get them clean while apart too, thank you!!
Did you completely take it apart and clean it like he did? Or just the face part and clean the gear? I'm kinda worried I won't be able to put it all back together if I disassemble it like he did.
Thanks a bunch . This is a great video for what i needed
shame my mitotoyos dont come apart the same, but after taking off the end stop, i could clean it out better, at least i could remove the rack which had 20 years of grime under it
With Mitutoyo you need first to remove the dial glass and bezel.
Then pry off the indicator needle with small flat head screwdrivers (it's a good idea to attach a small piece of tape to end of the indicator needle as it tends to pop out quite forcefully). Under the free-floating bezel you have screws holding the mechanism in place. Getting it back together is bit tricky on adjustment-vise, but nothing impossible.
mikey_d
ahh i did get the bezel off but stopped at taking the indicator off, taking the plastic end stop meant i could take it off the end and remove the rack for cleaning, thanks for the info
mikey_d The beauty of Mitutoyo calipers is that you can use the provided tool, that bit of wire with a square hole at one end, to disengage the pinion from the rack so you can re-align the pointer to zero without taking anything apart.
chris
Chris Stephens
provided, maybe, but lost 25 years ago! lol , i aligned it pretty much near the top via moving the needle before i put it back on the rack, took a few attempts but its much better than it was at the 4 oclock position, if you have pics of the tool perhaps i can improvise with something
dead easy to make, I know as I have made a few as once dropped in my shed they will never be found again. I will go and measure up and post details later.
Hey Keith, I was hoping you might be able to tell me how to disassemble the dial on the caliper. The two screws on mine on the inside came loose. I certainly dont want to damage anything. Thanks
Robert Guy I probably should do a follow up video to show that. You basically have to pop the dial off of the stem that it is mounted on and then it comes apart pretty easily. A small screwdriver can be used to put upward pressure on the part of the dial that presses onto the stem to pop it loose.
Excellent video Keith thanks
Thank You. Very usefull vidio. A great help.
+Luigi Torchia My pleasure!
Great video, thanks keith
I am attending machinist school learning manual and CNC machining. I love your videos. The teacher can only teach so much. Your tips and tricks have helped me excell in my classes. I am a perfectionist and being a machinist gives me pleasure. Thank you for dedicating your time to these videos to make sure that machist isnt a dying trade
Thanks for the kind words Tim and thank you for taking the time to learn both manual as well as CNC. Having manual skills will give you a huge advantage over most of the kids coming out of programs these days that are only taught CNC.
Keith Rucker - VintageMachinery.org
what is the method for tensioning the hair spring to get good repeatability. I recently got a used 8" from SPI, and the hair spring had come loose from the gear causing it to lay over to one side and getting caught up in the other gears resulting in it locking up. I've gotten both ends of the spring back in proper location (not easy by the way) but unsure how much tension needs to be on it. I don't want to over do it and break the spring
thanks for the video.
excellent video keith
Nice tip Keith.
Thank you, mine jumped 25 mils
+leejc I hope the video helped!
I have worked in a calibration shop for almost 4 years and i never thought of using the rack for minor adjustments,,, I just used the gear that is attached to the rack which is alot harder to do, plus alot of my customers would do what ever they wanted to with them, like run over them with a truck. Anyway I really enjoyed this video and learned a little something. So thanks
+Charles Thompson also the Slider at the top along with the plastic piece, I have never seen on the Starrett pieces, Well the slider on top I have,but there was never any thing on the bottom... they must have removed it
+Charles Thompson The rack is only good for very minor adjustments, but there is some room in there to move the dial over a bit one way or the other.
+Keith Rucker - VintageMachinery.org I never messed with the rack myself. I was also wondering the best way to adjust the Depth rod? I have loosed the screw and sometimes that works, but I have seen some that are way out and workers have just placed it on a grinder and grinded the rod, but that does not seem to be the best way, we have not instructions to speak of
Charles Thompson
what is the process for properly adjusting the hair spring to get good repeatability
Make sure it is tight and lined up correctly, if not it will slip and give incorrect readings