Linkage Design

Program Linkages will design and analyze pin-jointed and slider linkages with four, five, and six links. All will synthesize and analyze the position, velocity, acceleration, dynamic force and torque of a linkage for one position, a full revolution of the input link at constant speed, the time response to a constant acceleration of the input link, or the response to a cam or servo-drive as input to the linkage. They will also generate and analyze the dynamics of the path of a coupler point on one or more links. The linkage is animated on screen and all calculated data are plotted or printed to screen or to an Excel-compatible disk file. The link on this page allow the download of a demo version that has all modules active.

There are seven modules in program Linkages. They may be purchased singly or in any combination, a la carte. Price information is in the How to Buy link at right.

All modules calculate kinematic and dynamic data for the particular linkage, plot, print, and export the results in Excel format as well as animate the linkage on screen. The modules are described below.


Fourbar synthesizes and analyzes any fourbar, pin-jointed linkage. Coupler curves are also drawn.

Fivebar synthesizes and analyzes any geared-fivebar linkage with any gear ratio and phase angle. Coupler curves are also drawn.

Sixbar synthesizes and analyzes any sixbar, pin-jointed linkage of the Watts II and Stephensons III inversions. Coupler curves are also drawn.

Slider synthesizes and analyzes any fourbar slider, pin-jointed linkage. Coupler curves are also drawn.

The Cam Driven Linkages module works with program DYNACAM to analyze the kinematics and dynamics of cam-driven fourbar and sixbar linkages with or without sliders.

The Engine module designs and analyzes internal combustion engines and air compressors for single cylinder to twelve-cylinder combinations in inline, vee and W configurations. Engine balance, shaking forces and torques along with all other dynamic data are computed

System Requirements

  • Windows NT/2000/XP/Vista/Windows 7/8
  • Pentium or better
  • 500 MB



  • Intuitive and user-friendly Windows interface.
  • Calculates Fourbar, Fivebar, Sixbar, and Crank-slider linkages.
  • Animation of the linkages and their coupler curve.
  • Cartesian plots of all calculated functions.
  • Polar plots of selected vector quantities.
  • Prints results to screen, printer, or a disk file.
  • Calculation of all dynamic force and torque data.
  • Provides information for sizing a flywheel.
  • Calculates needed balance masses to cancel shaking forces.
  • Calculates the Fourier transform of all parameters.
  • Synthesizes linkages for two- and three-positions of the coupler.
  • All results can be exported to a spreadsheet.