50's Leitz lab microscope restoration

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

tbrown - 27 May 2006 20:43 GMT

Hello all,
I have recently aquired a 1953-ish Leitz lab microscope that needs a
serious clean up. I envisioned removing the obvious screws from the
knobs that would then slide off so I could clean them in solvent or the
ultrasonic cleaner I wish I had right about now. Having bought a new
screwdriver that fit well, I removed the screws on the main focuser,
micro focuser, and x-y slide holder. None of these knobs slide off, so
I assume they are press-fit. If anyone could point me to the magic
"Leitz microscope disassembly" web site, that would be great. I'm
betting that does not exist, so any personal experience would work
wonders as well. Things I know I need now:

- A wide variety of difference sized flat-blade screwdrivers or bits
(preferred)
- Really tiny gear pullers
- Owner and service manuals for Leitz microscopes
- Patience
- Alternate ideas for a thorough cleaning

Please post replies as I can't read that email anymore.

Thanks,

Scott

Reply to this Message

Kevin Cunningham - 28 May 2006 20:01 GMT

> Hello all,
> I have recently aquired a 1953-ish Leitz lab microscope that needs a
[quoted text clipped - 20 lines]
>
> Scott

Great questions! I make my living repairing microscopes so let me weigh in
with my opinions.

Solvents are important. Just about anything with a high vapor pressure
makes a good solvent. However a lot of high vapor pressure solvents will
try to kill you, ether and zylene come to mind. I use alchol, acetone,
water based cleaner (Sparkle, Windex) and heptane. All are very safe and
easy to find. I put them in a Menda bottle so when I push the top of the
Menda I get just a little.

For good tools try either P.B. Bauman (Swiss) or Wiha screwdrivers up to 5.5
mm, Excelite metric Allen wrenchs, Allen, Inc. Allen wrenchs and Nicholson
files. You'll need a full set of files from 6" Nicholson to watch makers
files. You'll also have a few tools to make. Buy an inexpensive small
screw driver and an inexpensive needle nosed pliers. Both will have to be
filed down so that the screw driver can be your prying tool and the pliers
can be your ring removing tool. Go to a watch makers tool store and get a
diamond handling tweezers, you will use these constantly. You just don't
need a gear puller, I never used one. There are a bunch of tools that are
helpfull but these will get you going.

For glass cleaning, use Kim-wipes, there soft, cheap and easy to get. Never
clean glass dry, never. Always use water based cleaner at least, usually I
use water based cleaner and alchol. I mix them on the Kim-wipe. You may
need some two headed Q-tips, when you go into an objective these work real
well. One side is great for cleaner and the other side is to wipe with.

What you really need is good lubricants. Try Dow-Corning, you will need a
heavy lub like Dow-Corning 111 and a light one like Dow-Corning 43 (?). For
a light lube Amsoil makes a red lub that works great. Please note, all of
these are synthetic, thats what you need. Don't even think about an oil.

You might find an E. Leitz manual for this instrument, anything can happen.
Service manuals were just parts drawings, those can be helpfull but
sometimes they could be very confusing. This instrument was made for one or
two months year, they always changed. The best thing is to make notes and
take pictures.

The best way to get a profesional maintenance job is to hire a profesional
microscope repair tech. It would cost a lot less and take very little time.
Check to see the companies around you. We work in the South East, if we can
be of any help let us know.

Kevin Cunningham
SMS

Reply to this Message

tbrown - 29 May 2006 00:27 GMT

Thanks for the thorough answer Kevin. I live in the Chicago area, so
I'm sure there is a microscope service outfit nearby. For the moment,
it is a labor of love and is not testing my patience, so I'll plod
along. I removed the objectives from the turret and removed the optics
package from the carriers of each objective. Those I cleaned in mild
detergent with a toothbrush. I am happy with the results - it looks
like new. I didn't see any reason to take the turret apart. Much of
what needs to be cleaned is the schmutz (aka finger-cheese) from the
knurling of the knobs. If I don't need gear-pullers for the knobs, how
do they come off? Those that I tried do not budge, even with the big
screws removed. I am thinking of covering the face with electrical
tape, filling the fillet area of the shaft-to-knob interface with
Vaseline, and tipping the stand on its side so I can clean it with the
same detergent and toothbrush setup without getting water where I don't
want it.

What degree of disassembly would you suggest? I'd like to give the
stage and slide holder a bath. The rack seems fine. The main focuser is
stiff, but moves very slowly with firm torque. That seems like a good
balance between workable and focus drift. The fine focus is very
smooth. Can you tell me if the substage screws are painted in place? It
is hard to tell, but the paint on the screw heads looks as though they
were never tightened very much.

Is there a dealer you can recommend for Bauman or Wihl tools? Some of
the screw heads seem like they are really nuts, with the screw shaft
going right to the center of the nut. This requires a screwdriver with
a relief filed out if the center to pass the screw shaft. I see this on
the dial that adjusts the inter-pupillary distance on the binoculars
and agian on the condenser. Are there any surprises to be found here?

Thanks,

Scott

Reply to this Message

Kevin Cunningham - 29 May 2006 17:21 GMT

> Thanks for the thorough answer Kevin. I live in the Chicago area, so
> I'm sure there is a microscope service outfit nearby. For the moment,
[quoted text clipped - 30 lines]
>
> Scott

Scott, Glad you're enjoying your self! Most of the problems with
microscopes is not dirt, there isn't a lot of dirt in labs, its bad
lubricant. It sounds like the lubricant in the 'scope is gone. You need to
take *everything* apart, relubricate and reasemble. You'll need to get the
tolerances right but you can do that my feel.

Removing the fine-coarse mechanism depends on which of the fine-coarse
mechanisms Leitz put on this instrument. Probably you have the single knob
focus system on this one. Please send me a picture to my web mail or post
it here (smskjc@mindspring.com).

Your technique for doing the coarse-fine is horrendous. DON'T DO IT!
PLEASE! When I see a picture I can tell you how to do it. Also never use
the term "Vaseline" with the term microscope. It causes all kind of
problems. My teacher will get in his Mercedes, drive over and rip my lungs
out.

You can get Wiha screwdrivers somewere in Chicago, I got mine at a couple of
hardware stores in Atlanta, look at their web site. P. B. Bauman can be
bought from them over the web or use their web site to find a hardware store
to buy from. Actually there are 3 kinds of straight bladed screwdrivers,
the Wiha web site goes into horrendously boring detail on all of them.
Leitz would paint the screw heads, wait for them to dry and then install
them, ah, the good ole days.

What you need for the screw you discuss is not removed with a screw driver,
thats were you need to modify a needle nosed pliers. Use a Nicholson file
or a grinding wheel to get the pliers to a fine point, then insert it and
turn.

Good Luck!

Kevin Cunningham
SMS

Reply to this Message

Edward Hennessey - 30 May 2006 19:59 GMT

> Hello all,
> I have recently aquired a 1953-ish Leitz lab microscope that needs a
[quoted text clipped - 16 lines]
>
> Please post replies as I can't read that email anymore.

Scott:

A great source for fine precision hand tools is
www.brownells.com

Regards,

Edward Hennessey

Reply to this Message

Natural Science Forum / Physics / Optics / May 2006

50's Leitz lab microscope restoration