This is intended to hold a cable going off the back edge of a table, preventing it from falling off under its own weight, while allowing it to be pulled forward or free of the holder easily.

Unfortunately, the cam is is easily jostled loose, or pushed up by the cable's rigidity. Further work is needed. Most obvious directions to improve it (e.g. adding a counterweight to the cam and reducing its range of motion) would either interfere with removing the cable or require printing a much larger cam.

Some of the code might be reusable for other applications: the cam and its pivot and stop pin, and the pre-bent C-clamp structure.

The hardware used is UNC (North American) #6 screws, nuts, and washers.