Can an AO 100X oil objective be repaired?

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stjepo
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Can an AO 100X oil objective be repaired?

#1 Post by stjepo » Sat Jul 28, 2018 9:46 am

Taking into account my ignorance in AO microscopes I wonder if it is possible to repair this objective that only gives blurred images.

I don't see any visible damage into the lens. I don't know which is the problem.


Thank you for any help to allow me to jump my 'wall of stubbornness' in trying to repair this AO microscope.

Regards
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objeti01.jpg
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PATA-ARAÑA-100-AO-MICROSCOPE.jpg
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75RR
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Re: Can an AO 100X oil objective be repaired?

#2 Post by 75RR » Sat Jul 28, 2018 12:43 pm

I know (as you are a person that likes to fiddle about and fix things) that you are hoping that the answer is yes, but I can not see any sensible nor practical way to rescue that objective.
I suppose that in theory you could remove the affected lens from another objective (also effectively dead but due to other causes) and transplant it, but it is not worth the effort.
I recommend that you simply replace it with a more practical magnification say 20x or 60x.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
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Scarodactyl
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Re: Can an AO 100X oil objective be repaired?

#3 Post by Scarodactyl » Sat Jul 28, 2018 1:02 pm

Wow. Is that delamination or physical wear to the lens surface?

Hobbyst46
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Re: Can an AO 100X oil objective be repaired?

#4 Post by Hobbyst46 » Sat Jul 28, 2018 1:16 pm

75RR wrote: I recommend that you simply replace it with a more practical magnification say 20x or 60x.
Joining 75RR's reccomendation. This is the only sensible option.

IMO, and not specific to AO objectives: when the front pupil in the metal collar is so ruined and irregularly enlarged as in your photo, light passes through the rims of the lens, or might even bypass the front lens altogether and go directly into the next lenses inside. So the image will be deteriorated, irrespective of the integrity of the glass elements.
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MichaelG.
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Re: Can an AO 100X oil objective be repaired?

#5 Post by MichaelG. » Sat Jul 28, 2018 2:22 pm

I confess it took me a moment to realise what I was seeing, so I have rotated one image to make it more obvious:
IMG_2074.JPG
IMG_2074.JPG (70.28 KiB) Viewed 1471 times
IMG_2075.JPG
IMG_2075.JPG (37.13 KiB) Viewed 1471 times
This objective has obviously had a hard life, but I suspect that the damage to the aperture in the nose-cone might be due to someone 'cleaning' dried immersion oil off it ... with a pick.

The big question is: Is there still a window in that nose-cone ?
... The optical effect of 'oiling' just a jagged-edged hole would be "interesting". :o

MichaelG.
Too many 'projects'

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75RR
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Re: Can an AO 100X oil objective be repaired?

#6 Post by 75RR » Sat Jul 28, 2018 2:38 pm

... might be due to someone 'cleaning' dried immersion oil off it ... with a pick.
I suppose that is possible.
Acetone dissolves Canada Balsam - assuming that is what was used - nevertheless I do not think that the lens will be sufficiently salvageable.
If you wish to try ... nail varnish remover is usually acetone.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
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Hobbyst46
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Re: Can an AO 100X oil objective be repaired?

#7 Post by Hobbyst46 » Sat Jul 28, 2018 3:07 pm

It seems to me that the metal was (intentionally polished -?? unlikely) corroded, so the pupil in the metal collar is irregularly enlarged, rather than scratches on the glass.
On a 100X1.25NA Achro AO objective in decent condition, the ratio of the pupil diameter to the diameter of the flat surface on the front end should be 1:4.
On stjepo's 100X Planachro objective, the ratio is about 1:2.

EDIT:
I found the 1:4 diameter ratio from this AO objective:
https://www.ebay.ca/itm/AO-American-Opt ... SwoVNZ-0P1
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Objective front.jpg
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Last edited by Hobbyst46 on Sat Jul 28, 2018 4:26 pm, edited 1 time in total.
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MichaelG.
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Re: Can an AO 100X oil objective be repaired?

#8 Post by MichaelG. » Sat Jul 28, 2018 4:13 pm

Hobbyst46 wrote:... the pupil in the metal collar is irregularly enlarged, rather than scratches on the glass.
These are the scratches that made me think it had been attacked with a pick:
IMG_2074.JPG
IMG_2074.JPG (74.76 KiB) Viewed 1455 times
... and I was worried that the 'window' may no longer be present.

Hopefully, the hazy blue is that window, but I can't be sure.
The enlarged aperture, of irregular shape, is obviously a problem but could be re-built; but the absence of glass would be a disaster.

