Recent Blogs
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.
Whitworth Quick Return: Ideal Crank-angle Timing Calculator
Compare ideal cut and return times from a constant-speed crank-angle model. The calculator does not solve the complete Whitworth linkage or its stroke.
Geared Continuous Hinge: Door-Weight Moment Calculator | FIRGELLI
Compare static door-weight moment and average moment per inch of hinge length. Learn how geared leaves, cap and bearings work and where product ratings are...
Burmester Theory: Four-bar Body Guidance and Pivot-Offset Calculator
Explore Burmester body-guidance principles and a four-bar example. Compare coupler-point displacement at four input angles after a fixed-pivot offset.
Equalizing Lever: Load Sharing, Rocker Animation and Calculator
Compare ideal load shares in an equalizing lever. Enter the two arm lengths and see how a rigid rocker divides a vertical frame load between...
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.
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.
Watt's Linkage: Illustrated Path and Cubic Comparison
View the midpoint path of a fixed illustrative Watt four-bar. Compare an assumed cubic expression with an entered allowance; it is separate from the drawn...
Twelve-bar Linkage: Planar Mobility Count Calculator
Calculate the planar lower-pair mobility count from link and joint totals. Connection geometry and constraint independence must be checked separately for a real linkage.
Tusi Couple: Two-to-one Geometry and Straight-line Stroke
Explore the ideal straight-line trace of a circle rolling inside a circle twice its diameter. Calculate stroke and amplitude for the exact two-to-one case.
Three-link Kinematic Chain: Generic Planar Mobility
Compare open and closed ideal three-link chains, counting ground as one link. Calculate nominal mobility and joint constraints without solving dimensions or motion.
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.
Swashplate Mechanism: How a Helicopter Rotor Head Works, Parts, Diagram and Uses Explained
See how collective and cyclic controls affect a helicopter swashplate. Explore ideal attachment height and frequency; blade pitch and loads are not calculated.
Studded Disk and Bell Crank: Alternating Motion Calculator | FIRGELLI
Explore a studded disk driving a bell crank with a weighted-cord return. Calculate event timing, ideal cord tension and counterweight moment.
Hoeken Straight-Line Example: Animation and Path Calculator | FIRGELLI
Scale a defined Hoeken four-bar and compare travel, sampled deviation and crank period. See the approximately straight working interval and curved return.
Stephenson Topology Six-bar Linkage: How It Works, Diagram, Parts, Uses & Calculator
Stephenson topology six-bar linkage explained — how it works, kinematic equations, and real applications in packaging, automotive seats, and industrial machines.
Steering Linkage Mechanism Explained: Ackermann Geometry, Parts, Diagram and Calculator
How a Steering Linkage works, with Ackermann geometry, tie rod sizing, bump steer math, and a worked example for an off-road truck build. Engineer's guide.
Slider Crank Chain Inversion Mechanism: How It Works, Diagram, Parts and Uses Explained
Explore a crank-driven slotted lever and connected ram, and compare ideal long and short stroke times from crank radius, pivot spacing and speed.
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.
Single Pivoted Clamp with Fixed Side-piece: How the Lever Mechanism Works, Parts & Uses
Explore a curved pivoted clamp jaw and fixed side piece, then compare ideal lever forces with selected arm lengths and a loss percentage.
See-saw Mechanism Explained: How a First-Class Lever Balances Torque, Parts, and Uses
How a see-saw lever works, the pivot geometry that makes it balance, and real-world examples from playgrounds to industrial counterweighted lifts.
Screw-clamp (handle and Lever Holder) Mechanism Explained: How It Works, Parts, Formula and Uses
How a screw-clamp handle and lever holder works, the clamping force formula, and real-world examples from machine shops, jig builders, and fixture designers.
Scott Russell Linkage Mechanism Explained: Diagram, Formula, Stroke and Uses
Scott Russell linkage explained — how this straight-line mechanism converts rotary motion into perfectly linear travel for test rigs, lifts, and lab equipment.
Rod End Bearing Mechanism: How It Works, Parts, Diagram, and Linkage Uses Explained
Rod End Bearings (Heim joints) handle misalignment in linkages — see how they work, load ratings, failure modes, and selection rules for motorsport and CNC...