The Hourglass Filler

Design the interior vessel shape and calibrate sand flow to measure exactly one minute. Fight against granular jamming and arching physics!

JAM DETECTED!
0.00
Target: 60.00 seconds

Actions

Design Mode

Neck Shape

Sand Properties

Presets

Stats

Grains: 0
Flow Rate: 0/s
Jams: 0
FPS: 0

How to Play

  • Goal: Design an hourglass that takes exactly 60 seconds to empty
  • Flip the hourglass to start the timer and sand flow
  • Adjust neck width to control flow rate - narrower = slower but more jams
  • Adjust neck length to affect jamming probability
  • Shake to break jams when sand gets stuck (costs accuracy!)
  • Click and drag in Widen/Narrow modes to sculpt the vessel shape
  • Watch for arching - grains forming bridges that stop flow
  • Smaller grains flow better but larger grains look more satisfying

Physics: Granular jamming occurs when particles form stable arches at constrictions. The critical arch width is approximately 4-5 grain diameters.