From the Loftsmith Workshop
Hand-crank Christmas pyramid for LED tea lights, 3 tiers
A Christmas pyramid you turn by hand instead of waiting on candle heat. Wind the little crank at the side and the three tiers spin, carrying trees, stars and snowflakes around. Round cups on the base hold LED tea lights, and you can change the cup size to fit yours.
26 parts · 203 g · 220 × 176 × 211 mm
Ask for the sizes you want to tweak, e.g. “make the width adjustable”.
How to print it
Parts
- base · PLA · Upright, flat bottom on the bed
175.7 x 175.9 x 47.9 mm, about 88 g, 123 min. Holds the four tea-light cups, the centre pin and the crank bearing block. Honey-wood colour.
- crown gear · PLA · Teeth up
40 teeth with an inner shroud ring, twisted column and hex spigot; about 19 g, 33 min. Honey-wood colour.
- pinion · PLA · Gear face down, sleeve up
20 teeth, D-shaped bore for the crank shaft; about 6 g, 16 min. Red.
- crank · PLA · On its flat side (the shaft flat is on the bed)
8 mm D shaft, arm and knob in one piece; about 5 g, 12 min. Red.
- tier 1 · PLA · Disc down
120 mm fluted disc with column; about 32 g, 51 min. Honey-wood colour.
- tier 2 · PLA · Disc down
94 mm disc; about 21 g, 37 min. Honey-wood colour.
- tier 3 · PLA · Disc down
68 mm top disc; about 11 g, 21 min. Honey-wood colour.
- riders 1 ×8 · PLA · Flat
Tree figures, about 1 g and 6 min each. Red.
- riders 2 ×6 · PLA · Flat
Star figures, about 1 g and 5 min each. Red.
- riders 3 ×4 · PLA · Flat
Snowflake figures, about 1 g and 5 min each. Red.
- finial · PLA · Upright
Twisted fluted spire with hex socket; about 2 g, 11 min. Red.
Print settings
- Layer height
- 0.2 mm
- Walls
- 2 (default); 3 walls if you want sturdier gears
- Infill
- 15%
- Supports
- None
- Notes
- All parts at 2 walls / 15% infill: about 209 g of PLA and 6 h 54 min in total (build estimate). At 3 walls / 15%: about 273 g and 8 h 40 min. The base is 176 mm across and fills a 180 mm bed on its own; the other parts go on a second plate. Two filament colours: honey wood for the base, crown gear a
Hardware
- 4 × LED tea light, about 38 x 16 mm (36-42 mm diameter via the slider) · Battery LED tea lights only, never real candles. Not included. No screws or other hardware needed.
Assembly
- Drop the crown gear onto the centre pin, teeth up. It hangs on the pin's tip and spins freely, 1 mm above the pedestal.
- Set the pinion on the crown gear teeth with its sleeve towards the crank block.
- Push the crank in from the outside through the block and into the pinion, matching the flat on the shaft to the flat in the bore. The pinion is now trapped between the block and the crown gear's inner ring.
- Push tier 1 onto the crown gear's hex spigot, then tier 2 onto tier 1 and tier 3 onto tier 2.
- Press the trees into tier 1, the stars into tier 2 and the snowflakes into tier 3 (tab down into each slot).
- Put the finial on top and drop the LED tea lights into the cups; use the notch in each cup to lift a light out to reach its switch.
- Turn the crank: two turns of the crank spin the pyramid once.
Good to know
- LED tea lights only, never real candles. PLA softens around 55 °C, and the cups would also fit a real tea light.
- The gear mesh and shaft clearances were checked as geometry in the Loftsmith engine at 145 sampled poses, not printed; continuous motion, loads and flex were not checked. If the gears feel tight, raise the Gear flank clearance slider.
- The riders are a friction fit (about 0.1 mm clearance per side) and their retention was not checked. If one is loose in its slot, a drop of glue is an optional fix.
- The teeth were checked against a 12 N push on the knob. If it jams, back the crank off instead of forcing it.
- The turning stack is held only by the centre pin (no top bearing), so a 3-tier pyramid can lean slightly. Keep it on a level surface.
- Small parts (riders, finial): not for young children.
- The base is 176 mm across; with the crank it needs about 220 mm of width.
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