Micrometer, super tight, take it apart?
- Thread starter Mark914
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woody 73
Well-known member
I bet the oil turned to gunk from old age making it to hard to turn looks like you need to soak that tool overnight into something like WD-40 maybe that will do the trick.
woody 73
Well-known member
Darn you beat me to it by 60 seconds...
Hafen_Kafer
Well-known member
if the collet nut is tight, (mic dropped on it's head) it's pretty much a goner. Best of luck. I killed a 4 inch starret not two weeks ago.
Just back the thimble all the way off. It will pull apart after it is unthreaded all the way. Don't worry, there are no parts to fall out. Put a drop of light oil on the threads and put it back together. You can adjust the tension on the collet nut while you have it apart.
Don't soak it in WD40, that **** gets gummy and will make the problem worse after a while.
Greyson
Don't soak it in WD40, that **** gets gummy and will make the problem worse after a while.
Greyson
ttpete
Well-known member
I've had older ones do that because the oil got gummy. Get it apart and clean it up with something like brake cleaner or naphtha (Coleman fuel), then lubricate with a very light oil. I like Hoppe's gun oil.
Dave455
Well-known member
Most Starrett Mic's are adjustable!
Unscrew the thimble all the way and it will reveal a screw collar that you adjust with the small wrench provided! Back it off half a turn, clean off any old oil while you are at it and re lube, and there you go!
Unscrew the thimble all the way and it will reveal a screw collar that you adjust with the small wrench provided! Back it off half a turn, clean off any old oil while you are at it and re lube, and there you go!
PBCampbell
Well-known member
Most Micrometers have a locking mechanism for the thimble, make sure that's disengaged before turning.
the wd40 is to help get it loose. Once that is done, then clean off wd40 with brake cleaner. Add a few drops of 3-in-1 lubricant on the thread afterward.
macgyver37
Well-known member
Do you have a standard for it? You will probably want to check its calibration to the standard since you don't know it's history and whether you moved it while loosening it up.
ttpete
Well-known member
A 1 inch doesn't need a standard. It's just set to zero when it's closed.
cleek
Member
If it is just hardened oil from sitting around, I would put it in an oven and bake it. Say 300 degrees, 20 minutes.
ganymede
Well-known member
That's good for checking at the beginning of its range of motion.
If he's going to be using it throughout its range then he should check it with some1/4, 1/2, 3/4 and 1" gage blocks too.
If there's a bit of error then it should be set on a 1/2" block.
If theres a lot of error then the mic needs servicing or is worn out.
ttpete
Well-known member
OP said it appears to be mint and in box. If it was loose and sloppy, I'd agree with you. I've personally had two new mics that were in a similar state. Once they were cleaned and lubed, they were fine.
ganymede
Well-known member
Hi - first time posting here. Always appreciate knowledge on forums.
I have an ebay Starrett 4-5 in micrometer - was very sticky, gummed up, so I searched, ended up here. I thought the small thumbscrew should slip (learned it's the ratchet). Found here that it's ok to take thimble off all the way... Saw the slip ring that can be tightened - wanted to clean it all first because oil/grease is gunked up.
Filled up thimble with brake cleaner, let it soak a minute or so. Still holding it upright, I stuck a pipe cleaner into the brake cleaner between shaft and thimble housing, and "unscrewed it" so pipe cleaner got in threads of shaft. Removed slip ring, then used brake cleaner on a Q-tip to clean female threads in micrometer. Cleaned the slip ring. Put some sewing machine oil on end of male threads and in female threads, held micrometer with thimble down (so oil would run down threads) and screwed thimble back and forth all the way a couple times. Then pulled the small screw from the ratchet knob and cleaned all parts - it was completely stuck. Now ratchet works like it should (ratchet CW, lock CCW) and the micrometer works with the ratchet from 0.000 to ~0.450 and from ~0.850 to 1.000+ - it might work loose. I probably could have spent more time with the pipe cleaner/solvent. But now works well enough to measure pistons and bearing journals without high risk of scratching them.
