Post subject: Question on an AO 570 for the experts
Posted: Wed Apr 01, 2020 5:54 pm
Valued Contributor
Joined: Sun Mar 11, 2007 10:03 pm Posts: 341 Location: San Diego
As I mentioned to some of you at the GO dinner in Tucson, I picked up an older American Optics microscope earlier this year for a steal (under $300). However, it was in rough shape and needed quite a bit of work to be functional again. I have been slowly dissembling, cleaning, lubricating, etc. the scope and have come to a point that assistance would be greatly appreciated.
The remaining issues are:
There were small red rubber seals at the base of each ocular which were falling apart. Where can I find replacements and how do the oculars come out?
Is the base of the head supposed to have a threaded lens or is this just for the addition of a doubler?
Lastly, is there a way to correct the image offset?
Here is the full scope in its current state after cleaning and refreshing.
_________________ Paul Mattlin Senior Manager, Online Education Division
* My posts are my own and do not reflect the opinions or policies of my employer
The only red seals I know of on these are plugs to keep dust out of the oculars when there are no eyepieces in there--I assume that's not what we're dealing with though. Could you point out whwre on the ocular/eyepiece assembly they were? The oculars do not come off easily, as they are held in place from below. I wouldn't mess with them unless it is strictly necessary. The threads are just to accept a 1.5x, 2x, 0.5x, ring light mount or protective lens shield. No problem if there's nothing mounted.
Image offset should be adjustable to slme extent. The focus mount is held in place with four bolts. I suspect you can loosen the bolts a bit, shift the focus mount around a bit to get it centered and then retighten them.
The Gemolite Mk V is a thing of beauty and very solidly constructed. With no offense meant to your employer they just don't make 'em like they used to.
Post subject: Re: Question on an AO 570 for the experts
Posted: Wed Apr 01, 2020 8:34 pm
Valued Contributor
Joined: Sun Mar 11, 2007 10:03 pm Posts: 341 Location: San Diego
These are the remains of the seals, o-rings, gaskets or whatever they were originally...
They were located here
Unfortunately, the focus mount bolts appear to be somewhat self-aligning. They tighten right back into the same position without allowing for much movement, if any.
No offence taken on the equipment. I spent over ten years using the Mark VII as a student, in the trade and as an instructor. The older analog models are what I am accustomed to and prefer. Don't get me started on the lighting options available these days...
_________________ Paul Mattlin Senior Manager, Online Education Division
* My posts are my own and do not reflect the opinions or policies of my employer
I think those might just be rubber bands. Sometimes they end up on oculars to add extra spacing on eyepieces, though it looks like yours has AO originals that shouldn't need anything like that. Either way I haven't seen them on a stereo star before and thry aren't on the one exMple I have hanging around here.
Too bad about the focus mount. It does seem like a rather significant offset, more than you'd expect from normal variations. Everything looks ship-shape externally too, so no easy explanations like the head not being quite seated right.
Post subject: Re: Question on an AO 570 for the experts
Posted: Wed Apr 01, 2020 10:36 pm
Valued Contributor
Joined: Sun Mar 11, 2007 10:03 pm Posts: 341 Location: San Diego
Thanks for the help. This scope is for home use and I'm likely to be the only person who ever uses it, so the offset isn't the end of the world. With the iris open, it is much less noticible. If it really bugs me, I'll eventually just shim the focus mount a bit.
_________________ Paul Mattlin Senior Manager, Online Education Division
* My posts are my own and do not reflect the opinions or policies of my employer
Usually when I'm making adapters I make the holes a bit overlarge so I can do fine adjustments to the centering, but it does seem to be common for the gemolites to be a little off center one way or another. If you have four bolts tightening them down is enough to maintain the position even if the bolts have some horizontal wiggle room in the hole--that's what they did on the Diamond Grader scope, though they apparently had to change what head they were putting on that a couple times so that was probably less their design choice and more having to fit different bolts in the hole. So if it really bugs you you can always take the focus mount off and widen the mounting holes a little bit, though it's less ideal to have to do a permanent change like that.
As you say, it's unlikely to cause any real problems in use. At low mag it's only over by a few percentage, at high mags it'll be way out of focus when the gem is in focus.
edit: by the way, good luck having the overhead lamp diffuser intact. They crack or get lost pretty easily.
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