Parametric Articulating Arrm

This is an OpenSCAD parametric version of the excellent articulating arms started by doctriam in (https://www.thingiverse.com/thing:2448971) but in the style of Rockbert in (https://www.thingiverse.com/thing:2551878).

Because it is parametric, you can make it as long as you like, and make numerous other changes.