This is an adapter that fits two concentric pipes and mounts onto the shutter of a Princeton Instruments Pylon CCD camera, helping prevent stray light from reaching the sensor. The larger pipe outer diameter is ~114 mm (~4.5 inches) and the smaller concentric pipe outer diameter is ~48 mm (~1.9 inches).
The CAD files were designed with a single-extruder 3D printer in mind, so there is no need for support material. The .stl files were generated with OpenSCAD, and .scad files are included so you can customize them if need be. Because of the limited size of the the printer I used, I divided the adapter and spacer into three identical segments. Files for these are attached as well.
If possible, this should be printed in black plastic to minimize internal reflections. Unfortunately, I was almost completely out of black plastic, but I was able to print in white and used a sharpie pen to darken all exposed internal surfaces.