Broken Microscope

[sdk113]

Hey there guys! I was hoping someone might be able to help me out.

I own an American Optical Sixty Spencer microscope. Recently, when using it, it became "locked" in the most zoomed in position. The coarse focus knob will not move and can only be jiggled. When I took the bottom of it off to look inside, I see that a piece had popped loose. It doesn't appear broken or bent, but I'm unsure how to reattach the pieces to get it functioning again! I will add some photos/a video.

Thank you in advance!

https://youtu.be/qvf6vSYjvco

This is a link to the youtube video where I show the microscope getting stuck and the two pieces off the bottom.

[apochronaut]

I have not had one of those around for quite a few years but I have most of a parts manual in my possession. It looks like a simple fix, as long as you have all the pieces.

[sdk113]

I have not had one of those around for quite a few years but I have most of a parts manual in my possession. It looks like a simple fix, as long as you have all the pieces.

I do have all the parts. I couldn't find the manual online, I would be very thankful if you'd share the info in yours with me!

[apochronaut]

Haven't forgotten about you. Will dig it out in the next day and pass on the relevant pages. if I have them.

[apochronaut]

I have a schematic for the entire internal mechanism of your microscope. I will photograph it and post it a little later but I thought first, I would let you know that several of the parts that you show in your you tube video are not on it. It is likely that the mechanism was modified at some point. I don't know whether yours is the newer or older design. I'll just go over what you already know, just so we are on the same page.
Everything is based on that cam turning in order to move the lever assembly up or let it drop down. What is happening obviously, is that the cam is is bypassing a critical point in it's rotation, slipping over the lifter and locking against it. It is missing whatever mechanism exists to stop it's rotation.

In the schematic, the cam( part # 31, figure 5) has a pin( part 32, figure 5) screwed into it on the opposite side of it's narrowest point; that point is where the lifter settles into after the lifter falls off of the cam lobe.
This looks to be a stop pin. Is there a place for this pin on your cam? It will be located just above a screw(part 33, figure 5) that locks the cam to the fine focus nut.

In your video, there are two parts you hold that are not on the schematic. They are probably parts of a different stop system.
There is a claw and then what looks like a spring, attached to the inspection door . Are there two indents in the side of the cam, that the claw fits into? If so, the claw works to catch the cam at it's required stop and the spring holds the claw against the cam. It is possible that the spring has broken. I am guessing at the way the mechanism works but it seems likely.

Here is all the pages I have for your microscope of one similar. It's pages 21, 24,25,26,27,28 and 29 from some manual. Some of the user manuals had parts lists and exploded diagrams at the end.

[apochronaut]

Two more pages.

[thomas.schwarz]

Unreal that you had that doc. Where is the OP?

[sdk113]

I still have not managed to repair it, unfortunately. The manual provided shows parts that aren't there! ):

[apochronaut]

It is a case of the design having been changed. You are missing a part : a spring. The flat bar that fits into the bottom door or plate has two little dogs bent over at the top, which engage into the focusing cam on the side. It is most likely called a cam tensioner. Those dogs provide a focus stop as well. On the other side of the bottom plate or door, your video shows a little steel ring. That is the remains of a spring that is attached to the door and then into the two reliefs cut into the middle of the cam tensioner at the other end.
The spring keeps the tensioner in place .
I'm not sure what the spring looks like. It obviously has a large loop at one end and probably a similar one at the other end to attach to the tensioner. The length would be determined by the required tension .
Maybe someone out there has a 60 with a similar design focus system and could measure the spring? Possibly a 50 would be the same.

[Element 56]

If you're in the USA you're welcome to send it to me for repair. Unfortunately I don't have the correct spring on hand so I would have to make it or fit one that's close.

This is the correct parts diagram for your instrument. You will probably need item# 36 too which I do have.

Kirby

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pg-19.jpg (104.19 KiB) Viewed 7057 times

[apochronaut]

If you're in the USA you're welcome to send it to me for repair. Unfortunately I don't have the correct spring on hand so I would have to make it or fit one that's close.

This is the correct parts diagram for your instrument. You will probably need item# 36 too which I do have.

Kirby

pg-18.jpg
pg-19.jpg

It looks like a pretty hefty spring. The ring attached to the door in the video is one of the coils. It doesn't help too much either, that the drawing of the door and spring on the schematic is pictured sideways.

[Element 56]

[/quote]
It looks like a pretty hefty spring. The ring attached to the door in the video is one of the coils. It doesn't help too much either, that the drawing of the door and spring on the schematic is pictured sideways.
[/quote]

Some of this is slowly coming back to me. I think the spring was pretty stout and I also think I remember these are a little tricky to put back together. It no surprise AO got away from this design and went with the design you posted.

Same old story, the grease gets hard and too much stress is put on #36, the nylon "nut" as they call it. It strips or breaks and the the focus knob can now be turned past the point of no return which breaks the spring. That little scenario is going from my memory of the last one I fixed over two years ago but I think that's is what the problem was with these. I made a new "nut' out of brass to fix the one I worked on but I have since found the nylon replacements which I bought from Keck Science Center. They have no less then 50 of these older 60's in service.

The OP may want to try to contact them for a replacement spring. I think the name of the person I dealt with was Walter and he could tell you more about fixing AO model 60's than I ever could. Hopefully he's still there.

