There's one thing left to worry about. The left hand focus knobs are, for whatever reason, set in toward the centerline of the focus block about a quarter of an inch compared to the right. The coarse knob almost-- but won't quite-- clear the SZH's uniquely wide microscope body.
If only I had some roughly 80-mil plate with which to fashion some spacers! Oh right...
(/me fishes spacer pieces from previous adapter attempt out of the scrap aluminum pile)
OK! First I need a ring spacer to set the coarse focus knob further away from the centerline.
Done! Now, the fine focus knob needs to be set away as well.
I considered making a shaft spacer, but it will weaken the overall assembly. Instead, I heated the brass inset in the fine focus knob until the ABS softened, then pushed it in 80 mil. I did use a guide to make sure it pushed in straight and flat-- no wobbling allowed.
The fine focus also has a spring-loaded friction mechanism to add a little resistance to it drifting. One side is built into the knob, which I just moved out 80-mil. So I need an 80-mil spacer to take up the slack.
Don't worry, the hammer in the background is a specially designed precision optics hammer.
I've set myself three requirements for the focus block graft:
- No modifications whatsoever to the original SZH microscope body
- End result has to work exactly as intended. No half-functional hacks.
- The end result must look professional, bordering on factory quality.
My original plan: Remove the microscope body mount from the block's dovetail, cut the ring part off, machine the remaining bit flat and add some additional bolt holes to secure it to the SZH.
And that kinda sorta works!
Unfortunately, the remaining block is not quite deep enough for the adjustment knobs to clear, nor is it tall enough to reach all four mounting holes on the back of the SZH body. That means I need to machine a spacer that would have to bolt to the mounting block, then those two pieces could mount to the dovetail and the scope.
Then I thought 'what am I doing?', chucked it, and grabbed a piece of aluminum that's actually the right size to start with.
So let's do this part again.
Sadly, no Chinese manufacturer to date has cloned an SZH, but there are clones of other Olympus focus blocks.
None of these will fit as-is of course, the SZH is weird. But several look to be moddable with a little effort. So I chose a clone of a nicer Olympus coarse/fine assembly.
And now, a review of the FYSCOPE STEREO ZOOM MICROSCOPE COARSE AND FINE FOCUS ARM A4 76mm Size! ( Read more... )
I actually like my AmScope. It's not exactly precision-manufacture and god only knows what glass it uses, but it's durably made, fairly ergonomic, and works well for the price. Only one regret: The camera port is damned near useless.
For some reason, Chinese stereo scopes mostly appear to be clones of old, low- and mid-range Olympus designs. That planted the Olympus bee in my bonnet.
You've probably heard that Nikon is a world-class optics manufacturer that just happens to make cameras. Well, Olympus is a world-class optics manufacturer that just happens to make microscopes.
Looking for no-holds-barred top shelf stereo optics, the current top of the Olympus stereo line is the SZX12. Which is awesome and even broken surplus parts are so far out of budget it's not funny. Mostly the same for the SZX10, its slightly less featureful little brother.
But it turns out the very top of the discontinued predecessor line, the SZH10, is similar enough that it takes many of the same accessories and was every bit as good a scope. And the SZH10 was just a minor feature tweak of the earlier SZH.
And the SZH line is so gloriously 1980s. I mean, just look at this ad. It's not a stereo zoom. No, it's a *super* stereo zoom. And raytracing is involved somehow. And lightning. This here 'scope is obviously real wrath-of-god stuff.
Anyway, the rest is serendipity: There just happened to be enough cheap-ish parts on eBay to hopefully piece together a complete SZH with no major flaws.
Parts have arrived, so here we go...