Parametric MasterSpool with thread

Hello, I'm using a Prusa i3 MK3 3D-Printer and refill filament from http://www.dasfilament.de.
The refill filaments saves plastic and shipping weight/costs. To use it, I will need a master-spool. I found several, but no one met my requirement, e.g. customizing the rod hole diameter or using less material and printing time. So I decided to make my own thing, starting with an other thing: https://www.thingiverse.com/thing:1782398
My thing is fully reconfigurable using openscad (http://www.openscad.org), so it's usable not only as a master-spool and there is no need to glue anything.
You can change anything for your needs and make a remix of it.
I hope it`s for everybody useful. Please give me a comment, if you have some questions, remarks, suggestion or issues.

I wish you happy printing.

09/24/18 Some small improvements made, 1. additional text on the flange of Part B, 2. Better visibility in the OpenScad CSG compiler (fast preview), 3. fix some older little bugs.

Note: If you are using OpenScad for customizing, find the path to the library file "threads.scad" and complete the path in the file "parametric_master-spool_with_thread.scad", "line 7: include <C: .... threads.scad>;". Otherwise you will get an error while compiling because the file can not be found.
WARNING: Can't open include file 'C:/..../threads.scad'.
WARNING: Ignoring unknown module 'metric_thread'.
WARNING: Ignoring unknown module 'metric_thread'.