Re: Refractor on top of OTA ok? AP 1100 GTO Mount

David Enck

Ok, thanks George, that helps narrow my options!


On Dec 2, 2020, at 12:52 PM, George <george@...> wrote:



I do not recommend it due to the enormous moment arm.   Sticking the 20 lb. refractor on top, way out from the center of gravity is like adding 40-50 lb.






George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...


From: <> On Behalf Of David Enck
Sent: Wednesday, December 2, 2020 2:28 PM
Subject: [ap-gto] Refractor on top of OTA ok? AP 1100 GTO Mount


Hello AP Folks,

I  currently run a Meade LX850 14 inch SCT  ota on my 1100 GTO. It handles it beautifully for visual and photography.. I am  looking to possibly add a Takahashi TSA 120  APO to the mix. My 14 inch weights about 75 pounds with all the gear on it. The new TAK 120 is 15 pounds bare, so about 20 with rings and a dovetail bar..  If I  choose to mount it on top of the OTA will it be ok? I  have about 118 lbs of counterweights available to me to use to counter balance it.

I am looking  to  go this route vs side by side  mounting as it will be more difficult to  balance the dec axis by myself with this much weight involved trying to slide the saddle plates back and forth. There is a  huge weight difference between the two scopes..

Thank you for you  advice and thoughts!  


Join to automatically receive all group messages.