Well, you are hanging that extra 20 kg out there a good 300mm over where it would be "normally" so it acts like twice that.  But the mount should handle it.  I had a 300mm F7.2 Newtonian weighing a solid 45 kg when completely configured for use on my 1200 and it did just fine with that long load.  I'd be more concerned about flexure and I'd slow the slew rate down to 600x.  Of course, you can always try it and see what happens.

Jeff

On Fri, Feb 5, 2021 at 8:28 AM Geert <geert.vandenbulcke@...> wrote:

Hello,

 

A question: I have an AP1200GTO on a fixed concrete pillar in an observatory.  Would this handle the following load: a 300 mm f/4 newton with a weight of approximately 20kg (including camera) and piggy-back a 150mm f/7 triplet refractor, all in all also 20 kg.  Total weight of 40kg is well within specs but I am concerned about the longer arm by putting the heavy refractor piggyback on the newton?!  Side-by-side is no option, also very difficult to balance.

 

Thanks for your thoughts,

 

Geert