Recent Blogs
Watt Straight-Line Linkage: Animation and Path Calculator | FIRGELLI
Explore a Watt four-bar, vary link lengths and input sweep, and compare approximate straight-line travel with the actual sampled lateral deviation.
Watt Parallel Motion: Linkage Illustration and Coupler Division
Explore a fixed illustrative Watt four-bar and calculate an inverse-length coupler division. Entered dimensions do not define a complete custom linkage.
Chebyshev Plantigrade Machine: How This Walking Linkage Works, Parts, Formula, and Uses Explained
Explore four Chebyshev linkages driving two alternating foot frames. Calculate foot sweep, lift and the small height variation along the approximately level stance path.
Wittgenstein's Rod: Clearance and RSS Error-budget Calculator
Compare entered rod clearance, pin play and straightness with an assumed root-sum-square budget. The tool does not solve linkage motion or production tolerances.
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.
Quadruplanar Inversor: Ideal Circle-Inversion Map
Quadruplanar Inversor explained — how this 4-bar inversion linkage converts circular motion to straight-line travel for drafting tools, optics jigs, and lab gear.
Peaucellier-Lipkin Linkage: Exact Straight-Line Inversor
Explore the Peaucellier-Lipkin straight-line linkage. Calculate the inversion constant, line offset and ideal output stroke from link lengths and driver swing.
Hoecken Linkage: Link-Length Scaling and Model Limits | FIRGELLI
Explore approximate straight-line linkage geometry and calculate scaled link lengths. Velocity variation, usable stroke, full-cycle closure and payload are not verified by this tool.
Evans Grasshopper Linkage: Coupler-Path Calculator | FIRGELLI
Explore an Evans four-bar linkage with an approximately straight coupler path. Compare link scale, crank sweep, traced stroke and lateral wander.
Cardan Straight-line Mechanism: How It Works, Diagram, Formula, and Uses Explained
Explore the Cardan straight-line mechanism: a half-size pinion inside a fixed ring. Compare pitch diameters, stroke and tooth counts in the ideal 2:1 geometry.
Hart's A-frame: Straight-Line Linkage and Interactive Animation
Explore Hart's A-frame with connected rigid links and a straight tracing path. Compare bar dimensions and distinguish ideal geometry from build accuracy.