Gear Ratio Puzzle: Spin Right

Match the turn with real gears

Only for iPhone

Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.

iPhone

Place gears so the output turns the right way at the right speed. Meshing gears turn opposite ways and teeth set the speed: 120 puzzles with real gear rules. Place gears so the output turns exactly as asked. Connect the motor to the output axle and match goals like "clockwise ×2" or "counterclockwise ×1/2". The rules are those of real machines: • Meshing gears turn opposite ways • Speed changes by driver teeth ÷ driven teeth • Double gears on one axle multiply the ratio • A belt turns the other axle the same way at the same speed • A gear pushed two ways, or touching a brake, locks everything Solve with the fewest gears for three stars. Every one of the 120 puzzles is checked by a solver for a solution and its fewest gears. SIX CHAPTERS 1. Which Way? (free, 20 puzzles) 2. Faster, Slower 3. Double Gears 4. Belts 5. Brakes and Fixed Gears 6. Everything Together FULL VERSION (one-time in-app purchase) Chapter 1 is free. The full version adds 100 puzzles in chapters 2 to 6. No subscription, no ads. ACCESSIBLE • Hints show the next gear • Undo and clear • Playable with VoiceOver: every axle reads its gear and how it turns • With Reduce Motion on, arrows replace the spinning • Dark Mode and larger text PRIVACY No sign-in. Your progress stays on this iPhone and is never sent anywhere. No ads, no analytics. Works in Airplane Mode (only buying and restoring need the network).

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    Information

    Seller
    Norimitsu Ito
    Size
    1.1 MB
    Category
    Puzzle
    Compatibility
    Requires iOS 26.0 or later.
    • iPhone
      Requires iOS 26.0 or later.
    • Mac
      Requires macOS 26.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 26.0 or later.
    Languages
    English and Japanese
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    © 2026 Norimitsu Ito
  • Privacy Policy

    • Supports

    • Family Sharing

      Some in-app purchases and subscriptions may be shareable with your family group when Family Sharing is enabled. Learn More

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