Carl Zeiss OPMI1 Microscope - Drifting of the Focus Knob

[cor9brg]

Hallo everybody!

I am now the proud owner of a Carl Zeiss Microscope (OPMI 1). It definitely does change the quality of watchmaking. However I noticed that whenever adjusting the left focus knob, there was some residue (small particles) on my workbench below that knob. I unscrewed it and found a lot of old "gunk", which I cleaned with a dry soft rag. I then noticed that the "friction washer" has started to deteriorate (I have uploaded some pictures). After cleaning, I reassembled the knob and now noticed that there is a drift downwards of the micrscope head even after firmly tightning the knob. Probably need to find a new "friction washer"...?

Question: Anybody with experience on such issues? Spare parts for a ca. 60s microscope still availbale? I did manage to find some documentation, but until now not helpfull...

Pages 7) and 8):

https://archive.org/details/manual_Zeiss_Opmi_1_FC_S100_Floor_Stand_Service_Manual_DE/page/8/mode/2up

Would apreciate any feedback... Thanks!

[Neverenoughwatches]

Same make as my surgeons microscope, is the dial below the focus knobs for the adjustable objective lenses ? The open tube in the arm on mine is for the light source and the other small knob is for coloured light filters. 

I had a similar issue with the eyepiece holders, when i adjusted the eye distances black/brown debris would fall onto my bench.

Edited January 5 by Neverenoughwatches

[AndyGSi]

Can you confirm which part no. this is? 19?

If it is that part then it shouldn't be too difficult to make a replacement.

[cor9brg]

@Neverenoughwatches: Yes, OPMI stands for Operation Microscope...

The dial below the focus knobs is for the adjustable objective lenses (0.6, 1.0. 1.6, 2.5 and 4.0). Mine came without the light source, but I have just installed a LED-ring light and covered up the hole (The original and replacement lamps seem to be very expensive!). 

@Neverenoughwatches:

 - Have you done some preventive or corrective maintenance on your microscope?

- Have you had any other issues or had to purchase any spare parts?

- Do you also have the same base / stand as mine

Edited January 5 by cor9brg

[cor9brg]

24 minutes ago, AndyGSi said:

Can you confirm which part no. this is? 19?

If it is that part then it shouldn't be too difficult to make a replacement.

The knob is on the other side (left), so I assume part no. 38 but I am not sure yet. No. 19 and 38 should then be symmetric but in the parts description they are diferent:

19: 000000-0086-446, 14+0,1X20-0,2X0,5 CZN790 TEFLON

38: 303651-0167-000, Intermediate ring

[AndyGSi]

So from this photo which side is the knob that you're showing?

[cor9brg]

Just now, AndyGSi said:

So from this photo which side is the knob that you're showing?

Yes sorry, this picture is taken from the back. The knob here on the right side, but in the service manual page 7) on the left side. The single knob is where I have the issue (above picture on the right)

...

[AndyGSi]

Something doesn't look quite right here unless the damaged part is what's called the fibre cone 39.

Is there another washer 40 that goes on the shaft before this knob?

[cor9brg]

10 hours ago, AndyGSi said:

Something doesn't look quite right here unless the damaged part is what's called the fibre cone 39.

Is there another washer 40 that goes on the shaft before this knob?

Yes, there seems to be a mismatch between my microscope and the documentation (maybe not 100% the same). Mine is only OPMI1 without floor-stand and the documentation describes the OPMI 1 FC with floor-stand...

I will remove the focus knob again, try to dissasemble it to better understand its construction and compare it to the available doumentation...

Edited January 6 by cor9brg

[Neverenoughwatches]

11 hours ago, AndyGSi said:

So from this photo which side is the knob that you're showing?

This is the adjustment for the focusing play, when this knob isn't tight the head drifts down when you're looking through the eyepieces. 

12 hours ago, cor9brg said:

@Neverenoughwatches: Yes, OPMI stands for Operation Microscope...

