Originally, this mount is designed to attach my EZVID camera (C6CN) to the same tube where my monitor's VESA mount is attached, although it can be used on any type of tube. 

The design is made in OpenSCAD, and if opened with this program, the tube radius and clamp orientation can be changed from the Customizer window. 

I have also included some STL files ready for printing with some common tube sizes: 12mm, 14mm and 16mm