Keck Science Center
925 N. Mills Ave.
Claremont, CA 91786
https://www.kecksci.claremont.edu/

Kirby

[henryr]

It seems that an AO sixty I'm considering may have a similar problem so all the responses and diagrams with parts list make me think I can fix it. However this scope is a bit different from all the other series sixty I've seen. The head has a second vertical viewing tube, maybe for a camera, and it also has a horizontal gizmo sticking out from the head opposite the angled mono viewing tube. Searching the web for a manual, I found the one shown in the Broken Microscope posts but nothing with a head shown in the attached photo. What does it do and could it complicate the repair? Any help will be greatly appreciated.

Thanks.
henryr

[BramHuntingNematodes]

It is my feeling that this gizmo must twist, push or pull to switch viewing from the front tube to the vertical tube. I have seen other AO 60s with an auxiliary tube and they also had this part.

[henryr]

Thanks for the info. I'm looking for an inexpensive scope for my 10 yr old my grandson and wanted one that could work with a camera and have a moveable stage. Now I don't know the quality of older AO eyepieces and objectives so I thought replacing them, with excellent condition Leitz and Zeiss spares I have, would be an upgrade. Would there be an optical improvement and will they fit this AO scope? And finally, are there any significant downsides of a monocular vs binocular head?

Thanks,
henryr

[deBult]

Often younger children have problems matching left and right eyepiece view. So mono is OK.

[BramHuntingNematodes]

There are no bad AO lenses to my knowledge.

[hans]

...horizontal gizmo sticking out from the head opposite the angled mono viewing tube. Searching the web for a manual, I found the one shown in the Broken Microscope posts but nothing with a head shown in the attached photo. What does it do and could it complicate the repair?

Illuminated pointer for teaching. That dual viewing head ("body" in AO/Reichert terminology) is shown in the Reichert 160 catalog:
https://user.xmission.com/~psneeley/Per ... oscope.htm
https://user.xmission.com/~psneeley/Per ... 160cat.zip

[apochronaut]

Thanks for the info. I'm looking for an inexpensive scope for my 10 yr old my grandson and wanted one that could work with a camera and have a moveable stage. Now I don't know the quality of older AO eyepieces and objectives so I thought replacing them, with excellent condition Leitz and Zeiss spares I have, would be an upgrade. Would there be an optical improvement and will they fit this AO scope? And finally, are there any significant downsides of a monocular vs binocular head?

Thanks,
henryr

Optical systems ftom the era of your 60 are pretty carefully engineered in order to harmonize the objectives and eyepieces. The maximum quality of the image is dependent on using the right eyepiece. The only possible improvement another maker's eyepiece could make to the system would be to increase the f.o.v. since the 60 was a budget student microscope but the chances of another brand eyepiece being corrected properly for AO objectives is minimal at best . Those are AO 161 eyepieces? 145 OR 146 would improve the field a bit but that's about it. Probably not worth it.

[henryr]

Thanks Apochronaut for the info. So I'll keep the Leitz and Zeiss stuff with my Leitz SM-M and Dialux. Now that brings me to another question I've wondered about. I'm really a neophyte when it comes to microscopes, but in the late 60s I worked in a metrology lab at the leading jet engine maker and consensus was that German optics were the best. Are the leitz 170mm and 160mm eyepieces and objectives really superior to the AO optics?

Thanks,
henryr

[apochronaut]

Optics are designed to provide an image modulated by those optics in certain ways. Those optics have specifications to do the job. I don't think that there is any doubt that certain optical designers have a few tricks that they use in order to fabricate certain systems to do a job, that another designer might overlook or be restricted from using by economic concerns. Those " tricks" usually result in a difference in specifications though, so the two can't really be compared . When competing products are designed by different companies or designed in different countries to the same specifications, there is not too much to choose between them, usually. Sometimes due to a depressed economy, companies in one country can outcompete those in a more developed country, putting out something of equivalent specifications a lot cheaper. This was the case for a big part of the latter half of the twentieth century , when Japan, Germany and Austria: all countries that were capable of producing good optical products, had sufficiently depressed economies that they were able to undercut products from, France, England and the U.S. and when at an equivalent price point , provide superior quality. Olympus was very good at that, assisted by the corrupt Japanese government and various Olympus executives that were outright crooks, so much so, that even in Japan, they are in jail. More than anything else it becomes a case of which government is superior at protection. In the U.S. there should have been a higher duty on , especially Japanese products. The optical industries of the healthier economies suffered badly from inadequate protection but consumers got cheaper goods, which theoretically translates into votes. Around Rochester , the industry morphed and moved on from consumer optics to industrial and military optics, where cost isn't such a factor. Same in the U.K. It would be hard to argue that Navitar or Cooke , do not produce optical products of as good a spec. as anybody : they are expensive, though. The U2 Hycon spy camera used a Baker lens. I'm thinking it wasn't cheap. Cooke cine lenses are the envy of any cinematographer not using one . Some will use no other. There is something called the Cooke look.

Is a Zeiss or Leitz 40X .95 planapo microscope objective , a better objective than an AO or Cooke/Baker 40X .95 microscope objective? Probably not but one might prefer certain qualities in one or the other and if you buy into myths such as German or Japanese optical superiority, then there is this thing called the placebo effect.