Configurable vertical spool holder

I was impressed by benjaminbellamy's spool holder but I wanted to make some modifications. In fact I wrote totally new scad files with almost all options configurable (you can change all sizes, bearings, count of arms and so on). My holder is bigger and has interchangeable centering ring so a lot of spools can fit it. But the idea of design was not changed.
This spool holder can be used with a lot of spool's types, it only need to change centering ring. You can print it "as is" or change almost everything in configuration file. You should generate or print centering rings for each of your spools.
My holder is printed with PLA and the base is 20cm (almost 8") diameter.