1200 GTO counterweight shaft

Terry R. Friedrichsen <terry@...>

I was allowed to place an order yesterday for the 1200 GTO mount, so I'm
going over the A-P web site with a fine-toothed comb looking for other
stuff I should get with it.

I see that there is a "special" 26.9" counterweight shaft (M12661) men-
tioned as an available option. This raised some questions:

1) what is the length of the *standard* counterweight shaft?

2) what are the dimensions of the 10 and 18 pound counterweights?

I'm planning to put a 16" Ritchey-Chretien (or possibly the LOMO Hypergraph)
on this mount; consequently, I've ordered four 18 lb. counterweights and
one 10 lb. counterweight. I'm obviously concerned that 5 counterweights
will fit on the shaft.

I also have some of other questions:

a) A-P lists the capacity of this mount as "140 lb. instrument, depending
on length". Do they intend this 140 lb. to include the counterweights?
Or will the mount really carry a 140 lb. instrument plus over 100 lb. of

b) For astrophotography, would it be advisable to stay well below the 140
lb. instrument limit or is the rating conservative enough that the mount is
rock-solid even at the rated limit? (Yeah, aperture fever is causing me to
think of going to a 20" instrument :-)

c) I see folks here talking about using the polar alignment scope, but it
is not mentioned on the A-P web site (at least, not that I've found). Does
it come with one? Is it an option?

Thanks for any help.

Terry R. Friedrichsen


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