carl zeiss jena coarse focus mechanism?

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PeterArmitage
Posts: 36
Joined: Fri Oct 12, 2018 1:11 pm

carl zeiss jena coarse focus mechanism?

#1 Post by PeterArmitage » Fri Dec 28, 2018 10:42 am

Do any of you have experience dismantling, cleaning and greasing the coarse focus mechanism in a Carl Zeiss Jena Ergaval or Amplival microscope? I can't figure out how to completely dismantle the mechanism, and would appreciate advice re. how to proceed further than what you see in the appended photos. I took the base off and greased the gears as best I could, but I fear that I over greased them. As a result, I'm getting some slippage on the focus. I used a heavy grease for the lubrication, namely, Nyogel 795A. Thank you.
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MicroBob
Posts: 1625
Joined: Sun Dec 25, 2016 9:11 am

Re: carl zeiss jena coarse focus mechanism?

#2 Post by MicroBob » Fri Dec 28, 2018 2:19 pm

Hi Peter,
I can't help you here but with Zeiss Jena there is one general tip: They used grease that had an unusual tendency to harden. This can be a problem when dismantling because things just don't move when you loosen a screw. It helps a lot to soak the microscope micus optical components in warm temperature (60°C). This can be done with an IR lamp for example.

Bob

Hobbyst46
Posts: 2243
Joined: Mon Aug 21, 2017 9:02 pm

Re: carl zeiss jena coarse focus mechanism?

#3 Post by Hobbyst46 » Fri Dec 28, 2018 2:31 pm

Not a Zeiss Jena but on my Olympus VMZ rack the Nyogel 767A does a good job. In the Nye literature, the 767A, rather than tyhe 795A, is recommended for microscope focusing rails. I bought a 50g tube from Amazon.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

PeterArmitage
Posts: 36
Joined: Fri Oct 12, 2018 1:11 pm

Re: carl zeiss jena coarse focus mechanism?

#4 Post by PeterArmitage » Fri Dec 28, 2018 11:40 pm

Thanks MicroBob and Hobbyst46 for your replies. Yeh, I heard that the Zeiss Jena microscopes had "Russian tank grease" that hardened like glue. I have been using heat to help loosen up the badly stuck parts. The coarse focus is fairly well loosened up now, but not completely. But the new problem is probably that the replacement grease, Nyogel 795A, is too light. I'll try the heavier grease.... All the same, I need to get the focus mechanism fully apart in order to properly lubricate moving parts. I'll try the Mikro-Forum next to see if anyone there has experience with this....

MicroBob
Posts: 1625
Joined: Sun Dec 25, 2016 9:11 am

Re: carl zeiss jena coarse focus mechanism?

#5 Post by MicroBob » Sat Dec 29, 2018 7:34 am

PeterArmitage wrote: Nyogel 795A, is too light.
Some microscope stands have an adjustable coarse focus mechanism - you might be able to adjust it.
Coarse forus is not that important as you don't use it that much. As long as it is not too hard to move so the gears would suffer it might not be necessary to dismantle it completely. The fine focus has to moove very nicely because otherwise the tiny gears would break very soon.

Bob

MWK
Posts: 12
Joined: Sat Jan 11, 2020 8:31 pm

Re: carl zeiss jena coarse focus mechanism?

#6 Post by MWK » Thu Jan 16, 2020 3:22 pm

I dismantled one recently, let me know if you still need help with that.

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