Here are pictures of the Nikon microscope focus block I'm using for macro stacking. I want to a add a step motor, and if I understand correctly, the best approach is to remove either the right or left fine focus knob, find the drive shaft hidden beneath, and attach a "shaft coupler" to either connect the fine focus drive shaft with a step motor, or (again with a shaft coupler) to attach a gear and then use a timing belt to drive the fine focus from the step motor.
My immediate questions are, "How the heck to I remove the fine focus knob? And if I do, what will I find--will it be a nice, clean drive shaft that I can couple to? Or will it be more complicated, and I'll find myself buying myself problems?" And perhaps most important of all: "If I attempt to remove a fine focus knob, do I risk destroying this excellent, buttery-smooth focus block?"
I have a number of Nikon microscope service manuals, but none contain dissasembly instructions for this particular focus block--which appears quite different in design from the models the service manuals that I have cover. I believe it to be from a Nikon Optiphot (with no extra letters or numbers), but don't know for certain. The Optiphots with extra numbers that I have seen have a different sort of focusing block handle.
Any advice is very welcome--I suspect that for some members of this community, taking apart a focusing block like this child's play. Sorry to admit that it isn't so for me. I have some ideas, but don't want to risk destroying a really nice focusing block when advice from those who know could save me a lot of pain.
Thanks extremely, in advance, to those who respond.
Photo of both sides of focus block. On both left and right, coarse and fine focusing knobs are visible. Left side fine focus is labled with a scale. Please note "holes" in fine focus knobs on both sides--more later on that.
![Image](http://www.photomacrography.net/forum/userpix/679_Both_sides_1.jpg)
Right side (non labeled) knobs of focus block--coarse focus is the big, outside knob, fine focus is the small, inside knob. How the heck to do I remove the fine focus knob on this side, and what will I find if I do? Would it be a useful drive shaft for connecting a step motor via a shaft coupler?
![Image](http://www.photomacrography.net/forum/userpix/679_Right_side_2.jpg)
Closeup of one of the "holes" in the fine focus knobs. Such a "hole" exists on the fine focus knobs on both sides of the focus block. Each hole appears to contain a brass construct of unknown porperties--I cannot discern if these brass constructs are threaded, hex-keyed, or whatever. Advice very strongly requested before I risk this nice focus block in disassembling it.
Many thanks,
--Chris
![Image](http://www.photomacrography.net/forum/userpix/679_CUright_side_hole_2.jpg)