Spool Holder/Roller

Simple, but solid spool roller using smooth idlers, which can be used directly to roll the spools on and have a wide (9mm) space to accommodate different size spools.  The design is a bit overkill probably, but it is strong and sturdy.  Best of all is simple and requires no additional prints for rollers.  It works well with cardboard and plastic spools.

It works with any 200mm diameter spools (may work with others, but haven't tested) that range from 50-70mm in height or thickness.  

BOM: 
4 x 9mm smooth idlers with 5mm bore

4 x M5 hex nuts

4 x M5x25 necessary, up to M5x40.  bolt head preferred but any will work.

Printing:

At least 2 perimeters

20% infill.  

0.2 mm layer height

ABS preferred, but should work fine in just about any material. 

Assembly:

insert screw from the outside and through a smooth idler.  Secure on the inside with a hex nut and tighten enough to secure the hexnut in the cavity.  Does not need to be super tight because you want the idler to move freely.