Four-Bar Linkage Simulator
Interactive simulation tool for four-bar linkage mechanisms. Adjust link lengths, check Grashof condition, trace coupler curves, and analyze angular positions, velocities, and transmission angles.
Preset Configurations
Mechanism Parameters
Animation Controls
Quick Actions
Generate complete kinematic analysis across full 360° rotation for all experiments.
Experimental Analysis
Coupler Results
Follower Results
Transmission Angle Results
Mechanical Advantage Results
Joint B Velocity Results
Coupler Curve
X-Y path of the coupler midpoint through one full input rotation. The shape of this curve determines what complex motion the mechanism can generate.
Download Professional Resources
Get experimental data generated for your specific parameters, along with professional engineering resources
All data generated for your exact mechanism parameters. 1 USD per item, or buy all as a package.
What You Can Adjust and Explore
This free, browser-based four-bar linkage simulator lets you change every parameter below and watch the animation, the coupler curve, and the angle, velocity, and transmission-angle charts update in real time.
Adjustable parameters
- Input crank a: 10 to 120 mm
- Coupler b, follower c, ground d: 20 to 200 mm each
- Ground offset e: -50 to 50 mm
- Crank speed: 10 to 120 RPM, with manual crank-angle control
- Assembly: open or crossed circuit
One-click presets
Crank-rocker, double-crank, double-rocker, triple-rocker, and parallelogram load classic four-bar types, with an automatic Grashof classification.
What it computes
Coupler and follower angles and angular velocities, transmission angle, mechanical advantage, joint velocity, and the coupler curve, plotted against crank angle or time, with two-configuration A/B comparison and downloadable data.
Frequently asked questions
What can I adjust in this four-bar linkage simulator?
The four link lengths (input crank 10 to 120 mm; coupler, follower, and ground 20 to 200 mm each), a ground offset (-50 to 50 mm), the crank speed (10 to 120 RPM), the open or crossed assembly, and five one-click presets: crank-rocker, double-crank, double-rocker, triple-rocker, and parallelogram.
What does the simulator compute?
Coupler and follower angles and angular velocities over a full crank rotation, the transmission angle, mechanical advantage, joint velocity, and the coupler curve traced by a point on the coupler, plus an automatic Grashof classification.
What is the coupler curve?
The path traced by a point on the coupler link through one full input rotation. Its shape determines the complex motion the linkage can generate, and the simulator draws it live.
Is it free, and does it work on mobile?
Yes. It is free and runs in any modern web browser on desktop, tablet, or phone with no installation, with downloadable data and engineering resources.