Recent Blogs
Trotbot Leg Linkage
Trotbot leg linkage explained — geometry, foot path, formulas, and a worked walking-robot example. Build notes from FIRGELLI's chief engineer.
Ghassaei Walking Linkage
How the Ghassaei walking linkage works — a single-DOF leg mechanism for kinetic sculpture, robotics demos, and educational walkers. Diagram, formula, examples.
Sarrus Linkage
Sarrus Linkage explained — the spatial straight-line mechanism behind deployable solar arrays, scissor lifts, and folding optics. With formula and worked example.
Swinging-block Linkage
Swinging-block linkage explained — how this slider-crank inversion drives quick-return motion in shapers, planers, and packaging machines, with formulas and a worked example.
Spring-return Treadle to Pulley
Spring-return treadle to pulley converts foot strokes into shaft rotation via a crank and return spring. Sizing, formulas, and real workshop examples.
Slotted Main Crank with Elliptical Pin Orbit
Slotted main crank with elliptical pin orbit explained — geometry, motion equations, and a worked example for textile loom batten drives at 220 RPM.
Modified Slotted Crank with Link
Modified Slotted Crank with Link explained — how the slotted lever and connecting link convert rotation into asymmetric reciprocation in packaging and printing machines.
Bell-crank with Connecting Rod
Bell-crank with connecting rod explained — how the right-angle linkage redirects motion, sizing math, and worked examples from aerospace flight controls.
Ross Yoke Mechanism
Ross yoke mechanism explained — how this slotted-yoke linkage replaces the connecting rod in opposed-piston engines, with formulas, tradeoffs, and a worked Stirling example.
Oscillating Column (form 1)
How the Oscillating Column (form 1) converts continuous rotation into limited swinging motion — with formulas, tolerances, and real machine examples.
Gyrating Lever Transmission
Gyrating Lever Transmission explained — how the orbiting lever transmits power, where it appears in agricultural and pumping machinery, with formulas and a worked example.
Gambrel Joint Linkage
Gambrel joint linkage explained — how the folding two-bar knee joint transmits power in barn doors, prosthetic knees, and folding aircraft wings. Specs included.
Stephenson Topology Six-bar Linkage
Stephenson topology six-bar linkage explained — how it works, kinematic equations, and real applications in packaging, automotive seats, and industrial machines.
Rhombic Drive
Rhombic Drive explained — how Philips' Stirling engine linkage cancels vibration, balances pistons, and powers cryocoolers in aerospace and lab applications.
Jansen's Linkage
Jansen's Linkage explained — how the 12-bar Theo Jansen leg works, foot-path geometry, design formulas, and worked examples for walking robot builders.
Hart's Exact Straight-line Inversor
Hart's Inversor draws a true straight line from rotary input using a 6-bar antiparallelogram linkage. Used in precision metrology and optical alignment rigs.
Four-bar Linkage
Four-bar linkage explained — how the crank-rocker geometry works, Grashof's rule, coupler curves, and real applications in automotive suspension and robotics.
Evans Grasshopper Linkage
Evans Grasshopper Linkage explained — how this approximate straight-line mechanism guides a piston rod cleanly without crosshead rails in steam and lab gear.
Drag-link Mechanism
Drag-link mechanism explained — how the double-crank four-bar converts steady rotation into variable-speed rotation for industrial shaping and indexing machines.
Chebyshev Linkage
The Chebyshev Linkage converts rotary motion into near-straight-line travel without slides. See how it works, the formula, and real applications in robotics.
Cardan Straight-line Mechanism
Cardan straight-line mechanism explained — how the gear-in-gear hypocycloid produces exact linear motion, with worked example and applications in precision machinery.
Slotted Vibrating Bar to Horizontal Bar
How the Slotted Vibrating Bar to Horizontal Bar mechanism converts oscillation to linear travel. Formula, worked example, and real applications in automation.
Six Radial Grooved Trammel
Six Radial Grooved Trammel explained — how the slotted disc converts rotation into reciprocating motion, design rules, and examples from textile and packaging machines.
Rocking Arm
Rocking Arm mechanism explained — how it converts rotation to oscillation, sizing formulas, real machine examples in textiles, printing, and packaging.
Pair of Toe Levers
Pair of toe levers explained — how this dual-pedal motion control mechanism works, sizing formula, worked example, and real industrial applications.