AO series 10 refurb.

[apochronaut]

I was asked to find a microscope for a friend's son, who is going into grade 9. Long gone are the days, when 12 year olds started out with a Tasco or Lumex, since used R.M.S. microscopes are so common and cheap. I had a derelict series 10 frame, which I collected somehow in a job lot, and was keeping it for parts. Very seldom do series 10 scopes ever need parts, unless they go missing. It had a seized coarse focus, the nosepiece could do the twist, someone had been into the focus mechanism from above, there was a screw missing, no head, no illuminator, and the left hand stage was loose and had backlash. The microscope had been used to death, poorly maintained and was filthy.
I had an illuminator with a detached mirror, and a head with a really good culture of fungus growing somewhere that affected the left side only, a pair of dirty eyeppieces and extra dirty AO infinity achromats. I also had an abbe 1.25 condenser, covered in a nice greasy coating of dirty immersion oil; right down to the dovetail. One of the cork feet was missing.
Picture 1 shows the general state of the frame but by the time I considered doing this thread, it had been scrubbed down with a toothbrush and detergent. Originally, it was noticeably grimey.
Picture 2 shows the focus worm from below.
3 the top cover missing a screw and the other 3 loose allen screws.
4 shows the relay mechanism in the arm and over to the yoke, after the cover is removed.
Picture 5, the loose nosepiece.

[PeteM]

Not sure you're going to be able to build up much suspense here, Phil. Pretty sure this story has a happy ending - what with the Series 10 being a great microscope and you the undisputed expert in all things A.O.

Would be interested to know how you chose to deal with the fungus.

[apochronaut]

This will be continued in 5 picture increments. There are 17 pictures in all covering the refurb., to completion.

The stage was an uncommon left hand version and needed a full refurb itself, so I pilfered a fairly good stage from another, much better instrument.
One of the defects that old 10's can suffer from, and I do not know how they get this way, is that the stage lock can be found to be out of position. It is impossible for the stage lock to get out of position by itself, so it can be assumed that at some point such a stage has been removed and then the lock has not been properly positioned upon assembly.
Picture 6, shows the stage lock in the incorrect down position.
Picture 7, shows it in the correct position( stage is upside down in the picture), above the focus knob. It locks by moving the lever, forward toward the stage. The position of the locking lever can be disturbed by allowing the tensioning screw on the obverse side to back off, which is shown in picture 8.
Picture 9 shows the actual locking mechanism with the tightening pawl, that works against the dovetail. The stage is easily adjustable on the dovetail for longer objectives, so infinity D.I.N. objectives can be retrofitted to the series 10, as long as you changed the head too.
Picture 10 shows the replacement right hand stage, selected for the microscope. You can see the locking lever in the correct position on the other side.

[apochronaut]

The seized focus was most probably thought to be a mechanical problem by a previous owner, or serviceman. Putting a fair amount of torque on the focus knob( with a heavy glove and a firm grip), showed a tiny bit of movement, so it was pretty clearly hardened grease. In picture 2, either end of the worm gear, enters a bearing in the column. An application of light machine oil, at each of those points, quickly allowed enough back and forth movement, to get the focus happening.
Picture 11 shows the tensioning side of the coarse focusing. Removal of the large nut tensioning the knob against the clutch, as well as the small allen locking screw in the knob itself, allows access to the exit side of the shaft bearing, as well as the tensioning clutch.A couple of drops of the same machine oil there, as well as at the same point inside the opposite knob on other side, freed up the focusing quickly. The clutch was cleaned of old grease, relubed with damping grease and all reassembled. Final adjustment of the coarse focus, is a matter of trial and error. Loosening or tightening the large nut holding the knob against the clutch, by relieving the allen locknut in the knob takes only a few minutes.
Picture 12 shows the possibility of adjusting the nosepiece for a conventional position. It is adjusted and centered by loosening the 3 allen screws in the nosepiece dovetail. I have never seen one of these with a conventionally aligned nosepiece but it is possible.
Picture 13 shows the nosepiece properly aligned and centered in the reverse position.
Picture 14 shows the older cat. # 1036-A tungsten illuminator for the 10. It takes an 18 watt tungsten push and turn bulb, driven by a remote 6 volt transformer. The 2 large Philips mounting screws are visible in picture 2.
Picture 15 shows the field diaphragm removed from the illuminator, by removing the two knurled adjustment screws. The adjustable first surface mirror was off in this illuminator, so I reglued it with epoxy. It is center cemented on the back of the mirror. Mirror adjustment is from below. Three spring loaded adjusting screws are available by removing the illuminator bottom plate.

[apochronaut]

Picture 16 is an old dirty binocular head. The binocular prism and first surface mirror section is removed from the housing by removing 4 slot machine screws that are installed upside down up into the diopter section. With them out and the one slot screw fastening the focus follower for the telon lens out, the entire set of optics can be lifted out, leaving only the deviating prism and telon lens in the bottom.
All of the optics can be accessed with bent shaft swabs, so cleaning all the surfaces can be done without any removal.

The problem with this head, turned out to be a surface fungus on the hardest to reach surface, on the deviated left surface of the deviating prism. Removing the three slot screws in the bottom allowed the entire deviating prism mount to come out and as before, carefully placed and conformed swabs allowed the complete removal of the surface fungus. The reassembled clean head works nicely.

