I appreciate anyone that can help me with this. I just obtained an AO Spencer 4-1, I believe. I did not realize until after my wife had it home that it was missing the eyepieces. In cleaning it, I noticed there is a threaded place where something could be installed in the bottom of the head. I wonder if a lens is required at this point. There is a lens at the top of the arm. If I had eyepieces, I could probably figure out if it is usable but without the eyepieces I can't say.
In looking at the condenser, it appears there might be missing pieces but I am uncertain what.
I did not get a light source with this, and the first piece of glass the light would pass through appears to be frosted. Is this typical?
What I believe is the fine focus appears to be broken (the knobs directly on the arm with numbers). When turning that knob, the gears inside wiggle and hop about, but I do not observe any motion of the stage. How involved might it be to fix this? I am guessing the first step would be to find a small spanner wrench and remove the three screws from the arm?
Ultimately, the real question is if, having paid $40 for this, it is worth getting eyepieces for it and trying to fix the focus or if I should unload it to someone else for parts.
To sum up, I am hoping for help figuring out the following:
1. Is a lens in the head is necessary, desirable or helpful?
2. Are there parts needed for or below the condenser?
3. Should the first element between the light source and the condenser be curved, frosted glass?
4. Does anyone know if the parts of the fine focus are likely to be stripped or if they have more likely just come apart?
5. Is this worth getting eyepieces for or should I cut my losses?
Thank you for taking a moment to think through this with me.
Matthew
Missing parts for AO Spencer series 4
Missing parts for AO Spencer series 4
- Attachments
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- Arm.jpg (237.09 KiB) Viewed 1937 times
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- Head.jpg (321.3 KiB) Viewed 1937 times
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- Condenser.jpg (259.64 KiB) Viewed 1937 times
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- 20190822_064953.jpg (178.92 KiB) Viewed 1937 times
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apochronaut
- Posts: 6314
- Joined: Fri May 15, 2015 12:15 am
Re: Missing parts for AO Spencer series 4
The missing piece in the bottom of the head on the 4 is just an optical window, there to keep the head sealed and free of dust. You can get by without it, as long as it was not removed in order to replace or repair the deviating prism inside. Possibly , someone removed it in order to clean and never replaced it and as long as everything else in the head is ship shape, I wouldn't worry about it.
The eyepieces you require are AO # 146 10X W.F. Any eyepieces will work as long as they fit the tube but the sytem has built in corrections for tube length and field flattening and the 146 eyepieces seem to work best. Usually , a pair of # 146 can be bought fairly cheaply. They are a difficult eyepiece to clean, so buying an old set that might need work very cheap might be false economy.
Yes , there is a dispersion glass just inside the illuminator port.....normal.
The missing part where that small thread, pictured , is a lock screw for the condenser. It helps to have that because it keeps the condenser centered but any machine type screw of the correct thread will do. I will measure the exact thread size later and add the info.
I am unsure of what you are saying regarding the last point about the fine focus. How do you know the gears wiggle and hop about? Can you feel or hear something happening.? The motion of the stage in fine focus is very slight, so you have to look closely to see it moving.The actual mechanism is a fine lateral micrometer screw, acting on a pawl/cantilever that lifts the stage, so aside from the mechanism becoming stiff due to dried lubricant or the knob becoming loose as a result of the mechanism becoming too stiff, there is very little to go wrong with it.. The knobs themselves turn very freely but turning each counterclockwise against each other can easily loosen them enough that although the screws holding them on look snug, they have lost their clutch against the micrometer shaft. The knobs can be tightened by turning each clockwise against each other until snug.
It is also possible for the balls and or stage guide to become stiff over time and resist motion but that would cause the knobs to be stiff as well.
The eyepieces you require are AO # 146 10X W.F. Any eyepieces will work as long as they fit the tube but the sytem has built in corrections for tube length and field flattening and the 146 eyepieces seem to work best. Usually , a pair of # 146 can be bought fairly cheaply. They are a difficult eyepiece to clean, so buying an old set that might need work very cheap might be false economy.
Yes , there is a dispersion glass just inside the illuminator port.....normal.
The missing part where that small thread, pictured , is a lock screw for the condenser. It helps to have that because it keeps the condenser centered but any machine type screw of the correct thread will do. I will measure the exact thread size later and add the info.
