Recent Blogs
Post Crane: Declared Load and Boom Moment Ledger
A Post Crane is a fixed-mast jib crane for fence posts, utility poles and tower work. See how it works, lift formula, real applications and...
Post Auger: Exact Single-Start Helical Flight Geometry
Post auger mechanics for fence builders, utility crews, and solar installers — torque, flight geometry, soil class limits, and how to size a drive head...
Portable Steam Derrick: Ideal Reeving and Boom Geometry
Portable steam derrick explained — how the boiler, hoisting drum and guyed mast lift heavy loads on construction sites, quarries and rail yards.
Pneumatic Dumping Car: Exact Pivot-and-Cylinder Geometry
Pneumatic dumping car explained — how compressed-air tipping skips work in mining, tunnelling, and foundry haulage, with formulas, sizing, and real-world examples.
Package Elevator (VRC): Declared Two-Post Layout
Explore a material-only two-post VRC. Calculate equal landing spacing and rectangular carriage area and perimeter from entered layout dimensions.
Melan Arch Bridge: Embedded Steel Ribs and Ideal Arch Reactions
Explore the Melan system of curved steel ribs embedded in concrete, with a separate calculator for ideal three-hinged parabolic-arch support reactions.
Log Sawing Machine Mechanism: How a Bandsaw Mill Works, Feed Rate Formula, Diagram and Calculator
Explore a band head saw and log carriage. Calculate tooth-pass frequency and implied feed from band speed, teeth per inch and an entered bite per...
Lever Grip-Tongs: Hiscox Item 1461 Motion Viewer
See how shackle pull closes lever grip-tongs through their connecting links and upper arms. Compare three schematic positions without a lifting-capacity claim.
Hydraulic Pile Driver: Ideal Drop-Energy Calculator | FIRGELLI
Calculate ideal gravitational drop energy, free-fall speed and average energy rate. The model does not predict impact force, pile penetration or equipment capacity.
Four-Guy Mast Derrick: Gin Pole Motion and Guy-Force Calculator
Explore a mast supported by four ground guys, with a hoist at its head. Compare one guy’s tension and anchor uplift for an entered horizontal...
Expansion Anchor: Taper Displacement Calculator | FIRGELLI
Explore how anchor draw-in produces radial sleeve motion. Calculate ideal gap closure and displacement, separately from anchor capacity or installation torque.
Elevator Safety Gear: Wedge Geometry and First-Contact Calculator
Explore ideal wedge take-up in elevator safety gear. Calculate travel to first rail contact and a frictionless force ratio from ramp angle and per-side gap.
Conical Pug Mill Mechanism Explained: How It Works, Parts, Pressure Diagram and Uses
Explore a historical conical paddle mill. An independent calculator compares entered inlet and die pressures, their interval midpoint and pressure ratio.
Conical Mixing Barrel: Paddle-Shaft Animation and Calculator
Explore a stationary conical mixer with a rotating paddle shaft. Calculate total shaft turns, time per turn, unfilled capacity and vertical drop from inclination.
Concrete Mixer Mechanism: How Drum Mixers Work, Parts, Diagram and Mixing Formula Explained
Explore a transit-mixer drum with attached spiral blades. Calculate time for a selected revolution count and compare batch and geometric drum volumes.
Concrete Girder Bridge: Pretensioning Animation and Strand Stress Calculator
Explore precast concrete bridge girders and a conceptual pretensioning sequence. Calculate selected strand jacking stress from ultimate strength and a ratio.
Cement-testing Machine Mechanism: How It Works, Parts, Diagram and Uses Explained
Explore a hydraulic cube-compression frame. Calculate nominal compressive strength, geometric face angle and ideal load-ramp time from measured or assumed inputs.
Cantilever Hoisting and Conveying Machine Mechanism: How It Works, Parts, and Moment Diagram
Explore the Lancaster opposed-boom hoisting machine. Compare a suspended load’s bending-moment contribution at three reaches; machine stability needs separate analysis.
Cantilever Bridge Mechanism Explained: How It Works, Parts, Moment-Balance Diagram and Uses
Explore the load path of a balanced cantilever bridge. Compare one arm’s root moment from distributed load, tip reaction and added live moment, plus chord-couple...
Cable Hoist and Conveyer Mechanism Explained: How It Works, Parts, Reeving Diagram and Uses
Explore a travelling cableway trolley and ideal hoisting tackle. Compare per-fall rope tension and hook-to-rope speed ratio from total suspended mass and fall count.
Belt-driven Elevator Mechanism: How MRL Traction, Polyurethane Belts & Sheave Geometry Work
Explore a coated-belt traction elevator with two-to-one suspension. Compare belt bend geometry and sheave diameters; no elevator capacity or belt-life rating is calculated.
Balanced Riveting Machine Mechanism: How It Works, Parts, Formula, and Industrial Uses Explained
Explore orbital peen motion and residual rotating unbalance. Calculate excitation force and frequency; forming force, joint strength and machine vibration need separate analysis.
Automatic Disengaging Grip Mechanism Explained: How It Works, Parts, Formula, and Uses
Explore a schematic automatic gripping and release sequence with normalized load comparisons. The example values do not specify a lifting-device rating.
Automatic Balance Crane Mechanism: How It Works, Parts, Formula, and Uses Explained
Explore a moving-counterweight crane concept and compare ideal hook-load moments, position error and an illustrative reference band.
Arched Deck Truss Bridge Mechanism Explained: How It Works, Parts, Diagram and Uses
Explore a deck arch with a point load. Calculate rise and horizontal thrust, and compare the symmetric reference force with unequal left and right reactions.