01 / RIB
The long member supports the canopy. Its angle changes as the runner drives the support linkage.
An interactive study of everyday engineering
Every fold
has a logic.
One umbrella. A hidden system of connections. Move the runner, follow the ghost, and bring the mechanism back to life.
● THE EVERYDAY ENGINEERING COLLECTION
01OBSERVE02INVESTIGATE03RESTORE
ENTER THE FOLDING LAB →5 mechanical cases · Free · No sign-up
Your mission: find the fold that breaks the pattern.
01 OBSERVE02 INSPECT03 RESTORE04 VERIFY
CASE 02 / STRUCTURAL VIEW● LIVE MODEL
ROTATE THE OBSERVATION
CONNECTEDGHOST PATHSELECTED
EDUCATIONAL KINEMATIC MODEL · FABRIC IS A VISUAL APPROXIMATION0 / 5 CASES RESTORED
01 / THE CASE ARCHIVE
Small faults. Beautiful discoveries.
Each case explores a different failure in the same simplified linkage. No timer. Your best tool is curiosity.
02 / ANATOMY OF A FOLD
A little machine.
An elegant chain reaction.
The runner does not pull eight ribs independently. It changes the geometry of a connected system.
02 / STRETCHER
A fixed-length support connects the runner to a point on the rib. These three points form a changing triangle.
03 / RUNNER & SHAFT
The runner slides along the shaft. In this model the rib attachment and support lengths stay constant while runner height changes.
03 / EXPERIMENTAL STUDIO
Break the pattern. Find the order.
Create a solvable fault or explore the visual order of canopy pleats. Experiments happen only in this browser.
FAULT INJECTION / MAKE A FAILURE
Design the next mystery.
Every generated case has one fault and a matching restoration action. Share a link directly; no community server is used.
CANOPY ORIGAMI / VISUAL EXPERIMENT
Give the fabric a rhythm.
Tap each pleat to set its wrapping direction. Match all six directions for a consistent wrap.
3 / 6
Pleat alignment score — not a physical volume measurement.
04 / THE SCIENCE OF FOLDING
Understand what the motion reveals.
Why does an umbrella fold?
The upper hub anchors the ribs to the shaft. As the runner moves down, each stretcher pulls its rib toward the shaft. The support cannot change length, so its endpoints must follow the geometry of the linkage. Moving the runner changes every connected rib at once.
Our lab calculates this triangle with a fixed rib attachment distance and support length. The ghost shows the fault-free geometry at the same runner position. It is a constrained educational model, not a product-specific engineering analysis.
Why won’t an umbrella close?
A misaligned rib, fabric caught near a joint, or a runner latch that has not released can all interrupt movement. A visual comparison can suggest where to look, but different mechanisms can produce similar symptoms. Select the corresponding virtual case to see the role of each component.
If a real umbrella resists, stop applying force. Keep fingers clear of joints. Follow the manufacturer’s instructions; do not dismantle spring-loaded automatic mechanisms. This tool cannot diagnose your umbrella.
What changes in a folding umbrella?
Compact umbrellas add rib segments and sometimes a telescoping shaft. Extra joints coordinate a shorter packed shape, but their exact linkage differs by manufacturer and model. A reverse-folding umbrella also changes how the canopy is arranged during closure.
The five cases here use one conventional linkage so cause and effect remain clear. The fabric experiment tracks direction consistency only; it does not model wet cloth, friction, packing volume, or material strength.
Field notes & questions
How do I solve a case?
Move the opening slider, compare a rib with its blue ghost, select the affected rib, and apply the matching action. Then verify. Case 01 asks you to fully close and fully open the umbrella.
Does Ghost Fold reveal the answer?
It overlays the normal geometry for the current runner height. A mismatch is evidence, but you still need to inspect the part and choose a restoration action.
Can I use the lab with a keyboard?
Yes. Tab through the controls and ribs; use Enter or Space to inspect a rib. Use arrow keys on the slider, or the Close and Open buttons.
Where is my progress stored?
Completed cases are stored locally in this browser when storage is available. Clearing browser data removes that progress. Puzzle links contain only a fault type and rib number.
Is there a daily challenge?
Use the daily button below for a date-based case. It uses your device’s local date and is replayable; it is not a competition leaderboard.
DAILY FOLD MYSTERY
A fresh observation, every day.
One date. One reproducible fault. Follow the motion and restore the connection.