Re: ATM Ebony Star and Varying Turning Force

[AMaroney@sptimes.com]

> I noted this a few weeks ago just after my 'First Light' (alas not 
kosher Ebony Star but definitely good grade Teflon). 
> Looking at Saturn was a joy whilst Jupiter near the zenith became a pain 
after a while.

My $0.02...

This was probably due less to the bearing material and more to the weight 
of the focuser, eyepiece and finder all being on one side of the bearing 
(trunion) axis.  The heavy side of the tube. with all the hardware, is 
going to want to drop down.  Ideally the weight of the scope should be 
balanced across the trunion axis.  Since this hardware has a similar 
weight regardless of the size of the scope it has more of an effect on a 
smaller scope.

It seems to make sense that if the trunion were located at the midpoint of 
the balance (instead of midpoint of the tube), which would be towards the 
side of the focuser that the extra mirror weight opposite of it would make 
for a more stable Zenith position.  Has anyone confirmed this?