Re: Counterweight needs

Joe Zeglinski


One oversight I think, that Cassidy made was that he didn't account for the
weight of the counterweight "bar" itself, which is not insignificant. On my
AP900, that's another 10.5 lbs, considered concentrated at it's mid length.
So, it should be included in the counter balance calculations as well. Other
mount's may have lighter or heavier bars.


----- Original Message -----
From: "Rick K" <JunkMailGoesHere@...>
To: <ap-gto@...>
Sent: Sunday, September 16, 2007 12:00 PM
Subject: [ap-gto] Re: Counterweight needs

Hi Alan

To do some calculations based upon the weights and moment arms of you
components, check out Robin Casady's web site:

Do not forget to add in the weight of the support rings and plates for
each configuration. Note also that mounting the refractor piggyback is
going to present a huge moment arm on whatever is holding it up. Some
beefy (heavy) rings such as Parallax are going to be required.

While you are there, check out the counterweights he sells. While the
AP counterweights are nice, in my opinion, the Casady counterweights
are much easier to use. Nicely radiused edges (smooth curve, no sharp
angles) and the absolutely super spring loaded lock-down knob
assemblies which keeps the lock-down pin out of the way are excellent
selling points. Otherwise, both are nicely machined stainless pieces
with brass inserts to stop marring of the counterweight shaft, and
both look great.


--- In ap-gto@..., Alan Voetsch <alanv12952@...> wrote:

Hey all,

The 1200 has been ordered from AP, and the 12" LX200R OTA also
(Company 7). Both should
arrive sometime next month.

Most other items i plan to buy used or fabricate locally. The CWs
can be made by a fellow
local astronomer and I wonder if anyone can give a reasonable
guesstimate on how much
I'll need. That OTA is 37 pounds, I'll guide off axis with only a
35mm camera body and an
ST-4 to add to the load. I am also considering a tandem arrangement,
or piggyback
situation for the FS-102. Will 60 pounds (3X20) of weights cover this?



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