[ATM] Re: ATM Balance

["Tom and Beth" <tomandbeth@theriver.com>]

IIRC, this whole thread started off with a way to guesstimate the center of
balance
of a telescope tube, and now we've gone on to casting weights and such.

Yeeech. how about engineering the scope such that weights aren't needed?

Some of you have spreadsheets to calculate center of balance (CoB), but are
you
considering the loads along three axis? A tube has length (X axis), debth (Y
axis)
and height (Z axis). Consider, if you will, the effect of your focuser with
one of these
kilogram or more eyepieces. If your spreadsheet is only looking at the
balance load
along the length of the tube (X axis), you may not be correctly balanced  as
the tube
transitions from horizontal to verticle due to the imbalance in axis Y
and/or Z. And then
 in order to fix this problem, many of us add weight which re-balances the
tube on one
axis, only to throw one or both of the other axis off. Arrrrrgggghhhh, we
keep fighting
against ourselfs!

Let's face it. How many of us position (as an example) our finderscope to
balance the
Y and Z load of the focuser and eyepieces? Sure you can balance the X axis
loads rather
easily, with no more than your telescope tube and a broom handle on the
floor.

Balancing the tube in 3 axis has been on the list off and on for a few
years.Perhaps some of
those new to this passion aren't aware of this? Other things taken for
granted by some of us "old
timers" are things like Bob May mentioned;that the size of the altitude
bearing and spacing of the
teflon (for those making a Dob) has an impact on how much of a weight
differntial you can have. Mel's
Trilateralist article in S&T encourages us to think of new ways of fighting
the balance beast such as
elliptical altitude bearings.

Just an encouragement to all of us, we don't need no stinkin counterweights.

Tom
Tucson, AZ

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