Leitz Diaplan - Problem with the focuser knobs

[N3ptune]

Hello everyone, I am starting this thread in hope of finding a cure for my Microscope.

(First this is my introduction here:)
viewtopic.php?f=4&t=14988

***
I am going in right ahead with my question because I can't wait to know more about this. This is my microscope, the Leitz Diaplan



And I wish to talk about the problem with the focuser, it's very stiff and it's hard to move the stage up and down.. After an exam of the situation and involving the disassembly of the instrument, I have isolated a problem related to the coarse knobs.. either left or right, I can't tell but it's about to seize.

I am searching for some solutions, anything that can be done to restore a nice smooth focus. These are a couple of pictures, the exterior gears are in good condition.





This video illustrates the problem with the knobs..
https://www.youtube.com/watch?v=8x6dOphYRJA

Can anything be done about this?

Thanks.

[zzffnn]

Pipette around 6-8 drops of mineral spirits onto gears and junctions. It may just take a few minutes to dissolve the sticky old grease. Mine did yesterday.

[N3ptune]

Ok

I don't have mineral spirits now but I'll buy some later today and try it on the gears and inside of the mechanism.

Thanks for the suggestion along with the heating solution from @DrPhoxinus.

[N3ptune]

Pipette around 6-8 drops of mineral spirits onto gears and junctions. It may just take a few minutes to dissolve the sticky old grease. Mine did yesterday.

I poured a couple of drops of spirits as you suggested and it worked!! The focuser is now 90% more smooth then it was of not 95% wow it's amazing I am super happy about this.

See the evidence:
https://www.youtube.com/watch?v=mp4DWnFVVhs

Now I am letting it dry a bit, when it's dried, should I pour a drop or two of 3 in 1 oil each side, to smooth and protect even further?

Thanks a bunch again!

[zzffnn]

It depends on how much damping you want.

If you use too much solvent and do not re-apply the right lubricant, you may end up having somewhat loose gears.

Mine is somewhat loose (not having enough damping) now, as I use white petroleum jelly (which is very very light grease); I am fine that way but most people may not like it that way.

Other members can recommend you the right damping grease. I forgot the spelling of that brand; it sounds like "Nee" (probably Nye, but I don't know the right type to use). I should order some myself, once I find out.

[Hobbyst46]

Other members can recommend you the right damping grease. I forgot the spelling of that brand; it sounds like "Nee".

"The knights who say Nye"
Nyogel 767A is a damping grease. Somewhat thick, but works fine for heavy brass loads.

[N3ptune]

It depends on how much damping you want.

If you use too much solvent and do not re-apply the right lubricant, you may end up having somewhat loose gears.

Mine is somewhat loose (not having enough damping) now, as I use white petroleum jelly (which is very very light grease); I am fine that way but most people may not like it that way.

Other members can recommend you the right damping grease. I forgot the spelling of that brand; it sounds like "Nee" (probably Nye, but I don't know the right type to use). I should order some myself, once I find out.

Ok it's good to know about the damping factor, oil is a bad idea then. I would have made a serious mistake by putting oil in.. Wow! not at all what is required to do, glad I asked.

Basically you use regular pharmacy Vaseline?

Other members can recommend you the right damping grease. I forgot the spelling of that brand; it sounds like "Nee".

"The knights who say Nye"
Nyogel 767A is a damping grease. Somewhat thick, but works fine for heavy brass loads.

Ah thanks, I was told about the expensive grease previously, now I know the name of it.

Let's say I order a tube of Nyogel, I need to disassemble the to knobs in order to put it inside directly,.

Meaning that I need to disassemble this bellow and the other side which is different a bit. I am scared to do it.. the left knob is a very strange mechanism.

[N3ptune]

I am rebuilding the microscope right now and the stage is now reinstalled, it works A1 up and down.

But there might be an issue now. It's possible for me to level the microscope itself then level the the stage horizontally, the X axis or the larger side of the stage. But for the Y axis, there is no angle level adjustment for that.. and by installing the level, it's not levelled.

Is this a big deal? should I attempt to have a perfect level there? (Not sure if it's even possible)



***
Secondly I started the cleaning the condenser lens because they are covered with an amount of dust and I can see those at the eyepiece. There are large particles on the part of lenses that is inside of the condenser.

I tried to remove the plate A, thinking that the lens B would come out with it but not at all, from that side of the condenser, I need a special spanner wrench to unscrew the lens B. I don't have one right now, I will build one tomorrow.


Then I tried to access the interior of the condenser from the other side, but I don't have the right screw driver to unscrew the cover E. I am not sure if I should remove the support F instead of E.. to clean under the lens G and H. (And probably B also)

Finally lens H, that one has some hardened grease on it, could >90% isopropyl alcohol do the trick for cleaning that ?

I need advices on cleaning the condenser, not to damage anything.


Thanks.

[zzffnn]

You may want to start a new thread or change the thread title to ask about the Leitz condenser.

I like using this lens spanner for microscopy items (such as condensers ad objective kenses): https://www.amazon.com/dp/B0014Y4K16?ps ... ct_details

This screw driver set has many different tiny bits that may be useful for microscopy repair (again I like mine): https://www.amazon.com/dp/B07DHHMMVC?ps ... ct_details

MIneral spirit may work better than 91% IPA in some cases. Xylene is toxic but very powerful solvent; I use it when I have to (only when IPA or mineral spirit does not work).