I am unsure of what you are saying regarding the last point about the fine focus. How do you know the gears wiggle and hop about? Can you feel or hear something happening.? The motion of the stage in fine focus is very slight, so you have to look closely to see it moving.The actual mechanism is a fine lateral micrometer screw, acting on a pawl/cantilever that lifts the stage, so aside from the mechanism becoming stiff due to dried lubricant or the knob becoming loose as a result of the mechanism becoming too stiff, there is very little to go wrong with it.. The knobs themselves turn very freely but turning each counterclockwise against each other can easily loosen them enough that although the screws holding them on look snug, they have lost their clutch against the micrometer shaft. The knobs can be tightened by turning each clockwise against each other until snug.
It is also possible for the balls and or stage guide to become stiff over time and resist motion but that would cause the knobs to be stiff as well.
Last edited by apochronaut on Fri Aug 23, 2019 2:37 pm, edited 1 time in total.
Re: Missing parts for AO Spencer series 4
Thank you. That is very helpful and I am guessing that about $70 is reasonable for this setup so I'll go hunting those eyepieces.apochronaut wrote: I am unsure of what you are saying regarding the last point about the fine focus. How do you know the gears wiggle and hop about? Can you feel or hear something happening.? The motion of the stage in fine focus is very slight, so you have to look closely to see it moving.The actual mechanism is a fine lateral micrometer screw, acting on a paul/cantilever that lifts the stage, so aside from the mechanism becoming stff due to dried lubricant or the knob becoming loose as a result of the mechanism becoming too stiff, there is very little to go wrong with it.. The knobs themselves turn very freely but turning each counterclockwise against each other can easily loosen them enough that although the screws holding them on look snug, they have lost their clutch against the micrometer shaft. The knobs can be tightened by turning each clockwise agsinst each other until snug.
When operating the fine adjustment knobs, there is little or no movement of the stage, but there is noise inside the arm and the shaft between the two knobs bounces and wiggles without any consistency relative to turning motion--that is, it turns a bit without doing anything and then there are little clicks or pops and it wiggles. If you push or pull the fine adjustment knobs in toward or away from the arm while turning, sometimes the shaft between slips side-to-side and the stage wiggles but does not really move up or down.
I guess I will take it apart and see what I find. Hopefully a gear has come loose and can be re-positioned with a set screw or something. If I can't figure it out, I'll post again.
On the condenser, I can track down a screw. Is it typically a knurled one or would it make more sense to just use an easy-to-find phillips head or a set screw?
What I was actually wondering about is that the bottom of the condenser looks like it has a space for another piece with the two openings that look like something would go up into that space and turn to set. Was just wondering what would go there and whether it is necessary.
Does anyone have a spare illuminator or anything they are selling?
Thanks again!
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apochronaut
- Posts: 6314
- Joined: Fri May 15, 2015 12:15 am
Re: Missing parts for AO Spencer series 4
There are no gears in that mechanism. The mechanism is quite simple and can be accessed by first removing the 2 large hex allen screws from under the base that hold the arm to the base. Then remove the 3 pin bolts that fasten the stage section to the arm.
You will then see that the fine focusing system is in two sections. A drive system, which consists of the lateral micrometer screw and cantilever arm and the lift section, which consists of a block attached through the coarse focus block to the stage. The cantilever moves the stage relative to the arm up with pressure and allows it to fall down with gravity. There are 8 ball bearings that the focus block rides on. My guess is that the stage guide has hardened lubricant and might be stuck, failing to allow the stage to return by gravity. Hopefully, nothing in the cantilever or micrometer has been broken by force. The knobs are designed to spin on a slip clutch. You may have to disassemble the ball and track, you may not have to. The smoothness and precision of the system is in the micrometer screw, so if that works well, a simple relubing of the ball and track should suffice.
With regard to a lamp socket. They are hard to find and when you do find one, the centering screws are usually missing. Those are 4-40 thread and about an inch long, so a standard screw replacement is possible but likely only as a special order. Another option might be an led flashlight of the correct bore size or an illuminator from another scope. I think the right angled one from a Reichert Zetopan fits, probably others. You will need a transformer for any microscope illuminator.
