The pier should not be dead center in the observatory with a fork mount; for the
LX90, the
offset of the pier should be about 10-12" south of center. The overall weight
(torque) of
the scope leaning out from a wedge does not change, provided that the length of
the fork
arms do not change. If you put the pier dead center in the room, you will be
very cramped
to the north side of the pier.

Dr. Clay
_____
Arkansas Sky Observatories
MPC H45 - Petit Jean Mountain South
MPC H41 - Petit Jean Mountain
MPC H43 - Conway West
http://www.arksky.org/

----- Original Message -----
From: "stargazerlx90" <stargazerlx90@...>
To: <lx90@yahoogroups.com>
Sent: Saturday, July 11, 2009 8:57 AM
Subject: [lx90] Re: Pier offset


> Hi Fernando,
> Thanks for your response.
> But i thought the weight of the scope on any wedge will be the same no matter
how long
> the gap is between the centres of a wedge, and providing enough reinforcement
is made to
> fully compensate for the slightly extra length of the wedge i really can't see
it being
> a problem?
> This will mean the pier remains dead centre of the observatory with no offset
needed
> just in case i should have any clearance problems if I'm correct.
>
> Jeff.
>
>
>
> --- In lx90@yahoogroups.com, Fernando Campuzano <fcampuzano25@...> wrote:
>>
>> Hi Jeff.
>> Just a doubt. Why do you want the centre of the DEC axis being alligned with
the centre
>> of the pier?. Shouldn't be the ideal situation with the gravity centre of the
whole
>> setup (scope and wedge) being alligned with the pier? The centre of the DEC
axis will
>> be just the centre for the balance of the OTA with all of its accesories
(cameras,
>> guide tube, counterweights,etc). The extra weight from the fork arms, wedge
and the
>> base of the scope would be tensioning the attachments bolts of the wedge to
the pier,
>> and maybe introducing some pier flexure..?
>> Fernando
>>
>>
>>
>>
>>
>> ________________________________
>> De: stargazerlx90 <stargazerlx90@...>
>> Para: lx90@yahoogroups.com
>> Enviado: sábado, 11 de julio, 2009 10:30:13
>> Asunto: [lx90] Re: Pier offset
>>
>>
>>
>>
>>
>> Hi,
>> Just wondering if anyone can help with this info i need as i don't have my
scope with
>> me at the moment.
>> What I'm actually looking for is a distance between the centre of the
pier/wedge
>> mounting bolt to the centre of the DEC axis when the angle is set to a
Latitude of
>> 37.3, the idea is that the Dec axis automatically centres over the pier
centre when set
>> at this Lat.
>>
>> If i then construct a wedge with these measurements it will mean i don't need
to have a
>> pier offset i think, am i correct with this assumption please any takers?
>>
>> Thanks all.
>>
>> Jeff.
>>
>> --- In lx90@yahoogroups. com, "stargazerlx90" <stargazerlx90@ ...> wrote:
>> >
>> > Sorry that should read "so the 'pier' is still centred in the observatory"
.
>> >
>> > Jeff.
>> >
>> >
>> >
>> >
>> > --- In lx90@yahoogroups. com, "stargazerlx90" <stargazerlx90@ > wrote:
>> > >
>> > > Would someone be able to work out what the pier offset is for a Lat of
37.352?
>> > > I want to costruct a wedge for a 12" lx90 but make the offset distance
correspond
>> > > to the centre of the mounting bolt so the scope is still centred in the
>> > > observatory. Does this make sense?
>> > > I think it was 13 3/4" at that lat from memory but could be way out!!
>> > >
>> > > Many thanks.
>> > >
>> > > Clear skies.
>> > >
>> > > Jeff.
>> > >
>> >
>>
>>
>>
>>
>>
>>
>>
>> [Non-text portions of this message have been removed]
>>
>
>
>
>
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