DSLR rig mount for Luxpad with ball joint

I bought this nice LED video light called Luxpad 22 which is really nice and cheap. To improve it I already made this barndoors (https://www.thingiverse.com/thing:2125573). Now I wanted to mount it on my DSLR rig. The orginal mount ist for 3/8 inch skrews or the flashlight hotshoe. At the pad itself has also a flashlight hotshoe.

I decided to create a rig mount with a ball joint to be more fexible. It consits of a hotshoe with a threaded bolt, a screw nut to thighten the hotshoe to the pad. A