Picture 17 shows the completed microscope, with a set of 4X .09, 10X .25 , 45X .66 and 100X 1.25 achromats, a 1.25 N.A. abbe condenser and cat.# 176 10X W.F. eyepieces installed. A med. blue clear filter above the field diaphragm window, completes the optics.

Microscope works great....nicer brighter background field than my phase version, so I guess I have a bit of work to do on my own head.

[rnabholz]

Nicely done Apo,

Your friend's son is a lucky fellow, a highly capable AO 10 stand that has been gone through by your extremely capable hand. Pretty hard to beat!

Rod

[apochronaut]

Thank you, Rod. Hard to remember exactly but most of those parts came in a couple of really cheap joblots, so I'm guessing that the total for the microscope would be in the 50.00 range. I don't use the achromats much but every time I have the opportunity to use them, I get surprised at how good they are for their time. Hard to believe those optics with that bright wide field were available in 1962! I have a series 10 catalogue without a date which has no zip codes after the AO regional office addresses and they all have alpha numeric telephone numbers, except Toronto.

[rnabholz]

Thank you, Rod. Hard to remember exactly but most of those parts came in a couple of really cheap joblots, so I'm guessing that the total for the microscope would be in the 50.00 range. I don't use the achromats much but every time I have the opportunity to use them, I get surprised at how good they are for their time. Hard to believe those optics with that bright wide field were available in 1962! I have a series 10 catalogue without a date which has no zip codes after the AO regional office addresses and they all have alpha numeric telephone numbers, except Toronto.

I am always surprised at the bargains I see on Ebay for AO 10's. Commonly available for under $100, with parts stands half of that.

I have bought a couple of them, a little lubrication, and some cleaning and they were ready to go. The paint on these holds up very well, they shine with a little elbow grease.

The objectives and eyepieces are cheap and readily available too.

I see darkfield condensers regularly for less than $30.

Moving back and forth between my 50's era AO4 and the 10, I am always reminded of the wide field difference. It must have been a welcome improvement for those using these scopes for hours each day.

Yes, I am a fan.... ;^)

[apochronaut]

Yes. the apochromats, as was the case with all apochromats of the era, require compensating oculars, which do have a restricted f.o.v.
The 4 did have W.F. eyepieces though, and when used in conjunction with the standard achromats, yield the same field as the 10, albeit with poorer edge correction.
Having used almost all of the Spencer or AO stands made after W.W.I and a few before, the series 4 stands out as a bit of an anomaly. Aside from the totally unique # 8, the 4 was the first general purpose stand that they produced that could be reversed but it heralded a new era for AO, with a focusing stage. They also toyed with the compensating telon lens, something later refined in the subsequent 2 generations of infinity corrected optics and later adopted by Reichert and Leica. Whatever their thoughts were with the series 4, which used the same conventional convergent optics as the previous scopes, they didn't stay there for long because it was the one and only focusing stage microscope they made, and they quickly diverged in their thinking to infinity correction with focusing objectives.

Having to use different sets of eyepieces with different types of objectives is obviously burdensome. AO obviously committed to a condition where ALL objectives would be engineered to require the same compensations as the apos. With the introduction of the infinity system, all objectives, achromats, planachromats, apochromats and planapochromats received further compensation in the telon lens, so the same W.F. eyepieces could be used with all of them, so W.F. performance came to the first generation of AO apos, made for the infinity scopes.

[MicroBob]

Hi Apochronaut,
it's nice to see that your friends son will now be able to start microscopy with such a well refubished quality microscope. May be an interest is founded and he will continue to use it a long time.
These American Optical microscopes are more or less non existent in Germany. They look really nice and have their design specialties. May be one day I get one into my hands. Right now I have already too many othe microscope projects on my "to do when there is time" list.

Bob

[apochronaut]

The Reichert Neovar 2 was quite similar in function to the AO series 120 but looks like a scaled down AO/Reichert Diastar. The Neovar 2 used AO infinity corrected 34mm parfocal optics; AO designs , made in Austria, except for the 63X, which was an Austrian design( I have the prototype that they sent to Buffalo for approval, to mfg. for the AO series 110/120). All the AO or Reichert 63X were subsequently made in Austria.
The Reichert Diavar 2 was more similar to the AO/Reichert Diastar but didn't have the reverse nosepiece and used some of the older Reichert physical designs, faithful to the Zetopan for instance. It was fitted with the D.I.N. 45mm parfocal infinity optics.

Either of those would have been sold in decent quantities in the 70's and 80's, on the continent, so you might be able to snag one of those, if you felt inclined.

[MicroBob]

Thank you for this comparison! Newer Reichert microscopes are quite scarce, compared to man other makers, but probably easier tot find than an American Optical microscope. I will install a permanent ebay search, and probably at some point of time soething will turn up.
This year I got a set of extremely scarce collets for my small series milling machine and a low production number circular saw this way, after waiting two years or so.

[apochronaut]

Beware of the Neovar and Diavar; they are both 160mm and use the same optics as the Zetopan.
Here is a German forum thread, discussing the Neovar 2 for a bit.
https://www.mikroskopie-forum.de/index.php?topic=1613.0

and here is a 1976 catalogue for the Diavar 2; http://www.science-info.net/docs/reiche ... avar_2.pdf