This cable spool was made specifically to fit the ChatMix dial on top of the spool while allowing the cable attached to the dial wind up inside the spool.

The top of the spool involves a fitted snapping function for assembly that is made of two pillars that have to bend in order to function properly. I recommend printing the top part of the spool on its side as that will add more strength to the pillars than printing it flat on its top.

The ChatMix dial itself can easily fit into the oval recess in the top of the spool and can be easily secured in place with a little sticky tack or other removable adhesive. 

Once printed simply feed the ChatMix dials USB cable through the groove in the top of the spool and then in-between the two pillars. Next thread the cable through the circular hole in the bottom half of the spool and push it to the side through the adjacent slit. finally simply push the end of the two pillars into the circular hole locking the two pieces together.