The push and turn housing on the bottom of the condenser, I have not seen before. The series 2/4 had facility to accept a set of apochromat objectives. With the older stands that used the apochromats, there was an auxilliary lens that could be slid in under the condenser in order to use a low power scanning objective and have a fully illuminated field. It is possible that with the 2/4, they briefly had a push in and turn aux. lens. All that I have seen used the later swing in type, which became standard for 50 years. It isn't a feature that you need worry about.
The missing screw is a knurled one but it only becomes a factor , if you need to change condensers. If you are using only BF, then the condenser would only be removed for the occasional cleaning and any short screw would do. The tip of the screw is thin and rounded off, so it engages the dovetail over a minimum surface area. Your best bet as a non oem part would be an allen grub type screw with a tapered end or you could taper off the end of any screw or bolt that fits.
You will then see that the fine focusing system is in two sections. A drive system, which consists of the lateral micrometer screw and cantilever arm and the lift section, which consists of a block attached through the coarse focus block to the stage. The cantilever moves the stage relative to the arm up with pressure and allows it to fall down with gravity. There are 8 ball bearings that the focus block rides on. My guess is that the stage guide has hardened lubricant and might be stuck, failing to allow the stage to return by gravity. Hopefully, nothing in the cantilever or micrometer has been broken by force. The knobs are designed to spin on a slip clutch. You may have to disassemble the ball and track, you may not have to. The smoothness and precision of the system is in the micrometer screw, so if that works well, a simple relubing of the ball and track should suffice.
With regard to a lamp socket. They are hard to find and when you do find one, the centering screws are usually missing. Those are 4-40 thread and about an inch long, so a standard screw replacement is possible but likely only as a special order. Another option might be an led flashlight of the correct bore size or an illuminator from another scope. I think the right angled one from a Reichert Zetopan fits, probably others. You will need a transformer for any microscope illuminator.
The push and turn housing on the bottom of the condenser, I have not seen before. The series 2/4 had facility to accept a set of apochromat objectives. With the older stands that used the apochromats, there was an auxilliary lens that could be slid in under the condenser in order to use a low power scanning objective and have a fully illuminated field. It is possible that with the 2/4, they briefly had a push in and turn aux. lens. All that I have seen used the later swing in type, which became standard for 50 years. It isn't a feature that you need worry about.
The missing screw is a knurled one but it only becomes a factor , if you need to change condensers. If you are using only BF, then the condenser would only be removed for the occasional cleaning and any short screw would do. The tip of the screw is thin and rounded off, so it engages the dovetail over a minimum surface area. Your best bet as a non oem part would be an allen grub type screw with a tapered end or you could taper off the end of any screw or bolt that fits.
Re: Missing parts for AO Spencer series 4
It's good to start with realistic expectations. This condition is normal for a $40 microscope that is probably older than you are.
I think a good approach, when buying a microscopes of this age, to get two or more compatible microscopes and keep the best stuff from each. That's what I and others here have done with the 4-series and the 10-series and it works well. Your investment is not large--in fact, it has been ridiculously small. The next step if I were you would be to buy another 160mm AO microscope somewhere with complementary working stuff. Keep the best head, the best nose, the best condenser, the best body, the best objectives, etc. from the pair.
If it were me, I'd probably consider this microscope to be the source of spare parts for a different one I'd pick up on ebay or craigslist. Spend $100 or $150 bucks and get one with a working illuminator and focus mechanism.
Of course, it's also not crazy to eat your $40 investment and pick up a different model, such as a 10 series. They seem to be more common, as are their parts.
BTW are you within driving distance of DFW by any chance?
I think a good approach, when buying a microscopes of this age, to get two or more compatible microscopes and keep the best stuff from each. That's what I and others here have done with the 4-series and the 10-series and it works well. Your investment is not large--in fact, it has been ridiculously small. The next step if I were you would be to buy another 160mm AO microscope somewhere with complementary working stuff. Keep the best head, the best nose, the best condenser, the best body, the best objectives, etc. from the pair.
If it were me, I'd probably consider this microscope to be the source of spare parts for a different one I'd pick up on ebay or craigslist. Spend $100 or $150 bucks and get one with a working illuminator and focus mechanism.
Of course, it's also not crazy to eat your $40 investment and pick up a different model, such as a 10 series. They seem to be more common, as are their parts.
BTW are you within driving distance of DFW by any chance?