You crank the story out of it: fast for cheerful, slow for spooky. Crank it backwards and the story rewinds and takes a different path.
Drag the crank around in a circle (with a mouse or a finger). Every third of a turn = one phrase. Fast = cheerful and golden, slow = dark and spooky. Once the fork chimes, try cranking backwards.
The demo uses the sentences from the concept. In the real toy, Claude writes the whole story tree in advance and every phrase exists in three pre-rendered tempos.
My 6-year-old daughter is cranking away, and out of the horn slides a strip of paper with a picture of a wolf. The wolf is about to knock on the door. She doesn’t like that one bit, so she cranks backwards. The narrator slows down: “Wait, wait… let’s go back to the path.” A little ↩ arrow prints on the paper, and under it: “…and the wolf changed his mind and went blueberry picking instead.”
The child slots in a “cylinder”: an NFC token that picks the genre, or casts a creature from the Hatchery (another toy idea) as the hero. A wish said out loud can go on top.
The tale is told in phrases of 2–5 words, and each one plays as the crank covers part of a turn. Stop cranking and the phrase finishes, then the narrator waits.
Fast: the quick, cheerful version and a major-key tune. Slow: the quiet, slow version in a minor key. The average tempo of one paragraph sets how cheerful or spooky the next one will be.
A chime announces a fork in the story. Cranking backwards after a fork rewinds the story to the last fork, and the narrator carries on down the second branch, already prepared.
The thermal printer prints a panel (a picture from the library + a sentence) only once the story has passed a fork, so the scroll records the path actually taken, rewinds included.
At the end you tear off the scroll with the map of your choices and color it in.
Every time you crank, it’s a different story, and the child steers it with their hands, not with buttons. Cranking slowly is a game of courage. Rewinds are exploration (“what would happen if…”). The scrolls get collected on the wall, each one a map of the child’s own choices. With creatures from the Hatchery, the hero is a character the child made up.
The story is generated ahead of time as a tree (a main branch plus an alternative at every fork), and the physical tempo of the cranking sets the mood of whatever text comes next.
Claude builds the pictures from a parent-approved library of outlines, so an unexpected picture can never appear.
Red, gold and cream, with ornaments. A horn as the sound box, a paper slot with a tear-off bar (PETG), a cylinder slot.
An AS5600 magnetic angle sensor reads the position smoothly, direction included, with no wear. The gearing is covered.
Embossed with the genre. Each cylinder carries a genre, or a creature from the Hatchery as the hero.
| Part | What for | Price (CZK) | Source |
|---|---|---|---|
| ESP32-S3-DEVKit | brain, plays phrases from PSRAM | 448 | platforms list |
| AS5600 magnetic angle sensor + magnet | smooth sensing of the crank and its direction, no wear | 60 | (estimate; not in the catalog) |
| (alternative) KY-040 | cheaper, but 20 clicks per turn | 29 | #33 |
| CSN-A2 thermal printer | the scroll | 928 | #67 (~Oct 23) |
| RC-522 + NTAG213 | cylinder | 67 | #30, #31 |
| INMP441 + button | wish out loud | 138 | #27 + (estimate) |
| MAX98357 + 40 mm speaker | voice + organ music | 187 | #48, #50 |
| 9 V/2 A power supply + step-down | printer + ESP | 180 | (estimate) |
| Total | without the KY-040 alternative · about €80 | ~2,010 |
Writes the story tree and picks the outlines.
Tracks the position in the story, picks the branch, maps tempo to a variant and enforces the spookiness cap.
Every cylinder keeps 3 pre-generated story trees (phrase MP3s + bitmaps) in flash. Without the microphone it still plays in full. Code enforces an age-based spookiness cap. BPA-free paper, covered gearing, and a printer with a covered print head.
First playable prototype: crank + phrases + one pre-generated tale, no printing.
Full version: story tree, rewinds, printed panels, mood from tempo.
Cranking backwards to rewind works as branching, with printing only after a fork (the paper records the path), and the sync stays realistic thanks to phrases pre-rendered in three tempos.
One of eighteen finalist toy ideas in the Toy Workshop, generated by AI agents, picked by a dad.
Made by Ondra Malacka with Claude agents · malacka.cz