Milwaukee Muscle

This exhibit is about movement, power, and you. Explore force, hydraulics, motors, gears, and power. Investigate ingenious engineering, and learn how machines move!


Explore and understand the science of hydraulics at these fun, interactive stations.

A Real, Working Mini-Excavator! – The main exhibit in the Fluid Power area is a real, working excavator. Able to lift thousands of pounds, this hydraulic mini-excavator is easily as powerful as the old cable and gear steam shovels that were used to dig the Panama Canal. Here at Discovery World, visitors work together to operate the boom, bucket, swing arm, and tracks.

Visitors will also explore three concepts that are central to the science of hydraulics.

  • Pascal’s Law: How does hydraulics work? At this station, visitors will investigate Pascal’s Law, which is the foundation of hydraulics and one of the principles of fluid mechanics. Visitors will use a piston and hydraulic fluid to multiply force and lift an impressively large object.
  • Power Density: How powerful is fluid power? In the case of hydraulics, a little volume means a whole lot of power. At this station, visitors will step onto a platform, and a friend or family member will give them all a lift using nothing more than hydraulic fluid and a small, hydraulic pump.
  • Flexible Power: Why use hydraulics? What makes fluid power so flexible? At this station, visitors will compare a hydraulic circuit with a mechanical circuit made of sprockets, chain drives, and gears. This engaging side by side comparison highlights the versatility and simplicity of a hydraulic system.

These incredibly fun and interactive exhibits demonstrate the amazing power and precision control of hydraulics.


  • Gears and Pulleys: Simple devices that make labor-intensive work easier. Explore worm gears, spur gears, and bevel gears to see how they help you do the heavy lifting. See how pulleys function similar to gears, but with belts rather than teeth.
  • Automatons: More than a dozen of these elegant machines feature sophisticated mechanical parts such as gears, pulleys, cams, and cranks. They are precursors to robots and excellent examples of how complex machines work.
  • Engines: The internal combustion engine is the most common engine in modern transportation. View engines and their components, including a transmission and clutch.
  • Southwest Airlines Flight Simulator: Take flight without ever leaving the ground! Pneumatic muscles that move you in six directions giving you the same experience as a beginning pilot.
  • Bernoulli Table: Investigate the foundations of fluid dynamics at this amazingly fun table. Suspend colorful spheres in the air as you discover how flight works.
  • Helicopter: Climb in the cockpit and take the controls. See how cyclic stick and anti-torque pedals move the rotors!