Asking for help - fixing/alignment of a Zeiss condenser rack

[Hobbyst46]

Hello all,

Raising and lowering of condenser rack on my Zeiss GFL often becomes problematic, it feels either like too high friction or too low friction, the rack is stuck or is inappropriately loose. Which of its various parts should be adjusted and in what order?
The photos below show a front view and left side angle view of empty rack.

(1) The focusing knob of the pinion, (1') the counterpart of 1 - end of 1, (2-4) screws that fix the condenser holder piece to a dovetail-rack beam,
(5) condenser carrier, (6) an inner part of the knob 1.
Note that 1' and 6 are not the two ends of the same piece, their rotations are independent of each other and of the knob 1 itself.
All these parts are metal, either brass or steel.

I would appreciate very much advice on which should be tightened, which should be adjusted to a certain extent, and in what order.
How to assemble the mechanism and make it work.
I would appreciate also information about manuals for maintenance of this unit.
Thanks in advance for help.

[MicroBob]

Hi Doron,

here are three pics of a Zeiss-Winkel - GFL I have as a basket case in the cupboard. It will be similar but not identical to your microscope.
I think the dampening is just a case of clean guides with the proper grease. You would need grease with medium dampening properties. I think it was in this forum that Molykote 111, a silicone grease, was mentioned. I bought some and it feels right. It is easier to get than the usual instrument greases.

On some Zeiss West instruments I dismantled I found thin aluminium foil stips as distancers. They adjust the play in the dovetails and between cog and rack.

Bob

[Hobbyst46]

Thanks Bob!

Yes, my condenser rack is the same as the one in the photos you show. Except that mine has no shims or spacers as far as I can see. Just the "original" brass parts (sometimes shims are original as well...). I would hesitate to add any shims without intimate familiarity with the rack mechanics.

However, I will get Molykote 111 and try it.

[Micro-Bob]

The only place to put additional spacers would be between rack and dovetail. The rack would be closer to the cog and so there would be some additional friction. Zeiss used aluminium foil, e.g. 0,03mm. It is more important not to remove or crumple any existing foil strips.

Probably cleaning and greasing alone will do the job.

[Hobbyst46]

Thanks Micro-Bob for the information. I will avoid any change of spacers for the time being.

[imkap]

This post is old, but better to have it all in one place

I didn't succeed in removing the gear from the holder, I wanted to do that as it has some free movement, which is not a game changer but somewhat annoying...
There is a small peg holding the thing inside (near number 1 on the image) I suppose when I remove it I would be able to disassemble it fully... Not sure how to do it, if anyone did it please share...

Thanks