The Tinkertoy Construction Set was created in 1914—one year after the A. C. Gilbert Company’s Erector Set—by Charles H. Pajeau and Robert Pettit in Evanston, Illinois. Pajeau, a stonemason, designed the toy after seeing children play with pencils and empty spools of thread. He and Pettit set out to market a toy that would allow and inspire children to use their imaginations.
The cornerstone of the set is a wooden spool roughly two inches (5 cm) in diameter with holes drilled every 45 degrees around the perimeter and one through the center. Unlike the center, the perimeter holes do not go all the way through. With the differing-length sticks, the set was intended to be based on the Pythagorean progressive right triangle.
The sets were introduced to the public through displays in and around Chicago which included model Ferris wheels. Tinkertoys have been used to create surprisingly complex machines, including Danny Hillis’s tic-tac-toe-playing computer (now in the collection of the Computer History Museum in Mountain View, California) and a robot at Cornell University in 1998.
Hasbro owns the Tinkertoy brand and currently produces both Tinkertoy Plastic and Tinkertoy Classic (wood) sets and parts.