Zeiss achroplan stuck

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imkap
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Zeiss achroplan stuck

#1 Post by imkap » Wed Jul 13, 2022 8:56 pm

Hi. anyone had success disassembling this one? I unstuck it but should clean it as there is a lot of gunk inside, so it sticks again after a few days. Stuck, stick I don't know how to use these words... You know what I mean.
I'm thinking the white ring should be unscrewed somehow, but I didn't have much success, I don't want to push too hard, as maybe it is not screwed in after all...

Thanks

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Adam Long
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Re: Zeiss achroplan stuck

#2 Post by Adam Long » Thu Jul 14, 2022 9:55 am

The only good resource I've found is here:

https://www-funsci-it.translate.goog/sc ... r_pto=wapp

I can't see any Zeiss infinity optics unfortunately. There was also this recent thread:

viewtopic.php?f=5&t=15363&p=121199&hilit=repair#p121199

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imkap
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Re: Zeiss achroplan stuck

#3 Post by imkap » Thu Jul 14, 2022 10:45 am

Adam Long wrote:
Thu Jul 14, 2022 9:55 am
The only good resource I've found is here:

https://www-funsci-it.translate.goog/sc ... r_pto=wapp

I can't see any Zeiss infinity optics unfortunately. There was also this recent thread:

viewtopic.php?f=5&t=15363&p=121199&hilit=repair#p121199
Thanks for the response
That's a great resource, but I've searched it already...

In the recent thread you linked they disassembled the internals and the blue ring with rubber is still on (white on my objective). So maybe it isn't unscrewable after all.

Usually internal barrel comes out the top of the objective but here I can't push it out, so the only solution I thought of was that this ring should be unscrewable, so it can come out on the other side.

The spring is located on the bottom of the objective.
When I unscrewed the ring that keeps the top most lens in place it cannot go out as it is attached to the spring somehow.
I'm not sure I would want to disassemble the internals as the optics are clean and all good...

The only other solution I thought of is that on the top of the objective the ring that keeps the objective from coming out, might not be a full ring, but just a peg keeping it in, so I could align the rail that the screw goes in and then push it out. But had no success in this... Maybe it is very dirty I'll try this again.
There must be a way for putting it out without disassembling all of the optics.

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Re: Zeiss achroplan stuck

#4 Post by imkap » Thu Jul 14, 2022 11:26 am

Forgot to mention, when turning the inner barrel and looking through the screw hole, I can see some holes there, not sure what these are for. I think there are 4

apochronaut
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Re: Zeiss achroplan stuck

#5 Post by apochronaut » Thu Jul 14, 2022 12:32 pm

You should never have to dig very deep into an objective to free the spring recoil. No access to lenses required.
With oil immersion objectives it is usually either 1 or 2 or all of :
1) oil having crept up between the inner and outer barrels and hardened causing friction. Resting oil objectives that have been penetrated by oil upside down allows oil to drift further up in the barrel.
2) a small amount of mechanical wear causing binding.
3) the spring having twisted and is exerting it's force a little diagonally causing the inner barrel to cock a bit sideways in it's bore. Turning the inner barrel against it's sleeve can cause that problem if one end of the spring is static and the other moves a bit. Some springs are quite delicate.

Post some pictures of the partially disassembled objective.

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Re: Zeiss achroplan stuck

#6 Post by imkap » Thu Jul 14, 2022 7:12 pm

apochronaut wrote:
Thu Jul 14, 2022 12:32 pm
You should never have to dig very deep into an objective to free the spring recoil. No access to lenses required.
With oil immersion objectives it is usually either 1 or 2 or all of :
1) oil having crept up between the inner and outer barrels and hardened causing friction. Resting oil objectives that have been penetrated by oil upside down allows oil to drift further up in the barrel.
2) a small amount of mechanical wear causing binding.
3) the spring having twisted and is exerting it's force a little diagonally causing the inner barrel to cock a bit sideways in it's bore. Turning the inner barrel against it's sleeve can cause that problem if one end of the spring is static and the other moves a bit. Some springs are quite delicate.

Post some pictures of the partially disassembled objective.
Thanks for your response, I think this objective has some sticky gunk inside, probably immersion oil, dirt and grease mix. Isopropyl seems most successful in dissolving the particular blend.

