Contractible spool for filament coils

thingiverse

This text explains how to reuse filament coils without spools by using a contractible spool design that can easily be adjusted for insertion and auto-centering of the coil. The spool, created with only two parts (hubs and fork arms), is configurable in terms of the number of forks and dimensions. Each fork has three 3.2mm holes on each side, used to attach the inner and outer ends of the filament. The assembly uses M3x16mm screws and nylon nuts, with a center hole of 8.4mm, allowing it to be mounted onto an M8 threaded rod axis. STL files are provided for coil inner diameters ranging from 17cm to 23cm, and hubs for 3-6 fork arms. The SCAD file is fully configurable. Instructions for assembly include attaching the fork arms on a specific side of the wing and using screw nuts with built-in nylon stops. Post-print hole tightness can be adjusted with corresponding drill bits.