J. Mike Rollins (Sparky) [rollins@wfu.edu]
Hyperbola New
My Cats New
Kitty New
Mike is on
Green Cycle Design Group
  My Stuff  
  My Truck  
Jacob's Ladder
My House
My Cars
My Cats New
My Jokes
Pi Poetry
Toro Mower
Speed of a Piston
   Offset Crankshaft
Not a Pipe


Here are some additional resources:

Graphing Demonstration of the Motion of a Piston

    Enter values for Rod Length, Crank Radius and RPM and select Restart to demonstrate the behaviour of the piston.

    Select the attribute to be displayed in the graph by selecting the Graph Mode.

    Click on the Meters Bars to display the real-time values and a graph for the respective attribute.

    The default values for this example are 3.5 inches for the radius of the crank and 5.5 inches for the length of the rod. Thes are not good values for a real engine, however they do produce an interesting value for acceleration.

  • You can modify the values for Rod Length, Crank Radius and RPM. Press Restart after changing these new values will take effect. The value for RPM will not change the speed at which the animation is displayed, but will be used to compute the values shown at the bottom.
  • You can Click on the Meters for Location, Velocity and Acceleration. Clicking on these will display the value in real-time at the bottom and will be graph at the top.
  • Disclaimer: The values shown are based on the equations I derived at The Speed of a Piston. I do not guarantee any of my work here.
  • The graphs are created by the the JCCKit library.

The location is given by s(t), the velocity is v(t) and the acceleration is a(t). The equation for these functions are given in the following figure. The crank shaft radius is denoted as r and the connecting rod length is b.