olympus KHC disassembly question

[aquaculture]

Hi, I am disassembling an Olympus KHC microscope to free up the mechanisms; the grease is very stiff. I got everything apart but one of the larger focus knobs. It is retained by a slotted nut which would normally be removed by a bladed spanning lens ring tool but the nut is installed upside down so there is nothing for a tool to grab. Additionally, it looks like there is a pin driven up into one of the slots to prevent the nut from turning. There doesn't appear any way that the pin could have been inserted from the bottom.

Anyone taken apart something like this?

If this question should go to a microscope maintenance forum, are there any suggestions?

Many thanks, in advance!

[PeteM]

Not sure about the KHC, but the central shaft and drive pinion can be removed from either side in some microscopes. Perhaps it will withdraw if you free up the other side of the focus assembly??

Picture might help others with a KHC recognize what you're facing.

Worst case, you might be able to get a few drops of solvent in from the other side, followed by a couple drops of pure light oil, to free up the old grease. Time, gravity, and rotating the mechanism to work the solvent and then the oil in might get it to move freely enough.

[aquaculture]

I worked on this problem for hours, then made my opening post. Then an idea came and I got the last bit apart. Both the nut and the knob unscrew from the shaft. I carefully gripped the pinion gear and unscrewed both at the same time. The knob is not threaded but has the pin which engages one of the slots of the upside-down nut. Now it's clean and re-lube time!

I still thank you for your response.