Zeiss removable nosepiece cleaning and lubrication

[Hobbyst46]

The following is trivial for some of us, but for me it was the first successful attempt so I thought I would share it.

I bought the removable nosepiece, age 60-70 years (?) for my microscope more than a year ago; at first it was fairly smooth, then began to show signs of friction. I put a drop of machine oil on the outer ring and incubated at 60C for an hour; it revived the smooth rotation, until yesterday I felt that the smooth rotation has turned into frictionless free rotation; it would not click and stop when objectives arrive at their proper positions. And some wiggle along the rim appeared. As if separation of the top main part from the bottom main part was occurring.

So - complete overhaul. The photos follow most of the steps.

The unit was placed on top of a paper towel in a shallow plastic tray, to prevent tiny parts from jumping away.
Screw no 1 is "reverse" - rotate clockwise to unscrew. Elementary ( ). Screw no 2 was found to be covered with black dried grease.
The depression under screw 2 contained a toothed ring and balls. And dried black grease.
When the top main part was separated from the bottom main part, a much larger toothed ring was revealed, with plenty (60 I think) more small balls, of the same diameter as the first group of balls. And dried black grease. No wonder there was a problem ! (regretfully I missed taking a picture of that view...).
This nosepiece has no lens, in contrast to the nosepiece of the Zeiss Universal for example.

I gathered all balls in a vial, and added a few ml of petroleum ether. Shaken and stirred, poured out the dirty liquid, repeated the process with the same solvent, then repeated with acetone.
Cleaned all parts with Q-tips dipped in petroleum ether. Dried with paper wipes.

For lubrication, 0.5ml of white Lithium grease was sucked into a disposable 1ml syringe. A #23 hypodermic needle was then pushed on. The syringe is extremely convenient to place small amounts of grease into the depressions formed by the toothed rings. Balls were placed, one by one, using a simple flat (not smooth end) forceps, into the grease-filled depressions. The large ball bearing was assembled first. Screws no 2 and 1 were carefully placed while centering against the top main part, and gently rotated without applying any force. The tightness of screw no 2 was adjusted for smooth rotation of the turret. Finally, screw no 1 was fully tightened.

[Hobbyst46]

(continued)

Incidentally, I am looking for a similar, additional nosepiece, as posted elsewhere.
P.S. in photo no 10, the large toothed ring is already inside its groove.

May I suggest for anyone in doubt that the overhaul of this nosepiece is less complicated than what may appeared.

[ImperatorRex]

Congratulations Hobbyst46.
Excellent documentation! I am sure it will help a lot of Zeiss Standard, Phomi, Universal and IM used microscope buyers and users. The principal to dismantle and relubricate is the same for all the old Zeis finite scopes.
As you have mentioned, the first screw has a reverse thread, so rotation is clock wise! Good to remember this.
Also I recomment to dismantle the nosepiece within a kind of tray, just in case some of the bearing balls get dropped, so they are collected and cannot drop on the table and the floor.
I enjoy putting back the small balls into the bearing .... like a puzzle. It is really relaxing, even better for a IM35 noisepiece ....much more of the small stell balls

[Hobbyst46]

I enjoy putting back the small balls into the bearing .... like a puzzle. It is really relaxing, even better for a IM35 noisepiece ....much more of the small stell balls

Thanks - and it is indeed fun !
[/quote]

[EYE C U]

WOW.. glad I never got mine apart, the bearings would have been a surprise..

[elvis_saya]

Thanks Hobbyst for this informative post! Coincidence that I just did the same for my 5 hole nosepiece earlier today and just saw this now - could've helped me even more.

I used denatured alcohol (I think its a combination of ethanol and methanol) to dissolve grease, and then a thicker #3 grease for the bearings, giving a 'tighter' feel.

[elvis_saya]

Noticed that in my nosepiece, the indexer has indents and the click-stop has an extra bearing. So 60+12+1 bearing balls. You need to put grease to hold this bearing in place during re-asssembly.





I have also cleaned an IM35 nosepiece - you can remove the telan lens, but it is not necessary. Also, there are 75 + 12 bearing balls.

[Hobbyst46]

Noticed that in my nosepiece, the indexer has indents and the click-stop has an extra bearing. So 60+12+1 bearing balls. You need to put grease to hold this bearing in place during re-asssembly.

I am not sure that the indexer, that small piece of metal shown on your second photo, is missing a ball in my nosepiece - although it indeed appears logical. There was no extra ball for the indexer. My nosepiece is just fine - smooth rotation and positive clicking into each of the five objective positions. Hopefully that ball on the indexer is not a must...
( complaint: why don't we, Zeiss microscope users, have maintenance manuals we deserve, especially against the complex engineering... )

[Charles]

Noticed that in my nosepiece, the indexer has indents and the click-stop has an extra bearing. So 60+12+1 bearing balls. You need to put grease to hold this bearing in place during re-asssembly.

I am not sure that the indexer, that small piece of metal shown on your second photo, is missing a ball in my nosepiece - although it indeed appears logical. There was no extra ball for the indexer. My nosepiece is just fine - smooth rotation and positive clicking into each of the five objective positions. Hopefully that ball on the indexer is not a must...
( complaint: why don't we, Zeiss microscope users, have maintenance manuals we deserve, especially against the complex engineering... )

Doron, I don't believe yours needs the index bearing since you have five bearings embedded in your turret which acts as the stop.

[Hobbyst46]

Noticed that in my nosepiece, the indexer has indents and the click-stop has an extra bearing. So 60+12+1 bearing balls. You need to put grease to hold this bearing in place during re-asssembly.

I am not sure that the indexer, that small piece of metal shown on your second photo, is missing a ball in my nosepiece - although it indeed appears logical. There was no extra ball for the indexer. My nosepiece is just fine - smooth rotation and positive clicking into each of the five objective positions. Hopefully that ball on the indexer is not a must...
( complaint: why don't we, Zeiss microscope users, have maintenance manuals we deserve, especially against the complex engineering... )

Doron, I don't believe yours needs the index bearing since you have five bearings embedded in your turret which acts as the stop.

Elementary, thanks, Charles ! now I grasp it !

[MicroBob]

Hi Doron,
nice documentation of the maintenance process!
For someone who doesn't like to make the effort to do this properly this can work quite well too: Problem is old hardened grease and dirt, especially in the outer ball race. This can be cleaned out quite okay by dunking it in lighter fluid for a while and moving it now and then until it moves lightly (but noisily because of the lack of lubricant). Then new grease can be applied either from the inside or from the outer slit. Then some oil to the bearing in the middle and it works fairly well again without even looking at the bearing balls. But of cause this doesn't always work well enough and it leaves some hardened grease and dirt inside, so it's a shortcut with drawbacks.

Bob

[elvis_saya]

( complaint: why don't we, Zeiss microscope users, have maintenance manuals we deserve, especially against the complex engineering... )

When you search for microscope service manuals:

Olympus - lots found, multiple websites hosting similar files
Nikon and AO - few found, good enough
Zeiss and Leitz - Download prohibited. Support is not desired. Removed from server

[viktor j nilsson]

( complaint: why don't we, Zeiss microscope users, have maintenance manuals we deserve, especially against the complex engineering... )

When you search for microscope service manuals:

Olympus - lots found, multiple websites hosting similar files
Nikon and AO - few found, good enough
Zeiss and Leitz - Download prohibited. Support is not desired. Removed from server

Very true! The good access to repair manuals was a major reason for picking up my Olympus Vanox AH. But luckily there are people on this forum with plenty of hands-on experience with Zeiss!

[EYE C U]

good stuff

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