“In Soviet Russia, Microscopes”.. er wait.
I inherited this from my dad. It has quite a few condenser attachments as well as a nice set of sample slides.
Some research on its serial number (N773137) implies this means it was manufactured in 1977.. so the 3137th microscope of 1977?
The thing is built like a tank, but over the years, the grease (apocryphally “Russian Tank Grease”) used to lubricate it had turned into some sort of glue, so none of the focus controls worked any more. However, the optics were perfectly fine.
I wanted to fix it. This involved careful disassembly and bagging of all the screws and tiny springs I discovered. I also tried to record how the parts went back together for reassembly (this sort of thing is so much easier with mobile phone cameras!).
I carefully removed all the old grease/glue with white spirit, and then used Isopropyl Alcohol to remove any trace of that.
But what to replace it with? Some internet research pointed me at this page, where someone else had done something similar. Importantly, they gave recommendations on what grease to use on fine machinery: I don’t want to have to do this all again next year (I’ve heard similar problems from CuriousMarc on Youtube).
For the fine gearing/moving parts, I ended up getting a “Nye Hobbyist Lubricant Kit” (also: my search history is now totally screwed) since Nye seem to be well regarded. This kit has a high and low viscosity oil as well as a grease. I mainly used the high viscosity oil and grease, but the low viscosity oil was handy to “unfreeze” a stuck part I had previously failed to remove (the condenser attachment ring).
I acquired it from here. It was not cheap, but I now have a lifetime’s supply of fine machine lubricant for other restoration projects:
There were also some small springs that I wanted to coat with grease to prevent corrosion. I decided to get a tub of really cheap “bearing grease” for this purpose.
After reassembly, the microscope works really well: I don’t even have any screws/etc left over! I could now actually get on with the project I wanted to use it for.