From the Loftsmith Workshop
Filament spool cord reel hub with crank, 50-58 mm bores
Turns an empty filament spool into a hand-cranked cord reel. The crank handle spins the spool, so extension cords and long cables wind up neatly instead of ending in a tangle. Set it to your spool's bore and the width between its flanges.
4 parts · 92 g · 122 × 73 × 225 mm
Ask for the sizes you want to tweak, e.g. “make the width adjustable”.
How to print it
Parts
- hub · PETG · Crank paddle flat on the bed with the sleeve standing up. It prints as one object with grip-axle inside it.
About 48 g and 72 min at 2 walls/15%. 121.5 x 73 x 79.1 mm at the defaults. Sleeve with six snap fingers, a 6 mm crank paddle, an 8 mm drive peg on the paddle's spool-side face, and a 45-degree bushing web. No supports (0.0% overhang).
- grip-axle · PETG · Printed in place inside the hub, standing on its bearing wheel. It is 177.6 mm tall at the defaults.
About 32 g and 63 min. Fluted 30–32 mm grip with a rounded end knob. It turns in a captive V bearing at the paddle and a bushing ring higher up. Free it with a firm twist after printing.
- knob-pin · PETG · Head down on the bed, printed inside the knob (one object with knob).
About 4 g and 15 min. A 13 mm pin with a four-prong snap shank that clicks into the crank arm.
- knob · PETG · Printed around knob-pin, standing on the bed.
About 8 g and 18 min. Fluted 25 mm knob, 44 mm long, that spins on the pin.
Print settings
- Layer height
- 0.2 mm
- Walls
- 2 (page default); 3 if you want a stiffer grip
- Infill
- 15% (page default)
- Supports
- None
- Notes
- PETG, chosen for the snap fingers and to cope with a warm garage or car. At 2 walls/15% everything is about 95 g and about 2 h 53 min: the hub print with the grip inside is about 80 g and 2 h 15 min, and the knob print about 12 g and 33 min. At 3 walls/15% it is about 125 g and 3 h 46 min. The grip
Hardware
- 10 mm drill bit (tool, only if needed) · Only needed if the spool side has no window where the drive peg lands. The peg centre sits 12 mm out from the bore edge. No screws, nuts or glue are used.
Assembly
- Print the hub (crank paddle down, grip inside) and the knob (head down). Neither needs supports.
- Hold the paddle and twist the orange grip firmly until it turns freely. Do the same with the knob on its pin.
- From the flat outer side of the paddle, push the knob pin's snap shank into the hole at the end of the crank arm until the barb clicks into the recess on the other side.
- Find where the 8 mm drive peg will sit on the spool side: 12 mm out from the bore edge. If there is no window or hole there, drill one 10 mm hole at that spot.
- Push the hub through the bore from the peg side, grip first, so the peg drops into its hole. Press until the six fingers click over the far edge of the bore (roughly a 6 kg push).
- Wind: hold the grip in one hand and turn the knob with the other. Trap the cord end under the first few turns.
- To take it off, squeeze the six finger tips inward on the far side and push the hub back out.
Good to know
- The crank turns the spool through the drive peg. You need a window in the spool side at the peg, or one 10 mm hole drilled there. Without it the hub just spins in the bore.
- Set the bore and width sliders to your measured spool. The fingers catch about 1 mm past the far bore edge, so a spool more than about 1 mm wider than the slider will not latch.
- The capacity figure (about 19 m of 8 mm cord at the defaults) is a geometry estimate with a 0.75 packing factor. It assumes a 200 mm rim and the core diameter you enter, so measure your spool's core.
- Strength checks assume a 2 kg reel of spool and cord, and a 30 N pull on the knob, both doubled for jolts. Do not use it for heavier loads or to pull or hang anything.
- Fully unwind an extension cord before running a heavy load through it, and follow the cord maker's advice. This hub does not touch any wiring.
- There is no cord-end clip. Start winding by trapping the plug end under the first turns.
- PETG print-in-place parts can fuse. If the grip or knob will not free up, reprint with Running clearance at 0.4 mm.
- At the defaults the hub print is 177.6 mm tall. For spools wider than 69 mm it grows past 180 mm and needs a printer taller than an A1 mini.
- This was checked in the Loftsmith engine only. It has not been printed or tested on a real spool, so the snap feel, the push-in force and how freely the parts turn are estimates.
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