How robots work · about 5 minutes

Why big turns small.

crank worm 12-tooth gear LOCKED

Step 1: Turn the crank once. Watch the blue dot on the gear.

Crank turns: 0 · Gear: 0 of 12 teeth
  1. 1 · One turnOne crank turn moves the gear one tooth.
  2. 2 · All the teethKeep going until the dot is back on top.
  3. 3 · Push backTry to turn the gear by itself.
Build check

Building one with real bricks.

Follow your kit's instructions. When your worm gear model is built, check these four things.

  1. The worm and the crank share one axle. When you turn the handle, the worm spins with it.
  2. The two axles cross at a right angle. The gear's axle goes through the frame. The worm's axle runs across, under the gear.
  3. The teeth sit in the worm's groove. If the gear wobbles or skips, it is too far from the worm. Move it one hole closer.
  4. Test it. Count the crank turns for one full gear turn. It should match the number of teeth on your gear. Then twist the gear by hand. It must not move.
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