Re: Nikon Labophot fine focus problem

On Dec 22, 2:27 pm, Too_Many_Tools <too_many_to...@xxxxxxxxx> wrote:
On Dec 22, 10:24 am, Kevin Cunningham <sms...@xxxxxxxxxxxxxx> wrote:



On Dec 21, 11:52 am, Too_Many_Tools <too_many_to...@xxxxxxxxx> wrote:

On Dec 20, 7:22 pm, Kevin Cunningham <sms...@xxxxxxxxxxxxxx> wrote:

On Dec 20, 6:28 pm, Too_Many_Tools <too_many_to...@xxxxxxxxx> wrote:

On Dec 20, 4:20 pm, David Ellis <dpel...@xxxxxxxxxxxxxxxxxxxxxxxxx>
wrote:

In the 3rd Millenium, on Sat, 20 Dec 2008 14:16:48 -0800 (PST),
Too_Many_Tools <too_many_to...@xxxxxxxxx> submitted this:

On Dec 20, 3:03 pm, David Ellis <dpel...@xxxxxxxxxxxxxxxxxxxxxxxxx>
wrote:
In the 3rd Millenium, on Sat, 20 Dec 2008 06:08:03 -0800 (PST), Kevin
Cunningham <sms...@xxxxxxxxxxxxxx> submitted this:

Too_Many_Tools wrote:
I have in front of me a Nikon Labophot. Its stage slowly creeps
downward due to gravity...with the fine focus knob slowly turning in
response to the stage creep. Is there an user adjustment that I can
make to correct this problem? Also what causes the focus assembly to
do this...obviously it did not do this before.

I would like to find a copy of the user and accessory documents that
apply to this instrument....can you point me to where one might find
it?

Thanks for whatever help you can offer.

You shouldn't have to do a thing.  Just reach over to the right hand
side coarse focus then move slightly back.  There is friction ring
there that has to be set properly, the right tension will stop the
downward creep.  A bit to much makes the mechanism feel tight.

Kevin Cunningham

Later models did have a tension ring but it was just for the coarse
focus. The fine focus will drift if there is not enough pressure from
the washer  on the fine focus knobs  - no matter how much tension is
put on the coarse.
--
Dave Ellis
Fireblade cbr900rry- Hide quoted text -

- Show quoted text -

I can believe that there are differences during the production run of
a scope.

Where EXACTLY is this tension ring?

A picture would help.

TMT

Between the coarse knob and the body. If you can't see one you haven't
got one.
--
Dave Ellis
Fireblade cbr900rry- Hide quoted text -

- Show quoted text -

Thanks...this particular version of the Labophot does NOT have a
separate ring between the coarse knob and the body....the coarse knobs
on both side are all one section.

Do you think that the friction ring was a later addition to the series
to address the problem of stage creep?

TMT

Changes are made in just about every production run.  The Lab changed
a lot over its many prod. runs.  David is right, I had to get my
thinking had screwed on.

If you want to be a repair tech I can go through what you have to do
to re-lubricate the fine focus, that should be done occasionally.
Synthetic greases last longer, that is why I use them.

Now what you need to do is get a good 1.5mm Allen head and loosen on
of the screws holding only one of the fine focus knobs.  Make sure the
knob is loose.  Keep the Allen head in the screw and push it inwards
with the Allen head.  At the same time push on the other fine focus.
Tighten the Allen screw finger tight.  Don't over tighten or this will
be a problem later.  There is a flat spot on the fine focus shaft,
make sure the screw goes in the flat spot.

Let us know how it goes!

Kevin Cunningham
SMS- Hide quoted text -

- Show quoted text -

Thanks for the help...I think I can handle it.

It is interesting to note that this scope did not have a compression
washer in place when it was disassembled...apparently missing in
action.

In interest of education, is the fine focus of the Nikon Labophot/2
series typical of fine focus mechanisms of the current generation of
scopes available today?

Thanks

TMT,

Well, yes and no.  Back in the ole days there were all kinds of focus
mechanisms from the AO 10 to the Leitz research.  Now pretty much all
systems use a three gear coarse-fine system.  It's relatively cheap to
make and it works across the range of objectives.  Things like the
Zeiss three ball system work well if maintained properly but if you
attach them to a motor drive system there can be some slippage so now
Zeiss has the three gear system.

The no part is that more and more microscopes are equipped with
electronic systems using a motor drive.  They work better and they are
getting cheaper to build.  Soon that will be the way of things.

Merry Christmas, Happy Holidays!

Thanks,

Kevin Cunningham
SMS- Hide quoted text -

- Show quoted text -

Interesting evolution...and alarming also.

I have seen many older scopes that work decades after their purchase.
The ones I see failing almost always consist of whatever electronics
they may have.

Do you think we will see today's microscopes working fifity years from
now?

It's odd but understandable, today's microscopes have to do work that
was impossible 10 years ago. Right now a department that doesn't have
a confocal - multi-photon is just not doing what it should just as in
the late 70's a department would have one big Zeiss for photo's.

While a lot of these generation one instruments won't be used by
amateurs later ones will. Confocals, multi-photons, evanescent waves,
Hell's Theorem, electronic drive inverteds, etc. will wind up on the
used market in the future. The electronic drive units will be a lot
better, when controlled properly, than the units built in the past.
Previous units were like old pocket watches, nice to look at, neat to
have for three days then a darn pain to live with.

Collectors will collect all kinds of neat stuff. The question for
collectors is how many of these are there? For amateur users the
question is what bang for what buck? These instruments have tons of
bang, now if the bucks are right.....

I and every other repair tech has come up with tons of ways to fix
mechanical instruments, this has been going on for a while. As these
new instruments break, just like an instrument, we will have to come
up with new ways to fix them. I'm gonna have a ton of fun!

Thanks,

Kevin Cunningham
SMS
.

Relevant Pages

  • Re: Nikon Labophot fine focus problem
    ... response to the stage creep. ... side coarse focus then move slightly back. ... of the screws holding only one of the fine focus knobs. ... Tighten the Allen screw finger tight. ...
    (sci.techniques.microscopy)
  • Re: Nikon Labophot fine focus problem
    ... response to the stage creep. ... side coarse focus then move slightly back. ... of the screws holding only one of the fine focus knobs. ... Tighten the Allen screw finger tight. ...
    (sci.techniques.microscopy)
  • Re: Nikon Labophot fine focus problem
    ... response to the stage creep. ... Now what you need to do is get a good 1.5mm Allen head and loosen on ... of the screws holding only one of the fine focus knobs. ... Tighten the Allen screw finger tight. ...
    (sci.techniques.microscopy)
  • Re: Nikon Labophot fine focus problem
    ... response to the stage creep. ... Now what you need to do is get a good 1.5mm Allen head and loosen on ... of the screws holding only one of the fine focus knobs. ... Tighten the Allen screw finger tight. ...
    (sci.techniques.microscopy)