Help with cleaning / restoring second hand Olympus BX40

[Garz]

Hello fellow microbe hunters!

I see there are a lot of knowledgeable people here when it comes to microscopes.

I am a near complete novice.
But I have been experimenting with an old Watson Microsystems microscope that i rescued from a garage sale about a year or so ago, with some halfway reasonable results, but I soon realised the limitations of this old, knocked about scope, especially since the optics were scratched and there was even mould inside several of the objectives when I got it.

As a result, I’ve been looking for a better microscope for some time, this was just a long process because I am on a tight budget.

I recently purchased this Olympus BX40 scope.
As you will see, it has also had a bit of a hard life. The previous owner knew v little about it, other than it was stored in a garage (apparently wrapped in plastic) for the last several years.
It has also had a couple of knocks in transit.

That said the glass components of the optics look to be in reasonable condition and I am not too concerned with cosmetics. So, i am hoping it can be salvaged in terms of restoring optical function.

As far as I can see the scope is complete, there are 3 objectives, one being 100x oil, the lamp is present and works, the stage works smoothly enough in all directions. The slide holder had taken a knock in transit but I think it can be tweaked back into shape well enough to work.

I would be very grateful for any help you could give me in terms of how to go about cleaning and restoring the scope to optimal function - Or at least as close to that as is able to be achieved on a DIY basis.
the stage upper surface is pitted with corrosion - so i think i am going to have to repair that
the slide holder was bent in transit - but i should be able to carefully tweak it back into shape

The scope will be used mainly for viewing Giemsa-stained thin blood smears at 1000x Under oil, with an emphasis on studying intra erythrocytic organisms.

I hope to be able to photograph images of my findings in detail.
I made a mount for a smartphone with a 12MP camera for my previous Heath-Robinson rig i and captured halfway acceptable images that way – but there was some loss of detail at the fine scale in 1000x images – mainly due to some slight mismatch in the autofocus function vs the microscope focus, I think.
I have a small lathe so I am hoping I can mount a more suitable digital camera - to improve on that within my budget – but have not investigated this direction yet.

Questions
1, Is anything obvious missing that you can see

2, How should one go about cleaning what look to be undamaged but v greasy / dirty lenses – without damaging them further – see the eye pieces for instance

3, anything else you might suggest I do while the instrument is in pieces

Thank you all in advance for your knowledge and assistance

G

[PeteM]

A web search will find instructions on cleaning. The Zeiss "clean microscope" PDF is one example.

One durable approach to restoring your stage is to repaint the chipped parts, lightly sand smooth, clean thoroughly, and then get a thin adhesive sheet of Teflon (PTFE) and cover the entire working surface. Trim it after it's in place. Cover the x-y scales with precisely cut thin masking tape so the Teflon doesn't adhere there.

There are a couple of tricky parts. First, if the sheet is too thick, you won't be able to raise the condenser high enough to get Kohler illumination. Check your range first; something like 0.01" should be OK, and thicker is often possible.

Second, you only get one shot at applying this, so take your time.

Third, this stuff typically comes in black, white, and semi-transparent versions. Even if you get the bubbles out, the semi-transparent will only look as good as the painted stage under it, if that's a concern. Delrin (acetal) self-adhesive sheet is another option. Either will provide a durable, smooth, gliding surface that will clean up easily.

Your slide holder can be tweaked to lie flat. You may have to clean and lube the swing arm pivot.

[Garz]

A web search will find instructions on cleaning. The Zeiss "clean microscope" PDF is one example.

One durable approach to restoring your stage is to repaint the chipped parts, lightly sand smooth, clean thoroughly, and then get a thin adhesive sheet of Teflon (PTFE) and cover the entire working surface. Trim it after it's in place. Cover the x-y scales with precisely cut thin masking tape so the Teflon doesn't adhere there.

There are a couple of tricky parts. First, if the sheet is too thick, you won't be able to raise the condenser high enough to get Kohler illumination. Check your range first; something like 0.01" should be OK, and thicker is often possible.

Second, you only get one shot at applying this, so take your time.