I have tried again this afternoon to pull or push it out and it just can't pass through. I won't be home for a week or so, I'll try again when I get back and post the pictures.

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Re: Zeiss achroplan stuck

#7 Post by imkap » Sun Jul 24, 2022 8:52 pm

apochronaut wrote:
Thu Jul 14, 2022 12:32 pm
Post some pictures of the partially disassembled objective.
This is as far as I went, not much of a disassembly, just removed the screw and the 'lid'...

On photo 1 through the screw hole you can see the groove in which the screw goes.
On photo 2 you can see the 'hole' which is there for some reason, not sure if they are of relevance.

Other 2 show the objective from the upper side...

Actually now it is a lot better than it was, it will get stuck again, but not as hard as it was.
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Re: Zeiss achroplan stuck

#8 Post by apochronaut » Sun Jul 24, 2022 11:54 pm

Sometimes the thread for the diaphragm forms a lip that stops the objective barrel from coming out the back. Is that the case with this?

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Re: Zeiss achroplan stuck

#9 Post by woyjwjl » Mon Jul 25, 2022 3:08 am

imkap wrote:
Wed Jul 13, 2022 8:56 pm
Hi. anyone had success disassembling this one? I unstuck it but should clean it as there is a lot of gunk inside, so it sticks again after a few days. Stuck, stick I don't know how to use these words... You know what I mean.
I'm thinking the white ring should be unscrewed somehow, but I didn't have much success, I don't want to push too hard, as maybe it is not screwed in after all...

Thanks

Image
You haven't used this, have you?
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Re: Zeiss achroplan stuck

#10 Post by imkap » Mon Jul 25, 2022 7:50 am

woyjwjl wrote:
Mon Jul 25, 2022 3:08 am
imkap wrote:
Wed Jul 13, 2022 8:56 pm
Hi. anyone had success disassembling this one? I unstuck it but should clean it as there is a lot of gunk inside, so it sticks again after a few days. Stuck, stick I don't know how to use these words... You know what I mean.
I'm thinking the white ring should be unscrewed somehow, but I didn't have much success, I don't want to push too hard, as maybe it is not screwed in after all...

Thanks

Image
You haven't used this, have you?
I have but it still slipped a few times :D

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imkap
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Re: Zeiss achroplan stuck

#11 Post by imkap » Mon Jul 25, 2022 7:50 am

apochronaut wrote:
Sun Jul 24, 2022 11:54 pm
Sometimes the thread for the diaphragm forms a lip that stops the objective barrel from coming out the back. Is that the case with this?
I think yes

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Re: Zeiss achroplan stuck

#12 Post by apochronaut » Mon Jul 25, 2022 9:21 am

Take the image of that lens spanner right out of your mind. You have a faulty spring mechanism externsl to the lens pack. You need not think of disassembling the lens pack.


So if the lens barrel will not come out the back( I presumed so because the rear diaphragm would otherwise serve double duty as the upper spring seat), then the ring with the white colour code must thread off.
One question though. The nose of the lens is spring loaded, correct?

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Re: Zeiss achroplan stuck

#13 Post by imkap » Mon Jul 25, 2022 10:03 am

apochronaut wrote:
Mon Jul 25, 2022 9:21 am
So if the lens barrel will not come out the back( I presumed so because the rear diaphragm would otherwise serve double duty as the upper spring seat), then the ring with the white colour code must thread off.
One question though. The nose of the lens is spring loaded, correct?
The whole nose moves back and forth with a spring, if that is what you ask.
I have tried to unthread the white ring but with no success, even did some damage to it :( . I've seen somewhere one can make a hole in between 2 wood planks, squeeze the objective inside and try to unscrew with that. Maybe there is another solution for gripping the ring, if you have some please say...

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Re: Zeiss achroplan stuck

#14 Post by apochronaut » Mon Jul 25, 2022 10:51 am

I have never had one of those objectives in my hands, so in saying the white ring unthreads I am going by what I know from other similarly constructed objectives. There are many ways that objectives are put together but that one looks like a front disassembly type. First make sure that the ring is definitely a separate piece, from the main outer objective shroud.

