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Starrett micrometer fix

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mwestcott

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#1
I found what I thought was a great deal on a little used Starrett T230RL 1" micrometer. It had some old gunk on it, so I thought that was why the spindle was sticky when turned. I took the spindle out, cleaned and degreased everything, and it is still so tight I can't use the ratchet.

Upon looking at it, it appears the spindle lock mechanism isn't retracting enough and is dragging on the spindle. It will turn to a stop and lock the spindle, but it will spin all the way around the other way and release a bit, but not enough for the mic to spin freely. I found a bit of info on line, and several mentioned that, when the thing is apart, DON'T turn the spindle lock. I'm sure I did when cleaning it. Nothing I can find mentioned how to fix this issue.

It may be related, but it's off zero by about .0005, and I tried to rotate the barrel with the spanner, and it won't budge. Thanks for any advice!
 

Tony Wells

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#2
It's been a while since I serviced a RL series, but it seems to me there is a small pin involved in a split portion of that lock ring. If the split gets distorted by turning it when you shouldn't, the open position still doesn't "relax" the friction on the spindle. You could buy another lock ring, but no harm in trying to bring it back to proper shape. If you can't, then maybe look at buying a replacement. Or a quick call to Starrett may result in a "how to" on fixing it. I'm not absolutely positive about this., As I said, it's been a long time since I had one apart and I may be confusing it with another instrument. I have that style lock on my 0-6 set, and a few others and strongly prefer it.

Oh, and the cal error is not related.
 

mwestcott

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#3
Yes, there's what appears to be a split ring in there that isn't moving out of the way. No idea how to get it or the lock ring out. There is a very small notch just in front of the ring on the barrel that I bet has something to do with it.
 

mwestcott

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#5
Thanks, I've tried that already - I get the message "the page you are looking for doesn't exist", with direction to a couple of links that go to some software company. I did find some information on another site that described my exact problem. The lock ring was moved when the spindle was out, which bends the split ring in there, which has a pin and cam arrangement. With the spindle out, the lock ring is supposed to slide out of its groove, and the split rings can be adjusted. Of course, my lock ring won't come out. I suppose the split ring was bent enough it has it locked in there. Any more force than I'm using, or going after it with a tool, will likely cause major damage.
 
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f350ca

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#6
When you figure it out post the solution PLEASE.
Someone posted a how its made video on Starret micrometers, SO I like a kid had to see the ground thread. Looks nice but when I went to reassemble it I have your problem exactly.
I've had them apart before to oil the threads on some old ones that had sat for decades and they went back together with no problems.

Greg
 

Tony Wells

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#7
I'll be in the shop tomorrow. I'll take one of mine apart and report back. I've done several, but it's probably been 20 years. It will come back to me.
 

mwestcott

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#8
SUCCESS! I was able to resolve this problem. The lock ring and the split ring do indeed come out directly upward, after removing the spindle. There is a little notch in the barrel just in front of the lock ring. There is a small lug on the split ring that fits in that notch. Mine was very tight, and although I knew better I finally just grabbed hold and pulled hard. It gave way and surprised me and the lock ring and the split ring and the teeny tiny little pin flew out onto the floor. I got incredibly lucky and found them all, especially the little pin (at least I hope there wasn't something else in there...). I would recommend putting the whole thing in a big clear ziplock bag or something if you do this, or so something to catch the parts in case it flies apart like that.

At 4:30 in the first photo of the split ring is the lug that goes into the barrel notch. The split in the ring opposite to that is what causes the tightness issue apparently. I think if the lock nut is rotated when the spindle is out, the lock ring closes too much and won't spring back. I used an xacto knife to wedge the split back open. I put the split ring into the lock nut to test it and the spindle slid easily through it.

It took me a while to figure out the pin goes into the wedge-shaped cutout in the split ring (has anyone been able to download the software from Starrett to view their exploded views? That would've really helped). Before I put it all together, I cleaned up some burrs on the split ring with a fine diamond hone. It was still really tight going back into the barrel, and a small bit of filing on some shiny spots on the split ring lug made it easier.

Getting it back together was very fiddly. I ended up doing it a half dozen times before getting it lined up so the spindle would go through. After a bunch of tries, I reversed the lock ring on the split ring and it finally went together and now it works as it's supposed to, and I can use the ratchet.

Now if I can just get it zeroed. It's off a half thousandth, and I cannot get it to move with the wrench. The wrench pin pulled out last time and boogered up the wrench hole, grrrrrr.... I have it soaking in Kroil now in case that may help.

Anyway, I hope this helps someone!