Third, this stuff typically comes in black, white, and semi-transparent versions. Even if you get the bubbles out, the semi-transparent will only look as good as the painted stage under it, if that's a concern. Delrin (acetal) self-adhesive sheet is another option. Either will provide a durable, smooth, gliding surface that will clean up easily.

Your slide holder can be tweaked to lie flat. You may have to clean and lube the swing arm pivot.

thanks Pete

i have been considering sanding filling and spray painting the stage upper surface after carefully masking around the painted area ( which will be just the area that is curranty matt black) - eg condenser opening , scale indicators etc
this would get around the height issue - as the paint will be only around 0.003" ( approx 75microns)

i will still need to scrape out the aluminium corrosion products in the pits and fill and sand it (will need to do this if applying a film also ) - so i am wondering if it s better to disassemble the stage components so i can work on only the top surface without getting dust and grit in the slides - is this something relatively straightforward to take a part and re-assemble or am i better off just carefully masking the parts i wish to avoid debris getting in

i found this Zeiss clean microscope guide - https://zeiss-campus.magnet.fsu.edu/art ... /care.html so if suitable i will gather those materials before tackling the optical components

[PeteM]

I'd take off the stalk with the x-y knobs. It's just a couple screws for it and two more for the front-back rack. That way, the stage is easily handled and can lie flat for painting.

It is then probably easier to thoroughly mask off other parts than remove the bearings and guides; if they're working OK as is. Generally, only the top and sides of the stage are worn, so you can mask off areas that would get grit or overspray.

The only problem with spray paint, unless it's something like powder coated, is that it will quickly wear from contact with slides and the slide holder arm. Flat or satin black canned spray paints meant for auto trim or wheels will cure a bit harder in my experience. These days, the better microscopes will have something like a ceramic coating. Older scopes will sometimes be retrofitted with Teflon etc. tops as previously described.

[Scarodactyl]

https://www.microbehunter.com/microscop ... 30&p=76310
Rattlecan paintjobs can come out real nice with proper prep.

[imkap]

Here you can find some great info about the older models, I think it should be helpful.

https://www.alanwood.net/olympus/downlo ... #bh2videos

[Garz]

https://www.microbehunter.com/microscop ... 30&p=76310
Rattlecan paintjobs can come out real nice with proper prep.

Nice Job - the colour choice makes a nice change too!

[Garz]

Here you can find some great info about the older models, I think it should be helpful.

https://www.alanwood.net/olympus/downlo ... #bh2videos

thanks - the one i have is actually a bit newer - a BX series - just not very well looked after

[Garz]

The only problem with spray paint, unless it's something like powder coated, is that it will quickly wear from contact with slides and the slide holder arm. Flat or satin black canned spray paints meant for auto trim or wheels will cure a bit harder in my experience. These days, the better microscopes will have something like a ceramic coating. Older scopes will sometimes be retrofitted with Teflon etc. tops as previously described.

good point - ref wear - i hadn't been thinking v long term.

[Garz]

i found this thread very useful also when it comes to cleaning implements and solutions

https://www.microbehunter.com/microscop ... ng#p113772

[Garz]

So far it looks like the scope has potential

The resolution and even apparent size and detail of red blood cells under 400x magnification is around that of 1000x under oil of my old scope

to date I have
• Repaired, filled and painted the stage top surface
• Straightened and refitted the slide holder
• Fixed the broken off lever on the lamp control
• Fixed corrosion in the lamp contacts
• Cleaned sticky residues from the frame and controls
• Cleaned front lens surfaces of objective lenses
• Cleaned eyepiece uppermost lenses
• Cleaned the condenser lens and recentred the condenser
• Removed and cleaned the lens in the Kohler unit
• Replaced the rubber feet

However - there is considerable contamination with debris in the optical path – and there is some kind of sticky greasy residue on most of, if not all of, the optical components externally and internally – even after my initial efforts at cleaning

For example, to clean the eyepieces – I removed the top ring of the eyepiece to expose the full surface of the uppermost lens – and allow better access to clean it - then used around 20 Q-tips with 99.99 % isopropanol in a gentle spiral motion from centre outwards while rotating the cotton bud away from the surface

After doing this 20times I was able to remove the most obvious sticky oily deposits that had semi hardened onto the lens – but remains is a persistent greasy / waxy film that seems fully hardened - and is not coming away with further applications of isopropanol – I will try to photograph it

The good news is there seems to be few visible scratches or damage to the lenses – so in theory it could be recovered - but the bad news is the entire scope seems to have been exposed to some kind of greasy atmosphere over a long period of time (almost like it was stored in the back of a chip shop! ) - as I can see a slight clouding of the internal glass components and even the mirror in the base.

