Introduction: Clackers: the Toy of Doom

Things were so much interesting when toys were dangerous, right?

Wait, what?

Clackers were toys popular in the late 1960s and early 1970s. They are formed out of two hard plastic balls, each about 2 inches (5 cm) in diameter, attached to a tab with a sturdy string. The player holds the tab with the balls hanging below and through up-and-down hand motion makes the two balls swing apart and back together, making the clacking noise that gives the toy its name. With practice one can make the balls swing so that they knock together both above and below the hand (and honestly I was very good in knocking my hand as well... OUCH!).

Clackers were taken off the market in the United States in the 1970s when reports came out of children becoming injured while playing with them. Fairly heavy and fast-moving, and made of hard acrylic plastic, the balls would occasionally shatter upon striking each other: this resulted in shrapnel flying everywhere. There was anyway a comeback of a more "civilized" version in the 1980s with upgraded materials and geometry.

This is a (much safer) 3D printed version that will delight joyful parents with hours and hours of very loud clacking noise.


You will need:

  • 3D printer
  • STL files
  • glue

Step files are available here should you want to modify my geometry.

Step 1: Here We Go!

The version I designed introduce a geared mechanism with synchronized rotating arms: you can't go wrong! They will always strike each other exactly halfway as long as you take care of aligning the gears correctly when assembling the device.

Assembling the clackers is an easy task:

  • glue the handle on the plate
  • fit the gears with the arms laying parallel to each other and perpendicular to the imaginary line connecting the centers of rotation
  • glue the cover to the plate only (the arms needs to be free to rotate obviously)


Now grab the handle, shake the clackers up and down until the oscillations pick up the rhythm... and enjoy the music! :)

If you enjoy it why don't you vote for me in the contest?


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