Skadis/Lack Hinge Mount for Small Arm System

I created this hinge primarily to support adjusting the positioning of the arm for my Yeti Blue mic.  I have a Lack shelf with Capita legs that used to be a monitor stand.  Now it's sort of a catch-all that the mic is mounted to using the RostaP small arm system.

A note about the lack mount:  Lack shelves are hollow.  I used toggle anchors for 3 of the holes.  The fourth hole screws into the wood that's at the edge of the shelf.  It's sturdy enough for what I need and I didn't want the screwy bits of a clamp hanging below the shelf.

The hinge pin/bolt is a scaled version of doctrium's articulating wall mount.