Wet lens holder (caddy) - tripod screw mount

This is a simple and safe holder for a wet lens to be attached below the camera case using a tripod screw. A step-up adapter ring to the desired size is needed (approx $1 on ebay).
The current design is for a 52mm ring, change the scad file for other sizes.
The concept is similar to this: http://www.camerasunderwater.co.uk/lenses/adapters/lens-caddy