IMG_1629.JPG IMG_1630.JPG
 

Tony Wells

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#9
Yep, that's the way I remember it. I haven't had time to break one of mine down, so it looks like I don't need to now.

The barrel is a friction fit, so soaking should help that. It isn't supposed to be that hard to turn. A little warmth like just sitting under a lamp may help. No torch or anything.:)
 

royesses

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#10
Those photo's make what you were describing very clear now. It is a one roller sprag clutch. Very ingenious design. Thanks for sharing with us.
 

22405

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#11
Found this thread searching for pictures of the "Lock Ring" assembly for a Vintage Starrett No. 230 that I recently purchased on eBay. Upon receipt of the micrometer, the spindle was a little tight to turn and the lock ring was frozen in place. I put a little oil on the lock ring and it freed up and began to work. Time to give it a good cleaning and some oil. Without knowing better, I moved the lock on and off while I had the spindle out and the locking mechanism closed down tight and the spindle barely moved without considerable effort. After seeing the pictures of the parts that are in the lock ring assembly it was time to disassemble it and remedy the problem.

I suspect that what I found is the same for most vintage micrometers, years of old dried oil that looked like varnish, with plenty of dirt and grit...no wonder the lock ring assembly was frozen. What you don't see in the picture is the inner split ring, it has a slit in the sidewall making it very weak. When you apply the lock without the spindle it will collapse and it did. I used an exacto to open the gap, then verified that the spindle would fit without drag and the inner locking mechanism would still fit the outer ring. Cleaned, polished and oiled everything... it works like new.

Thanks for posting the pictures and the details, made this an easy fix.

Robert
 

EmilioG

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#12
There is a barrel spring for this mic. Was it present when you disassembled? You can order parts from Starrett if anything is worn.
 

22405

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#13
The parts I found inside were the same as pictured above. What does the barrel spring look like? What does the spring do?

Thanks
 

EmilioG

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#14
The parts I found inside were the same as pictured above. What does the barrel spring look like? What does the spring do?

Thanks
According to the Starrett 3d parts viewer, there is a spring. SPRING, BARREL10058-01
You can call or email Starrett and they will provide parts, .pdf parts drawings and info.
The Starrett 3d viewer can be downloaded, installed and seems to work on MS Internet Explorer only. (doesn't work in Chrome).
This model has been updated and is n ow the T230XRL., using 19 parts instead of 20.

I don't know what the spring does. I don't own any Starrett micrometers. I only see it in the 3d parts viewer.
T230RL Parts:
Illustrated Parts Catalog

Published Date: 2015-02-03

ITEM DESCRIPTION PART NO. QTY INFO

Illustrated Parts Catalog

Published Date: 2015-02-03

ITEM DESCRIPTION PART NO. QTY INFO
Printed: 2017-12-28
boxnone.gif 0OUTSIDE MICROMETER CALIPERT230RL boxshow.gif 1FRAME SUB ASSEMBLYNOT AVAILABLE1 boxshow.gif 2SHELL, OUTSIDE09990-01 boxshow.gif 3NUT, .375-5216414-01 boxshow.gif 4SPRING, BARREL10058-01 boxshow.gif 5LOCK NUT , #230 ASSEMBLYPT990601 boxshow.gif 6•RING, BINDER09209-01 boxshow.gif 7•RING, FRICTION05324-01 boxshow.gif 8•ROLL, BINDER05325-01 boxshow.gif 9RATCHET ASSEMBLYPT198321 10•CAP ASSEMBLYPT994451 11••RATCHET13196-01 12••CAP, RATCHET07671-B1 13•BODY, RATCHET #23019773-01 14•PIN, RATCHET .066D X .156LPT189761 15•SPRING, .041X.061X.188X.010X6PT076731 16•SCREW, #2-64 SLOT X .204 LONGPT197721 boxshow.gif 17WRENCH #3PT015261 boxshow.gif 18SHELL, ADJUSTING08752-01 boxshow.gif 19ANVIL07969-01 boxshow.gif 20SPINDLE07585-0
 
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Silverbullet

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#15
Thanks I have one to that's not right. I also own several Lufkin mics they have a very unique take up on the barrel threads it's like a back lash adjusters . If you take the barrel out past it don't just start tightening it back it'll jam up , you have to load the spring has you thread the barrel back in. Just trying to help not change or anything.
 

iainwhite

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#16
The parts I found inside were the same as pictured above. What does the barrel spring look like? What does the spring do?

Thanks
The spring is a slightly curved but flattish leaf spring that tensions the sleeve with the graduation scale against the micrometer frame.
It holds the sleeve in place but allows it be adjusted with the small wrench.

I did a picture with some screenshots from the parts viewer to try and make it clearer
 

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