Recent Blogs
Watt Six-bar Linkage: Mobility Count and Dwell-time Comparison
View a fixed illustrative Watt I six-bar. Calculate generic planar mobility and convert an entered interval to cycle angle and percentage at constant speed.
Ten-bar Linkage: Nominal Planar Mobility Calculator
Explore a conceptual ten-link chain and calculate its nominal planar mobility from link and revolute-joint counts. Dimensions and motion paths are not solved.
Sylvester–Kempe Linkage: Concept and Illustrative Budget
Explore the historical straight-line linkage concept and a separate illustrative mismatch-and-clearance budget. The arithmetic does not predict tracer error.
Six-bar Linkage Mechanism Explained: How It Works, Parts, Diagram and Uses
Explore a moving Watt-type six-bar linkage with seven pin joints and use the planar mobility calculator to compare link and joint counts.
Closed Four-Link Chain: Planar Mobility Calculator | FIRGELLI
Explore planar link and joint counts, the Gruebler–Kutzbach equation and a four-bar illustration. Understand connectivity and constraint assumptions.
Four-Bar Linkage: Grashof Margin and Geometry Explorer | FIRGELLI
Explore four-bar lengths, Grashof margin and sampled angles. Learn the limits of branch selection, angle spans and the illustrative index.
Eight-bar Linkage Mechanism Explained: How It Works, Parts, Diagram and Grübler DOF Formula
Explore a Jansen-type eight-bar walking leg with a calculated foot path. Adjust scale, crank radius and speed; see rigid links, joint count, travel and gait...
Double-rocker Mechanism: How It Works, Parts, Formula, Diagram and Uses in Four-Bar Linkages
Explore a double-rocker four-bar linkage. Set four link lengths to calculate assembly class, feasible input limits and sampled output swing.
Double-crank Mechanism Explained: How It Works, Diagram, Parts, Grashof Condition and Uses
Explore a double-crank four-bar linkage. Adjust link lengths, check the Grashof condition, and calculate instantaneous output speed through the cycle.
Cognate Linkage Mechanism: How It Works, Roberts-Chebyshev Theorem, Diagram and Uses Explained
Compare three Roberts–Chebyshev four-bar cognates tracing one point path. Scale the coupler triangle and inspect matching configurations and different fixed pivots.
Chebyshev Approximate Straight-Line Linkage: Exact Four-Bar Closure
Quadrangular rectilinear motion explained — how a four-bar linkage produces straight-line output, with formulas, tolerances, and real packaging-line examples.
Elliptical Crank: Trammel Animation and Point-Velocity Calculator
Explore a double-slider elliptical trammel. Adjust horizontal and vertical semi-axes, initial phase and cycle time while following position and speed.