----------------------------

#21884 May 4, 2008

Hi all

I am on the waiting list for a 1200GTO mount. I am trying to

calculate approximately how much counter weight I will need and at

what distance.

To do this I need to know:

(1) Distance from RA axis to where the counterweight shaft screws in

(2) The distance from the RA axis to the telescope mounting plate

I assume that how far out of balance the mount is without the

counterweight shaft is too small to be significant.

The length and weight of the counter weight shaft are available on

the web site.

If my memory of high school maths is valid, I can then calculate with:

(M1 * D1) + (Mn * Dn) = (Telescope mass * Telescope distance)

Does anyone know if the 1200GTO is the next stand to go into

production? :-)

Thanks

John Murphy

----------------------------

#21885 May 4, 2008

There's a spreadsheet in the files section that has all the

dimentions you need. IIRC it's called Lat Calc.

Robin Casady also has a great article on CWs.

--- In ap-gto@yahoogroups.com

wrote: >

> Hi all

>

> I am on the waiting list for a 1200GTO mount. I am trying to

> calculate approximately how much counter weight I will need and at

> what distance.

> To do this I need to know:

>

> (1) Distance from RA axis to where the counterweight shaft screws

in > (2) The distance from the RA axis to the telescope mounting plate

>

> I assume that how far out of balance the mount is without the

> counterweight shaft is too small to be significant.

>

> The length and weight of the counter weight shaft are available on

> the web site.

>

> If my memory of high school maths is valid, I can then calculate

with: > (M1 * D1) + (Mn * Dn) = (Telescope mass * Telescope distance)

>

> Does anyone know if the 1200GTO is the next stand to go into

> production? :-)

>

> Thanks

> John Murphy

>

----------------------------

#21886 May 4, 2008

The spreadsheet looks very useful. Unfortunately, despite there being

lots of dimensions in the spreadsheet, I cannot find the ones I

need... I guess that the dimensions I am after are not dependant on

the latitude setting (the affect of any angle will cancel out).

Thanks

John Murphy

--- In ap-gto@yahoogroups.com

>

>

> There's a spreadsheet in the files section that has all the

> dimentions you need. IIRC it's called Lat Calc.

>

> Robin Casady also has a great article on CWs.

>

>

> --- In ap-gto@yahoogroups.com

> wrote:

> >

> > Hi all

> >

> > I am on the waiting list for a 1200GTO mount. I am trying to

> > calculate approximately how much counter weight I will need and

at

> > what distance.

> > To do this I need to know:

> >

> > (1) Distance from RA axis to where the counterweight shaft screws

> in

> > (2) The distance from the RA axis to the telescope mounting plate

> >

> > I assume that how far out of balance the mount is without the

> > counterweight shaft is too small to be significant.

> >

> > The length and weight of the counter weight shaft are available

on

> > the web site.

> >

> > If my memory of high school maths is valid, I can then calculate

> with:

> > (M1 * D1) + (Mn * Dn) = (Telescope mass * Telescope distance)

> >

> > Does anyone know if the 1200GTO is the next stand to go into

> > production? :-)

> >

> > Thanks

> > John Murphy

> >

>