Astro-Physics counterweights are precision machined from 303 stainless steel. The weights slip easily onto the counterweight shaft and are secured in position with a large hand knob/brass pin assembly. The brass pin will not mar your shaft.
Keep in mind that you can adjust the position of the weights to counterbalance varying loads. However, the addition of a guidescope, camera and other heavy accessories may necessitate an additional counterweight. If you plan to mount your Catadioptric, Newtonian or any other scope, figure that you will need a counterweight total equal to approximately 90-125% of the weight of your tube assembly and accessories (large diameter scopes require a higher percentage).
Important Mount Balancing Note: Please read this document to understand the proper way to position counterweights when balancing your mount: Balance to Optimize Guiding
Below are the nominal weights and dimensions of our counterweight line.
Counterweights for 1.125" Shaft - 400, 600E, 800 and Mach1GTO mounts:
Use these dimensions to determine how many counterweights will fit on each shaft:
6 lb. Counterweight (6SLCWT) - diameter: 5", thickness 1.1"
9 lb. Counterweight (9SLCWT) - diameter: 5", thickness 1.8"
14 lb. Counterweight (14SLCWT) - diameter: 6", thickness 1.8"
Mach1GTO Counterweight Shaft (M8084-B) - usable length 13.675"
For 400, 600E and 800 mounts, measure the length of your shaft.