I usually purchase my filament in 1 kg reels, but recently had to purchase some in coils, some of which were 5 pounds.  I had printed a two part reel in the past to deal with smaller coils, like this:

 

 

It turns out that this reel was not large enough to keep all of the filament in a 5 pound coil in place.  Also, while this reel works OK for small (light) coils, with 5 pounds of filament the rotation resistance was excessive.

I needed to design a spool with a larger diameter and a smaller centered hub. And rather than designing two different parts, I decided to design a part that could be printed twice to make up a spool.  This is what  I came up with:

 

 

 

 

 

 

 

 

 

 

You may notice in the final picture that I had to saw out the four places where the part transitioned from smaller to larger diameter.  I have revised the design to avoid this problem next time.

Also, as wonderful as this approach is in theory, mating the two parts is not easy when their alignment is obscured by a 5 pound coil of filament.  Given that I have about 18 hours of print time into these two parts, I may have to live with the inconvenience for a while