Double Screw Pen Cup

I based this on an existing scad file I found on the internet for dual screw(https://www.thingiverse.com/thing:4721889). 

A pen cup is made up of screw, a left and right nut, and optionally a top nut.

Also there is the possibility to print the screw as vase and bottom to allow the “main” body to be printed in vase mode.  

I have included several examples and a link to original openscad source in github: https://github.com/mproctor13/double_screw_pen_cup