Recent Blogs
External Geneva Drive: Index and Dwell
Explore an external Geneva drive and calculate index, engagement and dwell angles from slot count, plus the driver period from rotation speed.
Eccentric Cone Change-velocity (form 1) Mechanism: How It Works, Parts, Formula and Diagram
Explore an eccentric cone on an advancing screw. Calculate roller height, signed rotational speed, vertical velocity and axial sliding during one turn.
Slotted Cross-head with Sliding Journal Box: How It Works, Diagram, Parts, Formula and Uses Explained
Explore a slotted cross-head and sliding journal box with an animated calculator for stroke, position, velocity and acceleration.
Crank Substitute Mechanism: How the Planetary Gear Slider-Crank Works, Parts & Uses
Explore an internal-gear crank substitute. Compare the straight-line 2:1 case with changed tooth counts or pin offset, and calculate first-turn spans and peak pin speed.
Quarter-Turn V-Belt Drive: Gates Guideline Comparison
Quarter-turn Belt Drive explained — how the 90° twist transmits power between perpendicular shafts, design rules, and real industrial applications.
Geneva Drive (external) Mechanism Explained: How It Works, Diagram, Parts, Formula & Uses
Geneva Drive explained — how the external Geneva mechanism converts continuous rotation into precise indexed motion for film projectors, turrets, and packaging lines.
Tatham's Dynamometer: Ideal Moment and Power Calculator
Compare ideal reaction moment, inferred tension difference and rotational power from entered force, arm, pulley diameters and speed. No calibration is performed.
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.
Reversing Lever: Gear Direction and Pitch-Diameter Calculator
Compare direct and idler gear paths, understand their rotation directions, and calculate pitch diameter from tooth count and diametral pitch.
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.
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.
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.
Slider-crank Reversing Mechanism: How It Works, Diagram, Parts, Formula and Uses Explained
Slider-crank reversing converts continuous rotation into reciprocating linear motion. See how it works, formula, worked example, and shaper-machine uses.
Rack and Pinion Mechanism: How It Works, Diagram, Formula, Calculator and Real-World Uses
Rack and Pinion explained — how the gear-and-bar mechanism converts rotation to linear motion, with formulas, real automotive steering examples, and design tradeoffs.
Spiral Stop-motion Gear Mechanism: How It Works, Diagram, Formula and Indexing Uses Explained
Spiral stop-motion gear converts continuous input into precise stepped rotation for indexing turrets, watch movements, and automated assembly machinery.
Pin Wheel and Slotted Pinion: Three Selectable Speed Changes
How a pin-wheel and slotted pinion converts continuous rotation into stepped indexing motion — design rules, formulas, and real-world examples from packaging and watchmaking.
Mangle Wheel: Guided Pinion and Oscillating Wheel
Explore a guided-pinion mangle wheel. Convert entered pinion speed, tooth count, engagement pitches and output sweep into ideal count-based timing.
Flywheel Energy Ratio Calculator: How Speed Changes Storage | FIRGELLI
Compare flywheel energy at two speeds. Learn why energy follows speed squared, what the ratio means, and why usable energy differs from total stored energy.
Almond’s Flexible Metallic Tube: Two-Wire Construction and Interactive Diagram
Explore Almond’s round-wire and triangular-wire tube wall. Compare bore, pitch and joint allowance with clearly stated limits on the dimensional calculation.
Band Brake Mechanism Explained: How It Works, Capstan Formula, Parts, and Industrial Uses
Calculate band-brake tension ratio and limiting torque from drum radius, wrap, friction and slack-side tension. Explore a capstan example and model limits.