MichaelG.
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PeteM
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Re: Can an AO 100X oil objective be repaired?

#9 Post by PeteM » Sat Jul 28, 2018 6:31 pm

Have to say that's one of the worst-treated lenses I've seen. Beaten severely about the nose. And assaulted from the back. Plus a dent on the side where it may have been held in a vise. The front is so damaged it would be hard to clean off immersion oil in the future, even if the optics inside were somehow cleaned and properly aligned.

You could probably buy a good condition American Optical Series 10, with a complete set of plan lenses, for under $200. A replacement lens for maybe $50. As for the present lens -- I believe you have a lathe? What the present lens is good for is holding parfocal extenders and turning them down to the length needed.

stjepo
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Re: Can an AO 100X oil objective be repaired?

#10 Post by stjepo » Sat Jul 28, 2018 6:49 pm

75RR wrote:I know (as you are a person that likes to fiddle about and fix things) that you are hoping that the answer is yes, but I can not see any sensible nor practical way to rescue that objective.
I suppose that in theory you could remove the affected lens from another objective (also effectively dead but due to other causes) and transplant it, but it is not worth the effort.
I recommend that you simply replace it with a more practical magnification say 20x or 60x.
Good advice! I had to ask!

Regards

stjepo
Posts: 155
Joined: Wed May 23, 2018 10:25 am

Re: Can an AO 100X oil objective be repaired?

#11 Post by stjepo » Sat Jul 28, 2018 6:53 pm

MichaelG. wrote:I confess it took me a moment to realise what I was seeing, so I have rotated one image to make it more obvious:

IMG_2074.JPG

IMG_2075.JPG

This objective has obviously had a hard life, but I suspect that the damage to the aperture in the nose-cone might be due to someone 'cleaning' dried immersion oil off it ... with a pick.

The big question is: Is there still a window in that nose-cone ?
... The optical effect of 'oiling' just a jagged-edged hole would be "interesting". :o

MichaelG.
:lol: :lol: yes, looks like someone confused the cotton ear sticks with a drill...


Regards

stjepo
Posts: 155
Joined: Wed May 23, 2018 10:25 am

Re: Can an AO 100X oil objective be repaired?

#12 Post by stjepo » Sat Jul 28, 2018 7:00 pm

PeteM wrote:Have to say that's one of the worst-treated lenses I've seen. Beaten severely about the nose. And assaulted from the back. Plus a dent on the side where it may have been held in a vise. The front is so damaged it would be hard to clean off immersion oil in the future, even if the optics inside were somehow cleaned and properly aligned.
And you haven't seen the rest of the microscope that was sent to me!!!

Well It was a challenge for me... I enjoyed while I was repairing it!

Regards

stjepo
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Re: Can an AO 100X oil objective be repaired?

#13 Post by stjepo » Wed Aug 01, 2018 10:40 am

This is interesting:

https://user.xmission.com/~psneeley/Per ... ndends.htm

"I've never seen this before. See ebay# 7617439396. It is stated to be a Cat# 1024 AO Objective, made in Austria. It appears to be spring- loaded. I had the impression that the earliest spring-loaded objective that AO made was the 63x, and that -after- they had changed their name to AO-Reichert. Also, I thought they had before that time abandoned the Cat# 1024 in favour of higher Cat#s. The Austria comment is interesting -- did Reichert make objectives under the AO name? But here clearly is a 100x objective, marked simply AO, and with a spring-loaded tip??? Any info on this? Thanks, Steve<<"

That's It means that the tip of the Cat# 1024 should retract as it does my equivalent 100X (no offence) Correct objective? The one in my hands doesn't (maybe is glued)! Reason, maybe, I can not focus with it?

Reason I can not focus with it?

Any expert in AO can help?

Hobbyst46
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Re: Can an AO 100X oil objective be repaired?

#14 Post by Hobbyst46 » Wed Aug 01, 2018 11:36 am

stjepo wrote:...It means that the tip of the Cat# 1024 should retract as it does my equivalent 100X (no offence) Correct objective? The one in my hands doesn't (maybe is glued)! Reason, maybe, I can not focus with it? Reason I can not focus with it? Any expert in AO can help?
I am not an expert, but there is a clearly visible dent on the side of the objective, as shown by the lowest of the 4 photos at the beginning of this post. That dent, already mentioned by PeteM, means that the front part of the objective is no longer a perfect cylinder. In that case, regardless of any glue, its recession into the barrel is probably hindered. Combined with the other obvious mechanical flaws...
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apochronaut
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Re: Can an AO 100X oil objective be repaired?

