This is one of a set of three clock models that show how the necessary 60-to-1 gear ratio between the second and minute hands in a mechanical clock can be achieved in a practical way. This model shows how it’s done in three stages: first 7 teeth to 21 teeth gives 3-to-1 reduction, then 7 teeth to 28 teeth gives a 4-to-1 reduction, and finally 8 teeth to 40 teeth gives a 5-to-1 reduction. 3 times 4 times 5 gives 60-to-1.

Our Two-Stage Clock Gear Chain model shows how the same can be done in two steps, which uses fewer gears, but is actually larger overall. (Doing it in one stage, with a 6-tooth and a 360-tooth gear, is theoretically possible, but crazy big, so we offer it only on special order.)

Finally, our Electric Clock model uses the three-stage design, and adds a further gear chain for the hour hand, and a battery-powered watch movement to drive the second hand, resulting in a full working clock. More practical, but not as much fun to use like a fidget spinner!

Our Complete Clock Set includes all four models for a discounted total price.

Your model will arrive attractively packaged with all the necessary parts and tools. It does not require any special model-building skills. A detailed, step-by-step assembly video is available on our instructions page.