Inspired by souvenir penny presses, [Robert] built the Olin College penny press. This machine stamps out coins with the school’s name and a variety of other patterns. He built it as part of a mechanical structures course, with the goal of designing something that used large forces.
Crushing a penny takes about five tons of force. To deliver that force, [Robert] used a 1 horsepower motor coupled to a custom 1190:1 reduction drive train, which consisted of sprockets, gears, and chains. The aluminium frame supporting the drive train also had to be designed to withstand large forces.
This required of a lot of custom parts, which were made using a CNC mill, a water jet cutter and a mill. All of the CAD drawings are available for anyone who wants to replicate the design.
This beast of a machine weighs about 90 pounds and can squish 12 pennies every minute. Olin College installed the penny press on their campus for anyone to use for free.