Re: Balance Procedure

Joe Zeglinski

Hi Roland,

This is good news - I was becoming concerned about "meticulously"
rebalancing the counterweights, every time I crossed the meridian. Indeed, the
AP900 is a superb design, and even more so, from what you say about the
rebalance issue.

One question:
You use the phrase "8 lbs out of balance", do you mean 8 inch-lbs?
Being "out of balance" with an 8 lb camera overhand at 6 inches is different
from the same weight overhanging 2 feet away. Could you be more specific about
the "moment arm" on the OTA imbalance you are describing?

Actually, it would be interesting, if someone there could do a bit of
testing in this regard, on various "moment-arm measurements", before you would
consider the AP900 or AP1200 seriously out of balance, for the expected
performance. For that matter, before you would consider possible damage to the
worm gear. That might provide a good rule of thumb which could be applied to
any OTA overload situation, to specific AP mounts.

I suppose one might say that the imbalance on any mount has reached a
maximum, if the clutches won't hold, but some might torque down the clutches
too tightly, even with a wrench, in order to avoid having to shift the

Thanks for any further info,

----- Original Message -----
From: <chris1011@...>
To: <ap-gto@...>
Sent: Monday, April 23, 2007 1:04 PM
Subject: Re: [ap-gto] Balance Procedure

In a message dated 4/21/2007 8:52:34 AM Central Daylight Time,
drichey@... writes:

What's the procedure for rebalancing. If I have very good polar alignment
and a good
pointing accuracy, but need to loosen the clutces and reblance the load due
to adding
equipment, how do I maintain my pointing model.
Your pointing model is not affected if you loosen the clutches to rebalance.
On the other hand, why do you need to do this? I image all the time without
ever rebalancing. It is not really necessary. I have been as much as 8lb out
balance on both 900/1200 mounts, and recently ran 6lb out of balance on my
little bitty Mach1 mount. The tracking/guiding was spot on perfect.

Roland Christen

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