I have an ebay Starrett 4-5 in micrometer - was very sticky, gummed up, so I searched, ended up here. I thought the small thumbscrew should slip (learned it's the ratchet). Found here that it's ok to take thimble off all the way... Saw the slip ring that can be tightened - wanted to clean it all first because oil/grease is gunked up.
Filled up thimble with brake cleaner, let it soak a minute or so. Still holding it upright, I stuck a pipe cleaner into the brake cleaner between shaft and thimble housing, and "unscrewed it" so pipe cleaner got in threads of shaft. Removed slip ring, then used brake cleaner on a Q-tip to clean female threads in micrometer. Cleaned the slip ring. Put some sewing machine oil on end of male threads and in female threads, held micrometer with thimble down (so oil would run down threads) and screwed thimble back and forth all the way a couple times. Then pulled the small screw from the ratchet knob and cleaned all parts - it was completely stuck. Now ratchet works like it should (ratchet CW, lock CCW) and the micrometer works with the ratchet from 0.000 to ~0.450 and from ~0.850 to 1.000+ - it might work loose. I probably could have spent more time with the pipe cleaner/solvent. But now works well enough to measure pistons and bearing journals without high risk of scratching them.
Jim Johnstone
Well-known member
All good advice here, I would add when you put it back together you want a very thin oil, 3 in 1 is too thick for my liking. I would either use Starrett micrometer oil or a good substitute is sewing machine oil.
pendragon1998
Well-known member
Something like breakfree CLP would probably be a good oil too.
Thanks for info. I came back here to say after sitting a couple/few hours, it's smooth through full range.
I call anything in "that kind of can", 3-in-1 (I do remember the real stuff was kind of thick). Mom had Pfaff oil in same type can. Just read label and I have Gunk Super Oil #L10-03 (old from appearance and $1.19 sticker on can) - it seems thinner than 3-1.
The micrometer is in a 224 Set A box (2" - 6"). It has 4 screw on "compensation anvils" and 4 rods (2",3",4",5"). I have Mitutoyo blocks in larger increments .625, .100, .125, .200, .250, .300, .500, 1.000, 2.000.
With the +1" anvil, 4" rod (set up klugely as shown..), and up to 1.000" blocks, if I "ease" the thimble/anvil to the block, it comes out right on (or within a line width). If I switch to a 3" rod to use the 2" block, it comes out about the same (needs more effort to get rod/block lined up). If I continue until the ratchet slips (more like a slip clutch), it goes past about .00025 or .00033". This may be okay, but does it indicate more work is needed - like tighten the slip ring or oil the ratchet?
... I did both. Tightening slip ring made it hang up again between 5 and 9, worked thimble end to end, etc, and now 1/8 to 1/4 turn of slip ring will go from "ratchet always slips" to "no resistance at all". I suppose it just needs to be used now... is how I remember a good micrometer should work, though never used one this big.
I call anything in "that kind of can", 3-in-1 (I do remember the real stuff was kind of thick). Mom had Pfaff oil in same type can. Just read label and I have Gunk Super Oil #L10-03 (old from appearance and $1.19 sticker on can) - it seems thinner than 3-1.
The micrometer is in a 224 Set A box (2" - 6"). It has 4 screw on "compensation anvils" and 4 rods (2",3",4",5"). I have Mitutoyo blocks in larger increments .625, .100, .125, .200, .250, .300, .500, 1.000, 2.000.
With the +1" anvil, 4" rod (set up klugely as shown..), and up to 1.000" blocks, if I "ease" the thimble/anvil to the block, it comes out right on (or within a line width). If I switch to a 3" rod to use the 2" block, it comes out about the same (needs more effort to get rod/block lined up). If I continue until the ratchet slips (more like a slip clutch), it goes past about .00025 or .00033". This may be okay, but does it indicate more work is needed - like tighten the slip ring or oil the ratchet?
... I did both. Tightening slip ring made it hang up again between 5 and 9, worked thimble end to end, etc, and now 1/8 to 1/4 turn of slip ring will go from "ratchet always slips" to "no resistance at all". I suppose it just needs to be used now... is how I remember a good micrometer should work, though never used one this big.
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Good advice... the 20-24 thimble markings are lighter than before.
I was glad my fingers weren't black and sticky with frame paint, but I didn't think about the markings.
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