2 x OSMA 110mm Pipe Brackets (part 4S082)
I paid £4.80 for the two brackets. The bolts, glue and felt were found about the house.
A piggy-back camera adapter consists of a simple ring assembly that fits firmly around the telescope tube and a means to connect a camera to it. The few I have seen specifically for the Nexstar follow this basic concept and cost if not an arm and a leg then at least a small appendage.
I decided that it should be possible to construct a piggyback camera adapter from plastic pipe brackets used for securing rainwater downpipes and the like to walls. A visit to my local builder’s merchant provided the desired materials. These consist of two OSMA brand black pipe brackets for securing 110mm pipes, the part number is 4S082. The brackets are designed to fit tubes (pipes) of a diameter smaller than the Nexstar but they are sufficiently flexible to be bent to the desired curvature with little difficulty.
The basic idea is to join two brackets together to form the mount. Picture 1 shows the completed mount.
Picture 2 is a bracket before cutting and shaping so that it will curve 3 quarters of the way around the circumference of the Nexstar. Make the cut at point 1 and then soften the last half inch to bend outwards to form the first join point (refer to picture 1 to get the idea). Drill a hole to fit the bolt you have.
You now need to cut a section from the second bracket to form the remainder of the circumference. This is a little difficult and involves making three cuts. Cuts 2, 3 and 4 are shown on picture 1. Once this has been completed you need to bend the end over and make the hole for the second joint point. Also a holesneed to be drilled at the head end where it will be bolted on to the other bracket.
Picture 3 shows the second bracket cut to the desired length, bent to shape and drilled.
Picture 4 is a closeup of the bracket head showing how the two parts are connected with a bolt.
Once the two parts are joined the final act is to glue soft felt around the inner side of the ring to protect the Nexstar when the bracket is mounted on the telescope. This isn't strictly necessary but does add a small element of "quality" to the finsihed adapter.
The weight of the adaptor as built is 4.5 ounces (125 grammes). The camera with a 135 mm lens weighs 1 pound 15 ounces (840 grammes).