I am using 32mm /1.25inch tubes to hold my filament spools. I got some spools with 53mm/2inch inner diameter. With this hub adapter they fit perfect.

There are some filament spool hub adapters but I can't find one to simply plug into the filament spool having the right size.

So I made this Universal Spool Hub Adapter for the Customizer. You can not only change the dimensions, you can also define or remove the collar or chamfer if you want. There is automaticly a 1mm backlash added to the inner diameter to make it easy rotating on the axle/tube (Advanced Settings). On the outer diameter is also an extra mm added to fit it tight on the spool (I called it "Arm Compression" in the Customizer).

I have uploaded the 25mm version for the original Prusa i3 HEPHESTOS holder. Many thanks to Runkel for making and testing it. After seeing fcartegnie clever parametrized remix I have added three new versions of the 25mm adapter with only 4 arms.

There seems to be a rendering problem inside the Customizer, I can't find the reason. But the resulting STL files are perfect.

Here are my other printer parts you may also interested:
http://www.thingiverse.com/wstein/collections/my-printer-parts

I used on PLA:
0.3mm layer thickness
25% infill

Versions:

V1.4: inner hole fix (see http://www.thingiverse.com/thing:1151473)
V1.3.1: Bug fixed for latest customizer
V1.3: Customizer creation failure fixed. Some smaller issues fixed. More slider used. License updated to CC BY-SA.
V1.2: part handling optimized
V1.1: new star shape