Articulating Tablet Wall Mount

A simple wall mount composed of two arms, a coupler, and adapter for another mount.
Here is a link to the exact mount I made the adapter for: https://goo.gl/RxKdhw

This thing is quite bulky, but it's pretty durable. If anyone wants to improve the design, I've included an F3D file, in addition to STEP files.

I'm going to eventually make a retractable mount using rubber bands.

Additional materials include only nuts and bolts. Sizes are:
4 x 5/16-24 in. or M8x1.25
1 x 1/4-20 in. or M6x1