I was looking for an easy solution to have several spools in front of my printer in a pretty cramped bookshelf so I cam up with this.

The uploaded STL files are designed for an IKEA Billy bookshelf with a shelf thickness of 19.2 mm and a standard 1kg spool (ext dia. 200mm, hole dia 50 mm, width 60mm).

I included the Fusion 360 file in the (most likely) case you need to adjust the model to your shelf and/or spool.

IMPORTANT : The model is parametric ! You can change all needed parameters under "Modify" -> "Change Parameters" and the model will automatically adapt to your input. The basic parameters you need are all marked as Favorites. Feel free to tweek the other parameters if needed but I recommend you keep an eye on the model while you do so in order to understand what they do. You are of cause free to change the dimensions directly in the Sketches but beware that you might break some constrains and links and end up with a weird/broken model ;)

Just print the two pieces separately without supports (no angles above 30° in this model unless you touch some advanced parameters) and you are good to go.

This is my first big project on Thingiverse so you are very welcome to like, comment, post makes and remixes or contact me if you have any questions :)

Many thanks in advance.

PS : Fusion 360 is free for Hobbyists, Students and Educators (https://www.autodesk.com/campaigns/fusion-360-for-hobbyists and https://www.autodesk.com/products/fusion-360/students-teachers-educators)
PPS: I included the STEP file as well in case someone needs it.