Once you have satisfied yourself that it is and should thread off, you need to assemble some tools. For that type of disassembly you need contact friction to grip the parts, not jaws. You will need two pairs of curved jaw vice grips or similar locking pliers as long as they are close in quality to vice grips. Many copies aren't and lack the fineness of adjustment. I use both a 10" pair to hold the objective fast and a 5" or 7" pair to turn the ring.. You will then need two leather straps, long enough to wrap around the objective. 5 to 10mm in thickness will do and ahout 1cm. wide. Light duty straps are a bit risky, in case they are weak and shred. Thicker straps are good because they absorb more compression.
Wrap a strap around the large part of the barrel about mid-way and adjust the vice grips to lightly clamp the strap, so that the strap slips on the barrel. Then release the vice grips and lightly clamp them without locking them, while simultaneously adjusting the thumbscrew, so that they clamp firmly without excessive pressure. The strap should not slip on the barrel. Then set the vice grip on a cloth with the objective thread down.
You can then fasten the smaller set of vice grips onto a second strap that is wrapped around the removeable ring following the same adjust the tension up procedure. The second set should be about 90° offset ftom the first. It is distinctly possible with enough tension to deform the objective shroud. I have never done this but I can see it happening, so for that reason always adjust up ftom a slack point, in fine increments just until you have enough friction.
Then rotate the smaller vice grip counter clockwise against the larger fixed part of the barrel. It should easily loosen but sometimes one of the vice grips needs slightly more tension. I have only ever encountered 1 instance where a left hand thread was used. If the ring doesn't loosen easily, then briefly try going the other way. Such a ring should not be that tight, so if it doesn't loosen, don't force it.You could then try introducing some penetrating oil or other anti seize fluid into the thread area.

Rubber can be used instead of leather ; something along the lines of a flat bungee strap but rubber compresses more and gripping that thin ring without the rubber squishing too much might be a little tricky.

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Re: Zeiss achroplan stuck

#15 Post by imkap » Mon Jul 25, 2022 11:31 am

apochronaut wrote:
Mon Jul 25, 2022 10:51 am
I have never had one of those objectives in my hands, so in saying the white ring unthreads I am going by what I know from other similarly constructed objectives. There are many ways that objectives are put together but that one looks like a front disassembly type. First make sure that the ring is definitely a separate piece, from the main outer objective shroud.

Once you have satisfied yourself that it is and should thread off, you need to assemble some tools. For that type of disassembly you need contact friction to grip the parts, not jaws. You will need two pairs of curved jaw vice grips or similar locking pliers as long as they are close in quality to vice grips. Many copies aren't and lack the fineness of adjustment. I use both a 10" pair to hold the objective fast and a 5" or 7" pair to turn the ring.. You will then need two leather straps, long enough to wrap around the objective. 5 to 10mm in thickness will do and ahout 1cm. wide. Light duty straps are a bit risky, in case they are weak and shred. Thicker straps are good because they absorb more compression.
Wrap a strap around the large part of the barrel about mid-way and adjust the vice grips to lightly clamp the strap, so that the strap slips on the barrel. Then release the vice grips and lightly clamp them without locking them, while simultaneously adjusting the thumbscrew, so that they clamp firmly without excessive pressure. The strap should not slip on the barrel. Then set the vice grip on a cloth with the objective thread down.
You can then fasten the smaller set of vice grips onto a second strap that is wrapped around the removeable ring following the same adjust the tension up procedure. The second set should be about 90° offset ftom the first. It is distinctly possible with enough tension to deform the objective shroud. I have never done this but I can see it happening, so for that reason always adjust up ftom a slack point, in fine increments just until you have enough friction.
Then rotate the smaller vice grip counter clockwise against the larger fixed part of the barrel. It should easily loosen but sometimes one of the vice grips needs slightly more tension. I have only ever encountered 1 instance where a left hand thread was used. If the ring doesn't loosen easily, then briefly try going the other way. Such a ring should not be that tight, so if it doesn't loosen, don't force it.You could then try introducing some penetrating oil or other anti seize fluid into the thread area.

