An easy to use tool to move filament between two spools. Don't waste a kilo of your filament on something you'll probably never use. No extra parts needed to complete the print, just hook it up to a drill and have something to hold your bad spool like your external spool adapter on your machine and just crank away, don't go too fast. I use reverse and just move the tool left and right to make the filament go back and forth.

Printing instructions: If you use the stls make sure it prints the top drill bit attachment part solid. I added extra walls to the bit attachment part by adding a small negative cylinder. As you can see it creates a core structure for extra stability without the need for a bunch of extra walls and filament. Model comes in just under 80g with my recommended settings.