Filament sub spools for sample packs

thingiverse

As I recently received 15 filament samples as a gift, I quickly realized how difficult it is to store them efficiently. On regular spools, they would take up too much space, winding and unwinding was annoying, and printing without a spool would cause problems. The following design solves this issue. In short, it consists of a replacement central cylinder for common filament brands ("filament-pm" and "prusament" spools), and a set of independent sub-spools that can easily be added or removed to the main spool. Thus, you can store filament samples on narrow sub-spools, then attaching them to a wide and stable main spool when needed. I designed two versions of the replacement cylinder: one to fit "filament-pm" spools (filament-pm is the company that delivers standard filament at the Prusa Store - these spool sides can easily be removed from the spool cylinder by pressing four locking tabs) and another for Prusament spools (just pull the sides loose from the paper coil). The "pm-spool" model has a convenient opening notch, making it easy to disassemble the spool. Unfortunately, for the Prusament spool, a tight fit is the only option as the sides do not have locking tabs. Each sub-spool will hold one filament sample (usually 50 grams). Such a sub-spool consists of two parts: a one-sided spool and a lock side to be attached after the sample has been inserted. The lock side is not necessarily needed, as several sub-spools next to each other form complete spools anyway. However, when using the sub-spools for storage between printing, you will need both sides. The spools are closed by pushing them together (there is a small inclination for the hooks). For opening, simply rotate the spool sides. The spool cylinder comes in two widths: 85.4mm which fits six sub-spools of 14.2mm each, and 57mm (or 42.8mm for Prusament) which fits four sub-spools (or three sub-spools for Prusament). You can easily create your own favorite combination by altering new widths in column B in the FreeCAD source file. A simple placeholder was added, as theoretically one placeholder plus five sub-spools will make six filament compartments within the "real" spool.