From: "Orion105" 
To: 
Reply-To: "Orion105" 


I have completed the build of the OTA of my 12.5" f/5 Dob.  I am now
finalising the alt bearing size and position.  I would like to use a range
of EP's that include my 20mm Nagler which weighs over 2 lbs and also some
regular Plossls.  The calculated CG position varies over a range of close
to 2" depending on which EP I will use!

So, for the bearing size and position what should I assume?

I could position the bearing for the mid point of the cg range.   Would
static friction be enough to stop the scope tipping both up and down
depending on EP used?

Or I could position the bearing for the lighter EP and place removable
weights on the UTA for the time I use the big Nagler?

What's your advice?

Ado

--- BBBS/NT v4.00 MP