I originally used the Logitech C270 Camera with this arm:

https://www.printables.com/model/144327-logitech-c270-camera-mount-for-prusa-mk2s-and-mk3-/files

When I switched to a C615, I wanted to re-use the arm and mount.

The base of the C615 is quite heavy and caused the arm to wobble quite a bit so I found a guide to remove the foldable base (rotate the camera 90 degrees, perpendicular to the base, peel the cover sticker and unscrew)

Without the base, the camera didn't fit the c270 mount so I remixed this model to fit.

Uses an M4x30 screw and nut to attach.

Note that one side is chamfered to allow for rotation.