#15 Post by apochronaut » Wed Aug 01, 2018 11:48 am

I will try one more time.
All American Optical, Cambridge Instruments, Reichert or Leica infinity corrected microscopes that were made in the Buffalo factory had retractable nosepieces, a design allowing the stage to remain stationary. Other microscope companies are now adopting it.
All objectives marked with an infinity symbol, made for the above brands of microscopes have fixed noses and do not retract.

The manufacture of microscope components is most practical when accomplished in batch runs and also most practical when costs are as low as possible. AO bought C.Reichert in 1962. Austria had a miserable economy then, having been drained by the Soviets since the second W.W. It therefore had very low production costs but a capable work force. Occasional batches of objectives, designed in Buffalo and usually made in Buffalo, were turned out in the Austrian plant. When Reichert, Austria began converting over from 160mm to infinity correctionin the 70's, some of their production models utilized the 34mm parfocal infinity corrected optical designs from AO. However, the Austrian models were engineered with conventional focusing of the stage, so those objective barrels incorporated spring loading and had a different shape to them. in at least two instances, AO had some objectives done in Austria, rather than Buffalo. It was probably about the time that their Buffalo production had turned to the second generation of planachros(1029, 1309 and 1311) in the early 80's and Austria was still making the older 1023 and 1024 , in the spring loaded format. To fill stock for parts and replacements, AO had a certain number of the Austrian spring loaded type barrels or completed objectives shipped over.
However, that entry on Neeley's site was based on looking at a picture of an objective, not having one in hand, so the assumption that it is spring loaded, although logical is incorrect. There were two such objective designs stocked in Buffalo, that came out of Austria : a 1023 and a 1024 and I have examined both types. Both , look like they are spring loaded but when they were made for the American instruments, the barrel was modified with a spacer, so as to render them as fixed nose objectives.

It would not matter anyway. Whether an objective is spring loaded or fixed, has no effect on focusing. Your objective is Euchred. Just buy another one but it would be best to get a 1029, 1129 or 1311. They are more recent designs and each has qualities that put it above the 1024. Better still, look for a 1014 with iris diaphragm. There is one selling out of Florida right now for not too much.

stjepo
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Re: Can an AO 100X oil objective be repaired?

#16 Post by stjepo » Wed Aug 01, 2018 3:54 pm

apochronaut wrote:I will try one more time.
All American Optical, Cambridge Instruments, Reichert or Leica infinity corrected microscopes that were made in the Buffalo factory had retractable nosepieces, a design allowing the stage to remain stationary. Other microscope companies are now adopting it.
All objectives marked with an infinity symbol, made for the above brands of microscopes have fixed noses and do not retract.

The manufacture of microscope components is most practical when accomplished in batch runs and also most practical when costs are as low as possible. AO bought C.Reichert in 1962. Austria had a miserable economy then, having been drained by the Soviets since the second W.W. It therefore had very low production costs but a capable work force. Occasional batches of objectives, designed in Buffalo and usually made in Buffalo, were turned out in the Austrian plant. When Reichert, Austria began converting over from 160mm to infinity correctionin the 70's, some of their production models utilized the 34mm parfocal infinity corrected optical designs from AO. However, the Austrian models were engineered with conventional focusing of the stage, so those objective barrels incorporated spring loading and had a different shape to them. in at least two instances, AO had some objectives done in Austria, rather than Buffalo. It was probably about the time that their Buffalo production had turned to the second generation of planachros(1029, 1309 and 1311) in the early 80's and Austria was still making the older 1023 and 1024 , in the spring loaded format. To fill stock for parts and replacements, AO had a certain number of the Austrian spring loaded type barrels or completed objectives shipped over.
However, that entry on Neeley's site was based on looking at a picture of an objective, not having one in hand, so the assumption that it is spring loaded, although logical is incorrect. There were two such objective designs stocked in Buffalo, that came out of Austria : a 1023 and a 1024 and I have examined both types. Both , look like they are spring loaded but when they were made for the American instruments, the barrel was modified with a spacer, so as to render them as fixed nose objectives.

It would not matter anyway. Whether an objective is spring loaded or fixed, has no effect on focusing. Your objective is Euchred. Just buy another one but it would be best to get a 1029, 1129 or 1311. They are more recent designs and each has qualities that put it above the 1024. Better still, look for a 1014 with iris diaphragm. There is one selling out of Florida right now for not too much.
Thank you very much to be back again.
As usual, very good advice... clear like a crystal (not as my 100X AO objective, though), the text mislead me. Good historical lesson.

Regards

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