Minimalistic single screw motor mounts

I found the various motor mounts projects available either bulky or too fragile.
I've made this one that is meant to be fixed to the cf tube using a single 2mm screw without sacrificing the sturdiness.
Motor hole pattern is the standard 12mm/16mm found in almost any 18xx class of motor. I'm using this with DYS 1806. It is made for 12mm outer diameter tubes.

*Update 30 Sept:*

added Inventor part files and an experimental/untested 22xx version with 16x19 hole pattern.
The 22xx versio