The dial below the focus knobs is for the adjustable objective lenses (0.6, 1.0. 1.6, 2.5 and 4.0). Mine came without the light source, but I have just installed a LED-ring light and covered up the hole (The original and replacement lamps seem to be very expensive!). 

@Neverenoughwatches:

 - Have you done some preventive or corrective maintenance on your microscope?

- Have you had any other issues or had to purchase any spare parts?

- Do you also have the same base / stand as mine

The flip lenses are the same as mine,and with the 12.5 eyepieces so that should in therory provide a range of 7.5x to 50x . Though there is another lens at the bottom which is probably a barlow that quotes f-200, so not entirely sure how that all equates. But with the 6 objective I get 50mm field of view. I've left mine well alone, whatever the debris was stopped after a couple of days use and it hasn't affected how it works. The only issue I do have is the light has 3 brightness settings, anything above the lowest setting and the halogen bulb gets head very hot until i get around to changing the bulb out for an led. The bulb has an odd fitting .

[cor9brg]

3 hours ago, cor9brg said:

Yes, there seems to be a mismatch between my microscope and the documentation (maybe not 100% the same). Mine is only OPMI1 without floor-stand and the documentation describes the OPMI 1 FC with floor-stand...

I will remove the focus knob again, try to dissasemble it to better understand its construction and compare it to the available doumentation...

Well the plot thickens :-))))

I disassembled the focus knob (see pictures) and found a completely different construction as seen in the documentation (mine is probably older). I found a broken screw, am missing the rest (thread) of the broken screw (probably somebody has been in there before), a washer and a strong spring inside... Back to google to search for documentation that describes my construction...

[cor9brg]

3 hours ago, Neverenoughwatches said:

This is the adjustment for the focusing play, when this knob isn't tight the head drifts down when you're looking through the eyepieces. 

The flip lenses are the same as mine,and with the 12.5 eyepieces so that should in therory provide a range of 7.5x to 50x . Though there is another lens at the bottom which is probably a barlow that quotes f-200, so not entirely sure how that all equates. But with the 6 objective I get 50mm field of view. I've left mine well alone, whatever the debris was stopped after a couple of days use and it hasn't affected how it works. The only issue I do have is the light has 3 brightness settings, anything above the lowest setting and the halogen bulb gets head very hot until i get around to changing the bulb out for an led. The bulb has an odd fitting .

Yes, I purchased a ring-LED light on Amazon as mine was missing the original setup:

https://www.amazon.de/-/en/gp/product/B0CQSKNJCX/ref=ewc_pr_img_1?smid=A1OGL1VB75X46Y&psc=1

The knob that you have highlighted, if I understood correctly, is for the fixation of the tilting of the microscope head (angle). The other two focus knobs, one the left and the one on the right are used to fix the Z-Axis (drift) of the microscope head. If you turn them both simultaneously inwards you increase the friction and thus the fixation. If you turn them both simulatenously outwards you decrease the friction and have a lighter focus knob operation, but run the risk of the downward drift... I unfortunately cannot verify this correclty as mine is currently not working properly... 

[Neverenoughwatches]

22 minutes ago, cor9brg said:

The knob that you have highlighted, if I understood correctly, is for the fixation of the tilting of the microscope head (angle). The other two focus knobs, one the left and the one on the right are used to fix the Z-Axis (drift) of the microscope head. If you turn them both simultaneously inwards you increase the friction and thus the fixation. If you turn them both simulatenously outwards you decrease the friction and have a lighter focus knob operation, but run the risk of the downward drift... I unfortunately cannot verify this correclty as mine is currently not working properly... 

Apologies yes you're correct screwing the focus knobs in together tightens up the focusing operations, I discovered it by accident about a year ago when i noticed the head drifting down when viewkng. If you can't get the original parts I'm sure you could have them made up. When you have it all fixed you will love it, its a great piece of kit with super quality optics, I was guessing at around the 1960s. The stand and boom arm are so well made I sometimes wheel mine around the room to where ever I'm working.