I know, I know, send it back to the factory or to a repair center. But that
costs money, and I don't learn anything if I do that.

I have a couple of 0.7 to 3.0 Bausch & Lomb microscope pods that are messed
up - - one white one that requires eye convergence for less than a foot away
to superimpose the images, and a black one I just bought that is okay
horizontally but has a vertical offset. They don't look like they were
dropped or anything, but the left eye optical path seems different from the
right eye path. It may be my imagination, but the right side of each
instrument looks good.

I think just about any technician or engineer who needs to work with today's
surface-mount technology needs a good zoom microscope, so there must be a
lot of them around. I paid $15 for the black one today, complete with stand.
Okay, I should be able to afford some repair expense to put this thing back
in shape, but what's it going to go for after it's fixed - - $100? Can I get
it repaired for $85? I don't think so. And I Google-searched all over for
some hints as to how to adjust or repair this brand of microscope, but
there's not a single post that I could find that was any help. I guess all
the repair techs have signed a non-disclosure agreement or something.

Getting down to business, I opened up my black $15 microscope and found a
series of mirrors in the section that allows interpupillary adjustment, and
two movable lenses on each side in the zoom section. The mirrors all appear
to be positioned by contact with machined surfaces on pivoting aluminum
castings. It doesn't look like these can move around unless one breaks loose
from the glyp they put around the edges of the contact areas. Looking into
the empty eyepiece holes, the left eye sees a bright elongated spot (8 to
10% of aperture area) outside the aperture at about 10:00 at all zoom
settings that is not present in the right eyepiece hole - - looks like a
sneak path or a chip out of a mirror. The image offset of the left when
eyepieces are in place is about 1/6 of a field diameter low compared to the
right, and could be converged with eyesight set for 6 ft away, if the
vertical offset were not present. This offset is exactly the same at all
magnifications. The white microscope behaves exactly the same at all
magnifications, also.

In the zoom section, turning the zoom control rotates a pair of cam shafts
grooved for pins that drive Nylon pads along guides. Each lens is fastened
to its Nylon pad by a couple of screws, and it appears possible to adjust
lens tilt by loosening the screws a bit. I have resisted the temptation to
see what happens when the screws are loosened, but is this the only
adjustment for optical convergence we have? It looks pretty sloppy and
difficult to control.

So have any of you dug into your microscope and figured out how to fix it?
Do any of you with B&L training care to guide an old EE to make something
good out of the junk he finds at a flea market?

Thanks for all your help,

Chuck, w6pkp

On Mon, 2 May 2005 12:15:51 -0700 "Chuck Olson"
wrote:

So have any of you dug into your microscope and figured out how to fix it?
Do any of you with B&L training care to guide an old EE to make something
good out of the junk he finds at a flea market?

I wish I knew how this was done, but I don't. I DO know that the
company I used to work for once sent out their scope to be realigned
to a local camera repair shop. They apparently had some kind of laser
alignment system which helped this process.

You might try calling such a place just to get an idea of cost.

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Jim Adney
Madison, WI 53711 USA
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