Gear Train

How to play

Make the green wheel turn the way the arrow shows.

• Tap a gear in the tray, then tap an empty axle to fit it.
• Two gears mesh only when they touch: the size has to fill the gap.
• Each gear turns the opposite way of the one before it.
• Tap a fitted gear to take it back.

Tips

• Count the gears in the line: an odd number flips the end.
• Only one size fits each gap. Find it and the rest follows.
• There is more than one route. Pick the one with the right count.
• If two chains fight, the machine locks and nothing turns.