Rubber can be used instead of leather ; something along the lines of a flat bungee strap but rubber compresses more and gripping that thin ring without the rubber squishing too much might be a little tricky.
Thanks, I'll try to soak the thread with isopropyl as it was successful in diluting the gunk inside. I'll find some leather and try this out... The ring looks pretty thin, so I suppose if it won't go, better not force and leave it as is

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Re: Zeiss achroplan stuck

#16 Post by Chas » Mon Jul 25, 2022 8:02 pm

I'll try to soak the thread with isopropyl
It can be very hard to get a volatile solvent into 'end to end' threaded parts, before the solvent evaporates from the outside. So a couple of suggestions;
A short piece of pipe maybe 1 or 2mm wider than the objective placed around the objective can trap the vapour next to the joint. e.g. Copper water pipe /a shotgun cartridge.
This might be just voodoo ; but I try to scratch into the junction between the two parts with a sewing needle ( biological 'mounted needles' seem too blunt). best done under a stereo microscope?
It never seems to take less than 25 minutes to free a seized thread with solvent (I use cigarette lighter fluid) and I have had the odd objective that has taken a full day&night too free up.

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Re: Zeiss achroplan stuck

#17 Post by imkap » Mon Jul 25, 2022 8:41 pm

I tried again unsuccessfully :oops:

One part of me wants to repair it, but another part (rational) wants to list it on ebay for parts...

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Re: Zeiss achroplan stuck

#18 Post by woyjwjl » Tue Jul 26, 2022 1:26 am

imkap wrote:
Mon Jul 25, 2022 10:03 am
apochronaut wrote:
Mon Jul 25, 2022 9:21 am
So if the lens barrel will not come out the back( I presumed so because the rear diaphragm would otherwise serve double duty as the upper spring seat), then the ring with the white colour code must thread off.
One question though. The nose of the lens is spring loaded, correct?
The whole nose moves back and forth with a spring, if that is what you ask.
I have tried to unthread the white ring but with no success, even did some damage to it :( . I've seen somewhere one can make a hole in between 2 wood planks, squeeze the objective inside and try to unscrew with that. Maybe there is another solution for gripping the ring, if you have some please say...
You don't use such tools, do you?
1.jpg
1.jpg (66.52 KiB) Viewed 2603 times
viewtopic.php?f=25&t=14788
No objective has ever stopped me from taking it apart, if I'm not being modest. :mrgreen:
Micrographers from China, thanks to the forum for providing a platform for exchange

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Re: Zeiss achroplan stuck

#19 Post by imkap » Tue Jul 26, 2022 5:11 am

woyjwjl wrote:
Tue Jul 26, 2022 1:26 am
imkap wrote:
Mon Jul 25, 2022 10:03 am
apochronaut wrote:
Mon Jul 25, 2022 9:21 am
So if the lens barrel will not come out the back( I presumed so because the rear diaphragm would otherwise serve double duty as the upper spring seat), then the ring with the white colour code must thread off.
One question though. The nose of the lens is spring loaded, correct?
The whole nose moves back and forth with a spring, if that is what you ask.
I have tried to unthread the white ring but with no success, even did some damage to it :( . I've seen somewhere one can make a hole in between 2 wood planks, squeeze the objective inside and try to unscrew with that. Maybe there is another solution for gripping the ring, if you have some please say...
You don't use such tools, do you?
1.jpg
viewtopic.php?f=25&t=14788
No objective has ever stopped me from taking it apart, if I'm not being modest. :mrgreen:
:mrgreen:

How do you call this yellow tool?

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Re: Zeiss achroplan stuck

#20 Post by woyjwjl » Tue Jul 26, 2022 6:01 am

Belt filter wrench mobile phone oil box wrench change oil wrench ball head filter filter mobile phone oil filter element disassembly tool
1.png
1.png (267.69 KiB) Viewed 2574 times

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Re: Zeiss achroplan stuck

#21 Post by apochronaut » Tue Jul 26, 2022 6:39 am

It is unlikely to be the tool that is the issue, since the method described has been used for dozens of objectives. Isopropyl isn't that great a solvent for grease or oil . I would be using a small amount of some form of penetrating oil there, since it is well exterior to the optics. You just need a drop or two.

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Re: Zeiss achroplan stuck

#22 Post by imkap » Tue Jul 26, 2022 1:21 pm

apochronaut wrote:
Tue Jul 26, 2022 6:39 am
It is unlikely to be the tool that is the issue, since the method described has been used for dozens of objectives. Isopropyl isn't that great a solvent for grease or oil . I would be using a small amount of some form of penetrating oil there, since it is well exterior to the optics. You just need a drop or two.
I think so too, but I don't have all the tools you described anyway... I'm afraid if I put oil and fail to disassemble that I'll never get rid of it.

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