Two questions
1. What can I use to clean the waxy ( I assume them to be some kind of hardened oil deposits) that are not moving with isopropanol – without damaging the lens coatings

2. It looks like I need to clean everything in the optical path - from the objective lens through the head and internal lenses in the eyepiece ( I had hoped to avoid this for fear of making it worse than it is - but I think its likely to be necessary to get the optical performance back to a useable level ) Can anyone give guidance on how to do this - is it basically an extrapolation of the q-tip method but at a smaller scale ??

[PeteM]

I'd try something other than IPA (ROR, etc.) for removing oil from the eyepieces and do a single dry wipe with soft lens tissue after wetting. A lens cleaner with a bit of soap in it may better capture the oil for removal. It could also be you've just been dissolving the oil and moving it around with those 20 swab applications?

A centering telescope can help you find which lens surfaces really need cleaning, once you get all the external surfaces clean (field lens, condenser, slide, front lens of objectives, perhaps the guard lenses of the head). Use a loupe or an inverted eyepiece and bright light to examine the objectives. The higher power ones, in particular, may be contaminated with immersion oil.

Also, if a tiny bit of internal debris isn't near one of the focal planes, it may not be much of a problem.

[Garz]

I'd try something other than IPA (ROR, etc.) for removing oil from the eyepieces and do a single dry wipe with soft lens tissue after wetting. A lens cleaner with a bit of soap in it may better capture the oil for removal. It could also be you've just been dissolving the oil and moving it around with those 20 swab applications?

A centering telescope can help you find which lens surfaces really need cleaning, once you get all the external surfaces clean (field lens, condenser, slide, front lens of objectives, perhaps the guard lenses of the head). Use a loupe or an inverted eyepiece and bright light to examine the objectives. The higher power ones, in particular, may be contaminated with immersion oil.

Also, if a tiny bit of internal debris isn't near one of the focal planes, it may not be much of a problem.

thanks Pete - i wondered if i was just moving oil around - but i paid very careful attention after the first say 10 q-tips - which were needed to get off all the visibly built up deposits - now the lens looks fully flat - but just has these oily streaks on it - but they dont seem to change after each subsequent application - leading me to think that its something hardened on the surface

pardon my ignorance - what is ROR - some kind of ester ? acetone

cantering telescope...... -will do some reading ....

[PeteM]

"ROR" (aka Residual Oil Remover) is one of the commercially available lens cleaners. Tiny squeeze bottles of the stuff - very convenient and fairly effective at removing fingerprints and other light oil residues - are available at Amazon and elsewhere.

Dried immersion oil may need a stronger solvent.

[Phill Brown]

Good luck with your latest project.
The BX should give better results than the Watson when finished.
I'm very biased to Watson.
I have other more recent scopes also.
The Microsystem 70 is enough to hook anyone into the world of microscopy.
Microsystem 70 optics in fully restored condition are still stunning for the time they were made, built to last apart from the first surface mirror on the Kohler which it's possible to have replacements made.
I rescued the prototype Kohler base from the basement of a shop full of assorted varying quality old items.
Zeiss coated lens cleaner spray is well worth the money.
I've found it to be the most effective.
000 sable brush is great for picking off individual specs without damage.

