FOUR BAR CHAIN

Using the four bar chain model, rotary motion is converted into oscillatory motion. A sturdy bench top base, with mounting feet and carry handles, incorporates a disc mounted on ball bearings as a crank. The disc has a protractor scale so that the rotational angle can be accurately viewed and measured. The crank pin connecting the crank to the disc can be set at different radii on the disc. The connecting rod and the oscillating lever are connected together in different lengths using quick-fit bolts. The oscillating crank is attached to a disc with its own protractor angle scale.

By rotating the crank and crank lever, the connecting rod is free to move vertically in an oscillatory motion.