Re: [ATM] How to find Centre of Gravity of an existing telescope

["Bob May" <rmay@nethere.com>]

Actually, the falling off problem only happens when the tilt gets
to be too much for the scope's saddle.  A lower COG will tend to
keep the scope from faling off only because the COG isn't beyond
the base of the scope until it gets further tilted over.
The biggest problem tho with the COG of the scope not being in
liine with the axis of rotation of the platform is that the motor
will be loadesd going one way, like the starting zone when the
COG is too high and then unloaded when getting near the end of
the travel for the tracking time as the weight drives the scope
further towards the endpoint of travel.  A COG that is lower than
the axis will, of course do the opposite with the motort holding
the platform back at the beginning and working hard at the end of
the travel time.
Don't worry about the balancing point being an inch or two off as
there won't be muh force on the platform unless you're talking
about a really large scope.
For an indication of how little power that you really need, go
look up the weight of the Hale telescope and the tiny motor that
is used to drive it around.
Bob May
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