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.
The Wedge: Ideal Geometry and Force-ratio Calculator
Explore a symmetric wedge and calculate its included angle, displacement ratio and ideal per-face lateral force. Friction, cutting and material failure are not modeled.
Resolution of Suspension: Ideal Two-leg Tension Calculator
Resolve a centered static load into two equal leg tensions using the included angle. The tool illustrates equilibrium and does not select rigging or establish...
Spanish Windlass Mechanism: How It Works, Diagram, Formula, and Rigging Uses Explained
How a Spanish Windlass works — the rope-and-stick tensioning mechanism used by riggers, arborists, and sailors to generate huge force from almost nothing.
Rope Twist Lever (Spanish Windlass) Mechanism: How It Works, Diagram, Formula, and Uses
Rope twist lever explained — how Spanish windlass tensioning works, the force formula, and real worked examples for rigging, arborist, and shelter applications.
Rope Grip Hook Mechanism Explained: How It Works, Parts, Wedge Friction Formula and Diagram
Rope grip hooks lock onto a rope under load and release when slack. Learn the physics, sizing formulas, and rigging examples used in arborist and...
Lifting Jack: Rotating-Screw Animation and Work-Ratio Calculator
See how a rotating screw moves through a fixed nut. Compare handle path, screw lead and entered efficiency to calculate an idealized axial-force ratio.
Lever Windlass Mechanism Explained: How It Works, Diagram, Parts, Formula and Uses
Compare the ideal lever-to-drum radius ratio and reciprocal hand-to-rope travel. The animation shows rope take-up and the holding pawl during handle reset.
Lever Sector: Circular Sweep Animation and Arc-Length Calculator
Calculate circular sector arc length, endpoint chord and travel per degree from radius and sweep angle. See the fixed-radius motion in an interactive animation.
Lever Safety Trip: Hiscox Forms 48a and 48b Viewer
Compare two historical lanyard-operated throttle-valve trips. View their armed and pulled lever positions and follow the valve-release connections.
Lever Paradox: Hiscox Item 10 Balanced-Linkage Viewer
Explore the lever paradox with a connected double-beam diagram. Compare three illustrated postures and equal-weight relationships without a structural capacity claim.
Lever and Ratchet: Ideal Force Ratio and One-Tooth Indexing
An ideal lever-force comparison with an animated ratchet cycle that separates drive, holding and reset phases without implying a product capacity.
Inclined Plane: Sliding Force and Work Calculator | FIRGELLI
Calculate constant-speed uphill force and work from mass, rise, slope length and an assumed sliding-friction coefficient. Includes the ideal force-distance relationship.
Rope End Mechanism Explained: How Whipping, Splices and Heat-Seal Terminations Work
Rope End explained — how to terminate, splice, and seize hemp and synthetic rope ends for rigging, sailing, and arborist work without losing rated load.
Wire Rope Clip and Thimble: Parts and Rating Limits | FIRGELLI
Explore a wire-rope eye schematic and understand the separate roles of clips and thimble. Illustrative dimensions do not determine assembly strength or working load.
Compound Weight Motor Mechanism: How It Works, Diagram, Parts, Formula and Uses Explained
Explore three falling weights on a continuous rope. Calculate ideal rope tension, drum torque and the torque change through two optional gear stages.
Chinese Shaft Derrick Mechanism Explained: How It Works, Parts, Diagram and Mechanical Advantage
Explore a differential windlass with overhead guide sheaves. Calculate ideal force multiplication, input torque and bucket rise from the two drum radii and handle effort.
Chinese Windlass Mechanism Explained: How It Works, Diagram, Formula, Parts and Uses
Compare two drum diameters on one shaft. Calculate ideal hand force, shaft torque and rise per turn, and see why closer diameters give slower lift...
Block and Tackle Mechanism: How It Works, Parts, Formula, and Mechanical Advantage Explained
How a Block and Tackle multiplies lifting force using rope and pulleys. Mechanical advantage formulas, rigging examples, and real sailing and crane applications.
Ideal First-Class Lever: Moment Balance and Mechanical Advantage
An ideal first-class lever calculator for perpendicular moment balance, mechanical advantage, load force and the force-versus-travel tradeoff.