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From: Lee Martin (no email)
Date: Tue Aug 03 2004 - 20:45:07 EDT
Joel, I am not so sure about some of your suggestions, my comments below.
----- Original Message -----
From: "Joel Jacobs" <>
To: <>
Sent: Wednesday, August 04, 2004 2:56 AM
Subject: Re: on washing sextants
> Courtney,
Sometimes it pays to
> remove the aft leg which will allow the index arm to move backwards off
the
> arc. There maybe some kind of a stop which has to be removed.
On my 1988 SNO-T the index arm sits within the frame and it is impossible to
move it off the arc.
Take the index
> arm and move it all the way to the back of the arc. In a CHO-T the
underside
> of the cylinder in which the tangent screw is housed has a slot which is
> wide enough to see the teeth of the screw.
Not on my SNO-T...the drum completely "seals" the tangent screw in all
positions of the index arm. It is clear that is the purpose of the
design....the drum completely encloses the tangent screw and the drum fits
snugly on the arc, all to prevent the ingress of dirt. The only way to get
at the tangent screw is to unscrew the 3 screws holding the drum onto the
index arm, and remove the drum....something I would not want to do often.
I have always found a RTFM to be a useful thing to do when these sorts of
questions arise. In this case, the SNO-T manual suggests the only
maintenance necessary is a careful brushing of the arc after each use (brush
supplied) to remove all particles of grit and salt. And a very occasional
lubrication of the arc with the lubricant supplied (no idea what it is).
Clearly, any but the lightest lubrication will pick up grit and salt......I
have never lubricated mine, prefering to rely on stringent cleanliness. It
seems to me that one would only access the tangent screw or internals of the
drum when normal maintenance had failed, or wasn't carried out at all.
Trying to wash the drum in situ on the arm doesn't seem very useful to me,
because there is no way to flush water in and out of the drum, to carry the
dirt and salt away.
The manual has nothing to say about preserving the eyecups. I have used
occasional talc, which I suspect is what was placed on them in the
factory.In any case, I suspect the eyecups might be relatively easy to
replace at a camera/binocular store.
Lee Martin
>
> ----- Original Message -----
> From: "Courtney Thomas" <>
> To: <>
> Sent: Tuesday, August 03, 2004 10:52 AM
> Subject: Re: on washing sextants
>
>
> > Joel,
> >
> > I have a CHO-T with the barrel enclosed tangent screw.
> >
> > How do I properly gain access to the tangent screw ?
> >
> > Also, what should be done to preserve rubber eye cup pliability ?
> >
> > Appreciatively,
> >
> > Courtney
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