Galilean Dead-Drop Gravity Escapement Clock
A challenging, hands-on discovery and STEM project designed for curious young minds aged 10 to 14.
Materials Needed
- • High-density corrugated craft cardboard (2 sheets (A4 size))
- • Wooden barbecue skewers (blunted) (2 units)
- • Plastic drinking straw (for bushings) (1 unit)
- • Sewing thread (1 meter)
- • Heavy steel washers or metal nuts (6 units)
- • Hot glue gun and craft knife (adult supervision) (1 set)
Pro Tips
- → Precision is key: cut the ratchet escape wheel teeth at uniform 30-degree angles to avoid tooth jamming.
- → Adjust the suspended pendulum length to test Galileo’s law: a pendulum of identical length swings with the same period regardless of swing amplitude.
- → Add or remove washers on the drive-weight string to find the minimum torque needed to keep the wheel stepping.
Safety First
Adult supervision required when using hobby utility knives and hot glue guns.
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Step-by-Step Instructions
Step 1
Draft and cut a 12-tooth ratchet escape wheel (10 cm diameter) and a curved twin-pallet anchor from rigid cardboard.
Step 2
Mount the wheel onto a smooth wooden skewer axle set into a vertical cardboard backplate using low-friction drinking-straw bushings.
Step 3
Pivot the anchor pallet directly above the wheel on a pin, counterweighted by a 25 cm hanging pendulum arm with washers at the base.
Step 4
Wind a thread carrying three heavy washers around the main axle, release the anchor, and adjust pallet angles until steady, continuous ticking occurs.