** 07-16-2018 Update: add a larger slot key so it's easier to handle and not as easily lost.
I designed this for the 3DPN Design Challange. It is very simple, yet still a modular system that works with 1x4 framing, or can be adapted with simple bracket changes.
You can choose from a protruding bracket design, or a bracket that keeps the spool parallel to you 1x4 framing. The bracket and arm attach to each other with a common drywall screw.
The arm is slotted towards the end every 10mm, so you can use the "key" slipped into it to keep slimmer spools from sliding around.
If the sizing of your wood it not precise, there is a threaded 1/4-20 hole on the back that can be used with a wing-bolt to lock the bracket onto the 1x4.
Lastly, there is an addon for using in a reverse-bowden setup. The bowden guide attaches between the bracket and the arm as you run the drwall screw in. The guide is threaded for an M10 bowden connector.