[Garz]

Good luck with your latest project.
The BX should give better results than the Watson when finished.
I'm very biased to Watson.
I have other more recent scopes also.
The Microsystem 70 is enough to hook anyone into the world of microscopy.
Microsystem 70 optics in fully restored condition are still stunning for the time they were made, built to last apart from the first surface mirror on the Kohler which it's possible to have replacements made.
I rescued the prototype Kohler base from the basement of a shop full of assorted varying quality old items.
Zeiss coated lens cleaner spray is well worth the money.
I've found it to be the most effective.
000 sable brush is great for picking off individual specs without damage.

thanks Phill

this image was taken with the watson -


is this the product you had in mind https://www.ebay.co.uk/itm/334495941186 ... R56D0L_QYg

[Hobbyst46]

Some types of old oil or grease, that survive isopropanol, can be removed with heptane or octane (or a similar hydrocarbon from a Pharmacy).
Do not try acetone - it can damage optical cements.
Try to blow away all dust and solid particles especially from inside-tube surfaces.
One advantage of the BX40 is its wider field of view relative to much older microscopes (like mine for example, 18mm FOV...)

[Phill Brown]

https://www.ebay.co.uk/itm/3344959

Yes, I have the other suggested solvents also.
For removing fungus I have found the Ziess cleaner the most effective.
Not saying it's not good to use whatever works for whatever residue.
Internal fungus can come back if it's not neutralised.
Kill it all, it's better to be sure.

[Garz]

Some types of old oil or grease, that survive isopropanol, can be removed with heptane or octane (or a similar hydrocarbon from a Pharmacy).
Do not try acetone - it can damage optical cements.
Try to blow away all dust and solid particles especially from inside-tube surfaces.
One advantage of the BX40 is its wider field of view relative to much older microscopes (like mine for example, 18mm FOV...)

thanks Hobbyst - i will find and try something petroleum based / non-polar for the grease

[Garz]

https://www.ebay.co.uk/itm/3344959

Yes, I have the other suggested solvents also.
For removing fungus I have found the Ziess cleaner the most effective.
Not saying it's not good to use whatever works for whatever residue.
Internal fungus can come back if it's not neutralised.
Kill it all, it's better to be sure.

that links not working Phil - was it the same as the one i linked to - or something else ?

i have a couple of things on hand which might be worth a try

i have a similar spectacle cleaning spray to the Zeiss lens cleaner - called "clear look" made for Dolland and Aichison group - by Calotherm manufacturing - which is intended for cleaning coated lenses

and i think i have some Zeiss lens cleaning wipes which i think are likely to have the same liquid formula in them as the spray ?

[Phill Brown]

Sorry, I only copied the title.
It's what you linked to.
Works on thread fungus better than anything else I tried.
Now my first choice go to for coated.
Only tried on Nikon,Watson,Euromex,GTvision,
Canon, Panasonic and Pentax

[Garz]

Sorry, I only copied the title.
It's what you linked to.
Works on thread fungus better than anything else I tried.
Now my first choice go to for coated.
Only tried on Nikon,Watson,Euromex,GTvision,
Canon, Panasonic and Pentax

thanks for confirming Phil

i don't think i have fungus in this one - - i know what a pain that is as the watson had it in the objectives -fine yellow threadlike structures - i think i read the optics in the BX are treated with some anti-fungal coating - which was a surprise to me -

[Garz]

OK - update is i am slowly working my way through repairing this scope.

i will need to clean all the optical components

i have done the mirror kohler unit and condenser as they were the easy bits

the eyepieces have fungus on some internal lens surfaces and i have had to dismantle to clean them


the Zeiss lens cleaning fluid is about the best thing i have found and is working well - so thanks for the tip for that

getting the lenses fully clean and speck free is a lesson in patience

but what is really proving testing is getting the cleaned lens elements back into the eyepice tubes the right way up and installed level / seated properly

the two that are most troublesome are the bottom lens which is heavily convex but has to go in from the top - and wants to rotate itself on the way in to be upside down ( heaviest side down) - and one of the intermediate lenses that is similar

its like dropping buttered toast - always lands sticky side down!

is there a knack to this that i am missing???

have tried tweezers to try to lower teh lens in but its no better - will rotate in teh tweezers

cheers!

