(This Thing is a Work-In-Progress because i didn't test-printed it yet.)

This is a remix of RichRap's MasterSpool (https://www.thingiverse.com/thing:2769823). I give him the credits for this system.

I optimized a few things on it:

• outer diameter: 195mm (optimized for 200x200mm beds)
• holes to fix the end of the filament to the side of the spool
• holes to screw the spool together, so it can't screw itself loose. (M6 bolts and nuts needed)
• added level indicator

Additionally you will need 3x M6 nuts and 3x M6x45 cylinder head bolts

Except for the outer diameter (195mm), the dimensions are the same as RichRap's spool.

You need to print both parts, that the holes fit together.

I added the Fusion360-files, so you can edit it.

v2 changelog:

• added 3 level indicators, so it looks symmetrical.
• increased the diameter to 198mm.
• added slots for the inner end of the filament.
• modified the coupling system, so it can be one STL-file (thanks to @pew in the comments for the idea).