Re: Larger "diameter" Counterweights for AP-1600 ?

Joe Zeglinski

Thanks Howard, You are correct,

I did get my "Latitude problem" reference, reversed. The weights hitting the pier, would be more likely for a concern with mounts used at LOWER latitudes, closer to the equator.

So, Chuck might have a problem using heavier, "larger diameter", counterweights, at the upper part of the bar. Only solution then would be to use steel encased lead filled cwts .

As a side note, to using something for counterweights, "heavier than lead" - the early NASA Lifting Vehicle M2-F2 (precursor of the Space Shuttle) - needed to shift the centre of gravity, and the engineers briefly ... and incredibly ... considered surrounding the pilot's cockpit with "Depleted Uranium, as ballast, which is much DENSER than lead", to save space - a method, commonly used to balance aerospace vehicles. (ref. Wingless Flight, pg 78). That idea was quickly squashed, by the three main test pilots who didn't like the idea of cooking their feet in radiation - and maybe by the test pilot's wife. :-)


-----Original Message-----
From: Howard
Sent: Thursday, May 03, 2012 6:13 PM
To: ap-gto@...
Subject: RE: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Hi Joe,

I'm assuming you got the latitudes backward in the second paragraph ... Anyway, it is a moot point with the 1600 since the azimuth adjuster is in the back of the mount.

Mag. 7 Skies!

Howard Hedlund
Astro-Physics, Inc.
Phone: 815-282-1513<>
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From: ap-gto@... [mailto:ap-gto@...] On Behalf Of Joe Zeglinski
Sent: Thursday, May 03, 2012 4:28 PM
To: ap-gto@...
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Hi Chuck,

If at all possible ... it is best to AVOID using extension bars. I have
been advised by an expert, that he keeps his stack of cwts as close to the
upper bar as possible, and even retained his old, shorter, AP-1200 cwt bar.
He says that with the large mass of cwts down the bar, their "inertia" can
affect the "responsiveness", of fine guiding corrections.

Of course, this won't pose a problem for those at low latitudes, but
those in higher latitudes may have no choice but to use extensions, since
the cwt diameter can clip the mount post-meridian, especially the mount AZ
Adjuster knob, which sticks out a bit further, beyond the pier perimeter.

Some things to consider, before going for lighter weights further own the
bar, for the same leverage.
Joe Z.

-----Original Message-----
From: divenuts
Sent: Thursday, May 03, 2012 4:46 PM
To: ap-gto@...<>
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Don't forget you can get an extention cwt bar, which cost much less than the
weights. If the 1600 couldn't use the 1200 weights..that would be a deal
breaker for me.


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