Galton board bean machine

thingiverse

The normal distribution device, also known as the binomial demonstration or probability simulator, is a contraption devised by Francis Galton to prove the central limit theorem, particularly that the binomial distribution closely resembles the normal distribution. The device comprises a vertical board featuring intricately arranged rows of pins that are offset at regular intervals. Small balls are released from above and then ricochet back and forth with each bounce against the pins below. Eventually, the balls settle into corresponding receptacles at the bottom of the apparatus, which are specifically designed to accommodate a single row of balls. The precise configuration used in this particular prototype consists of soy beans dropped down through the machine. The variables defining the machine can be modified using an OpenSCAD file, allowing users to adapt the design for various other objects they wish to experiment with. Using a high-precision Ultimaker 2 printer, each component was individually printed and then securely assembled together using a durable adhesive substance.