Hey Joel,

This design is meant to be somewhat modular. The file called shelf mount once printed should be able to snap onto the shelf. Then you can use either of the two holders with the mount. Both of my printers are down right now, so I can't print a test of my own. Also, I am not sure how to save the stl such that it opens in the slicer in the correct orientation. Good Luck finding a spool holder that works for you!

Kyle