3D printer accessories

Filament arrives on the wrong reel. Tangles want rewinding under tension, 2 kg rolls want halving before they will sit in a dry box, and an orphaned end deserves a smaller spool rather than the bin.

Crank it. Pick gearing anywhere from 1:1 to 2:1 — quick and firm, or slow and kind to your wrist — and the handle relocates to suit. The spindle lifts out of an open channel, so swapping reels takes seconds.

A reel that drags costs you something on every layer. Rather than resting on a bar, the spool is gripped between two threaded cones that pull it true on its own hub — a 250 g sample or a wide 2 kg reel, any boss from Ø41 to Ø66.

The shaft drops into open slots and gives line the moment it is asked. It stands level with our Filament Winder and shares the very same printed cone.

The spool sits between two threaded cones on a spindle carried at both ends, so it runs true instead of wobbling off a stub axle. The crank drives it through a printed gear train whose ratio you pick when you order — 1:1 when you want feel, up to 2:1 when there is a lot of filament to move.

The spindle lifts straight out of its open slots, loaded, so changing what you are winding onto is a lift rather than a strip-down. What you wind, and what you wind it from, is yours to arrange: the machine turns a spool steadily, in front of you, and stays out of the way of the rest.

One thing worth knowing before you print it: this is a light machine, and a full spool carries real inertia. Stand it on something grippy, or keep a hand on the frame while you crank.

Cardboard sags, cracks, and sheds dust into your feed path; refills and sample coils arrive with no spool at all. Print a rigid one instead — wind onto the hub, screw the two halves shut over the coil, and it drops onto any holder you own.

A single 55 mm bore serves all three sizes, so a 250 g sample and a 2 kg reel run on the same rod. Both halves print flange-down, unsupported. Free.