xmj0001 What size counterweight should be used and where should it be placed on the counterweight bar since it wont be balancing the mount just keeping the mount from tipping over.
As usual, if you are using a tripod, draw a triangle on the ground connecting where the three legs sit on the ground. When you drop a plumb from the center of gravity of your mount and payload, the plumb needs to be inside this triangle for all Hour Angle and Declination angle of the mount. Preferably well inside this triangle.
It is often sufficient to just use rock bags (used by photographers to stabilize tripods) that also moves the center of gravity into this triangle.
https://www.amazon.com/Selens-Universal-Tripod-Stone-Bag/dp/B01GQ0FSZO
In my case, I use a RST-135 mount on top of a William Optics Mortar tri-pier, and I'd placed heavy weights (instrumentation box, counterweights from other mounts, bricks, concrete step stones, etc) on the crossbars of the tri-pier. If your tripod did not come with crossbars or a shelf, just get a rock bag. Tripods that are designed for astrophotography should have come with some means to weigh the center down.
Chen
