I bought the APM152ED a while back, and although I love the scope, it was causing a problem in my observatory because of how front-heavy it is. In order to balance it on my AP900GTO mount, I had to slide it quite far back in the rings, which left me very little room between the eyepiece and the observatory wall when observing in any direction except north (left in the pictures). I decided to add weight to the rear of the OTA. I ordered a ring to fit the OTA from APM, and a dovetail counterweight with two 3.5# weights from ADM. As you can see in the "before & after" pictures below, I was able to move the OTA about 8" forward in the rings, which gave me the clearance I needed from the walls. Luckily, the APM152 has a sliding dewshield, so there was no problem with roof clearance.
It's a little hard to see, but the new ring and counterweights are just in front of the focuser. Comparing the pictures, you can see how much the OTA was moved. Observing is now much more comfortable...
(and it looks better, too!)
Edited by J_D_Metzger, 16 March 2020 - 03:09 PM.