Spool saver - emergency solution for broken cardboard spools!

Did you drop your cardboard filament spool? Did it break?

Well, you have been naughty and now you are in trouble. Luckily, help is here! Meet the "Spool saver"! A 3D printable hub that will bring a cardboard/all-paper spool with a detached side back to life. If you know that you (or the kids!) are rough on your spools, print a few and install them directly when you take the spool out of the box! (There is also a “Spool stiffener” if you spool is too floppy, but not broken. See further down.) 

---- This is how you use the Spool Saver ----

Step 1. In the unlikely event of a spool breaking, carefully pick it up and make sure the filament doesn't fall off the centre core like a slinky. Leave it in a quiet place until you have printed the spool saver.

Step 2. Download the STL files for the Spool Saver (note the long "inside" version is for 1 kg spools, the short for 250-500 g spools). They share the same "outside" part.

Step 3. 3D print the spool saver. You need one "inside" and one "outside" part. No rafts or support needed.

Step 4: If one spool side has completely detached, place the spool with the detached side upwards. Gently lift the spool (making sure the filament doesn't slide off like a slinky) and insert half of the spool saver through the bottom.

Step 5: Gently adjust the filament, if needed, and place the detached spool side on top.

Step 6: Insert the other half of the spool saver and turn clockwise to thread the two halves together.

Step 7: You might have to gently "work" the spool and the filament to get the side to settle into place correctly while you are tightening the thread.

Step 8: Your spool is saved and you can get back to printing! :-D You might want to keep an eye on the spool to make sure the thread doesn't come loose over time.

Happy Printing! :-)

If your spool is completely ruined, like if you have dropped it in the bathtub, you might want to search for a “Masterspool” that replace the entire spool. 

--- Larger "Spool stiffener" - for spools that aren't broken (yet) ---

Cardboard spools are great for the planet, but aren't as rigid as plastic spools. If you have problems with the sides bowing out and the filament snagging - print a spool stiffener (LargeSpoolStiffenerInside.stl and LargeSpoolStiffenerOutside.stl) and add to the spool!

This reusable stiffener makes your cardboard spool as stiff as a plastic spool, but without filling up the planet with empty plastic spools.