Recent Blogs
Haven’s Planetary Crank Gear: Slotted-Cross Animation and Calculator
Explore Haven’s bicycle crank with equal external gears and a rocking slotted cross. Calculate output speed, instantaneous ratio and sliding-block position.
Half Hitch: Rope Strength Assumptions Calculator | FIRGELLI
Understand half-hitch rope contact and compare an assumed retained breaking strength with a factored line load. Results do not rate knot security or working load.
Full-rigged Ship: Yard Bracing and Geometry
See a three-masted square rig and how its yards turn. Compare two brace angles and calculate yard-end movement and angular allowance.
Full-rigged Brig: Sail Plan and Yaw Moments
Explore a brig’s two square-rigged masts and aft spanker. Compare yaw moments from two entered sail-force resultants and their lever arms.
Full Schooner Rig: Sail-force Projection Calculator | FIRGELLI
Explore a schematic schooner sail plan and compare ideal forward force from apparent wind, area and assumed coefficients. Understand why this does not predict boat...
Freight-Car Truck: Static Wheel and Axle Loads | FIRGELLI
Explore the bolster, side frames, springs and friction wedges of a freight truck, and calculate equal static wheel, axle and truck loads.
Freight Locomotive: Wheel–Rail Adhesion Calculator | FIRGELLI
Estimate an ideal adhesion limit from powered axle count, axle load and an assumed wheel–rail coefficient, with clear distinctions from locomotive ratings.
Floating Lighthouse: Light Range and Mooring Geometry | FIRGELLI
Explore how lightships mark offshore stations. Calculate geographic range in nautical miles and compare simple line geometry with its practical limitations.
Fisherman’s Bend: Assumed Rope-Strength Comparison | FIRGELLI
Explore an anchor-bend rope attachment and compare assumed retention percentages and design factors. Outputs are arithmetic comparisons, not rated working loads.
Figure-Eight Knot: Forms and Assumed Strength Comparison | FIRGELLI
Compare assumed rope-strength retention and load arithmetic. Learn the distinction between figure-eight forms and why the outputs do not certify a rope system.
Feathering Paddle Wheel: Ideal Angle-Schedule Calculator | FIRGELLI
Explore pivoted paddle floats and an ideal eccentric angle schedule. Compare wheel diameter, entry angle, stroke angle and the calculated eccentric offset.
Endless Cable Grip Car Mechanism: How the Grip Jaw, Haulage Rope, and Lever Linkage Work
Explore a mining cable-grip car with a fixed lower jaw and moving upper jaw. Compare hand force and opening travel through an ideal lever ratio.
Electric Tricycle: Layout Animation and Battery-Current Calculator
Explore a front-hub-drive electric tricycle and compare battery-side current with an entered controller limit. Speed and range are not calculated.
Electric Phaeton: Internal Wheel Gears and Road-Speed Calculator
Explore Hiscox’s open electric phaeton with internal wheel gearing. Compare ideal wheel and road speeds from two motor speeds, reduction ratio and wheel diameter.
Electric Brougham: Internal Wheel Gears and Battery Voltage Calculator
Explore Hiscox’s enclosed electric brougham with under-floor batteries and internal wheel gears. Compare ideal voltages for equal series and parallel cell groups.
Elastic Wheel Mechanism Explained: How It Works, Parts, Deflection Formula, and Real-World Uses
Explore a spring-spoke wheel under radial loading. Compare ideal deflection and stored energy using whole-wheel stiffness, with a separate circle-chord calculation.
Double Knot: Loose Double-overhand Diagram and Rope-length Calculator
Inspect a loose double-overhand rope knot in a rotating 3D diagram. Adjust rope diameter and proportions, and calculate the displayed centerline length.
Detachable Link Chain Mechanism: How the Hook-and-Bar Joint Works, Parts, Uses & Formula
Explore formed-steel hook-and-bar chain articulation and calculate net pull, mean shaft torque, mean rpm and pitch diameter from drive inputs.
Deep-sea Sounding Ball Mechanism Explained: How Brooke's 1854 Detachable Trigger Works
Watch a Brooke-pattern sounder release its weight and recover the sampling rod. Separately compare buoyancy and terminal speed for an equivalent sphere.
Variable-pitch Propeller: Blade-angle Interpolation
Explore a hydraulic pitch hub and interpolate blade angle between entered fine and coarse endpoints. Thrust, torque, governor response and actuator loads are not calculated.
Club Topsail Rig Mechanism Explained: Parts, Diagram, Sail Area Formula and Worked Example
Explore a triangular club topsail above a gaff. Calculate flat cloth area, leech length and separate spar extensions; these dimensions do not establish rig strength...
Clove Hitch Mechanism Explained: How It Works, Parts, Capstan Formula, Uses & Diagram
Trace the clove hitch’s two turns and crossing segment. Compare ideal capstan friction separately, with clear limits on knot strength and tail security.
Chain Stop Mechanism Explained: How It Works, Force Diagram, Parts and Uses
Explore a pivoted pawl that holds a chain. A separate static-span calculator compares horizontal reaction and segment tension from span and loaded vertical drop.
Carrick Bend Knot Mechanism: How It Works, Diagram, Parts, Uses, and Strength Formula
Inspect the Carrick bend’s interwoven rope paths. Compare entered strength assumptions and pull against an illustrative limit; the calculation does not rate a real knot.
Streetcar Truck: Pivot-Angle and Static-Load Calculator | FIRGELLI
Compare ideal truck swivel on a circular curve and equal static wheel loads. Enter pivot spacing, curve radius, total weight and a comparison angle.