[Garz]

OK - i am hoping some more photos might help

these are the eyepiece tubes of the BX

this is the one i have not fully taken apart and you can see the difficult lens in question installed where it should be


it has to go in from the top of the tube - with the flat side of the lens down - and the convex side up - which is exactly what it will not do if you just kind of get it as close as you can and then try to drop it into place

the little plastic flats in the internal bore that ensure its centred seem to have something to do with it - in that if it goes in even 10 degrees off horizontal it gets wedged and you cannot simply force it the rest of the way (i chipped the edge of a lens trying that)


in this last one you can see that there is another step a few mm above the one this first lens seats on - and its likely this that is catching one edge of the lens as it drops in and causes it to tilt and wedge


so it needs to be somehow lowered in almost perfectly flat all the way down - of at least to the top of the annular step where it seats

there must be a knack or a tool that does this - as it very likely they are hand built at Olympus - but its evading me at the moment

i would be grateful if anyone has suggestions

[Hobbyst46]

Why not prepare or find a stiff cardboard pipe, that has a perfectly straight end, of a diameter just slightly less than that of the lens; pass the pipe through the lower part of the eyepiece;
support the lens on that end and slowly lower the pipe until the lens reaches its proper position.
To prevent sliding and moving of the lens on the pipe's end, attach them to each other with sugar syrupe or vaseline, which can later be cleaned with water or heptane.

Alternatively, if you find a small round vacuum-based rubber button (sorry, don't find the exact term for it) that you can attach to the top surface of the lens from above (wet the glass and button surfaces with a drop of water to create strong vacuum); you can then fully control the lowering of the lens until it touches its final position.

[Garz]

Why not prepare or find a stiff cardboard pipe, that has a perfectly straight end, of a diameter just slightly less than that of the lens; pass the pipe through the lower part of the eyepiece;
support the lens on that end and slowly lower the pipe until the lens reaches its proper position.
To prevent sliding and moving of the lens on the pipe's end, attach them to each other with sugar syrupe or vaseline, which can later be cleaned with water or heptane.

Alternatively, if you find a small round vacuum-based rubber button (sorry, don't find the exact term for it) that you can attach to the top surface of the lens from above (wet the glass and button surfaces with a drop of water to create strong vacuum); you can then fully control the lowering of the lens until it touches its final position.

some excellent suggestions there thank you
i think i had somehow fixed in my mind that i could not touch the lens surface with anything during the process - but as you suggest - the very edge is not used once installed so the tube idea may well work

the one thought i had was to make 3 thin plastic strips to fit into the open end of the tube - between the 3 locating tabs -to guide the lens down - stopping it from catching on the step - the 3 supports rather than 2 would stop the flipping over on the way - i think the 3 locating tabs in the tube are significant and suspect this or some variant of it s how olympus originally do it.

thanks again
will try these approaches and report back

[Garz]

OK a variant of the above worked for me with the very problematic first / bottom lens - thanks to Hobbyst46 for the ideas

in case it helps others working on the eyepieces for the BX series

i didn't fancy getting anything sticky on the lens to hold it in place - as i haven't been having great success cleaning such things off the lens properly once its installed in the tube

1. i used a sheet of overhead transparency film -( my reasoning was that it would be easier to clean - softer than glass and less likely to have particulates that might scratch the lens in it ) i rolled it up until it was just fractionally smaller than the OD of the first lens that needed to go in
2. taped it at the size using masking tape
3. cleaned the ends and OD of the film tube and the eyepiece tube with alcohol
4. stood the tube on the work surface
5. rested the lens on top - convex side down
6. carefully lowered the large end of the eyepiece outer tube down onto it until it was perfectly aligned and the gently pressed the lens home till it was fully seated on the internal lip (it’s a v light interference fit in the tube)
7. turned both the tube and eyepiece the other way up before removing the film tube

i was then able to reassemble the remaining lenses into the tube without undue difficulty

both eyepieces are now cleaned and reassembled - and functional - but it seemed impossible to do so without getting the odd minute spec of dust in there
this is frustrating - i am however comfortable the the scope will be functional

i need to do the head unit next

[Hobbyst46]

Bravo for the great job !