I actually replaced the rack, but the problem returned a few weeks later.
I found that no matter how hard I tightened the rack, it would slide back
away from the pinion with time (and not very much time). Apparently, the static
friction against the wall of the scope is insufficient against the shear force.
I thought of making one with a tighter tolerance on the through holes for the
screws which hold it. Our machinist said that this will not work, because
there has to be some play in those holes in order to position the rack
correctly. I thought that a drop of superglue might help, but I am reluctant
to do something that might be irreversible. This problem has rendered the scope
useless, and is driving me crazy, because I dont know how it ever worked,
and why Zeiss made something like this.
--aryeh
Don Elsmore wrote:
> Hello Ian,
>
> Seen this problem a lot with 100 series.
> You need to replace the brass rack as the teeth are usually
> damaged which causes this problem. These were available from Ziess.
>
> Regards
>
> Donald Elsmore
> President/Field Service Engineer
>
> Aventeck LLC
> 10112 Owen Brown Road,
> Columbia, MD 21044
> Cell: 443-745-2087
> Fax: 443-367-0187
> www.aventeck.com
>
>
>
>
> > Date: Fri, 27 Feb 2009 12:09:32 +0000
> > From: [log in to unmask]
> > Subject: Re: problem with Zeiss Axiovert 100 series scopes
> > To: [log in to unmask]
> >
> > Aryeh Weiss <[log in to unmask]> writes:
> >
> > > The Zeiss Axiovert 100 series scopes use a rack and pinion arrangement
> > > to move the turret in the Z-direction. One two of our scopes the rack
> > > (ie the toothed rod that meshes with the axle which the focus knob
> > > rotates) comes loose and fails to mesh properly with the pinion, so
> > > that the turret falls and cannot be raised. No matter how hard I
> > > tighten it when I reseat it, it slips out of position. This appears to
> > > have happened to a second Axiovert 100 that we have.
> > >
> > > My question is: have other users on this list had this problem, and if
> > > so, how was it resolved? I reported on this in 2001, and it worked for
> > > some years, but now the problem has worsened and my attempts to
> > > tighten the rack do not work for more than a few weeks.
> >
> > I have seen this several years ago. The situation was worsened by the
> > rack and pinion then not meshing properly and shaving falling off the
> > rack so that the microscope was not able to focus properly at some
> > positions even the the system properly tightened again. We had the
> > scope serviced by Zeiss who replaced the mechanism. I'm not sure if
> > they replaced both parts or just the rack.
> >
> > Ian
>
> ------------------------------------------------------------------------
> MSN NZ Travel Get inspired - dream, research, plan and book your next
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--
Aryeh Weiss
School of Engineering
Bar Ilan University
Ramat Gan 52900 Israel
Ph: 972-3-5317638
FAX: 972-3-7384050
Israel Society for Microscopy 2009 meeting website:
http://materials.technion.ac.il/ism/ISM2009.html
|
