Recent Blogs
Valve-motion Eccentric: Ideal Projection and Speed Calculator
Calculate the ideal projection of a rotating eccentric center from throw, crank angle, advance and shaft speed. Actual strap, rod and valve motion are not...
Meyer Expansion Valve: Cutoff Kinematics Calculator | FIRGELLI
Explore a harmonic relative-motion model for a Meyer riding cutoff. Calculate closing crank angle and ideal piston travel with a finite connecting rod.
Tappet Lever Valve Motion: Assumed Opening-flank Calculator
Explore an assumed simple-harmonic follower rise, constant lever ratio and entered clearance. Results are ideal travel, not valve timing or flow predictions.
Eccentric Crank Mechanism Explained: How It Works, Diagram, Parts, Formula and Uses
Eccentric crank explained — how the offset shaft converts rotary motion into reciprocating linear motion in pumps, presses, and steam locomotive valve gear.
Slide Valve Mechanism Explained: How It Works, Diagram, Parts, Port Timing & Steam Engine Uses
Explore D slide-valve admission and exhaust connections, and calculate nominal full-port travel, eccentric throw and linear advance from selected port and lap dimensions.
Single D Slide Valve Mechanism: How It Works, Parts, Lap and Lead Diagram
See how a D-slide valve alternates admission and exhaust through three passages. Compare selected eccentric radius, throw and opening-span dimensions.
Simple Reversing Gear Mechanism Explained: How It Works, Diagram, Parts, Uses & Stop-Angle Formula
Simple reversing gear flips a steam engine's rotation by shifting valve events. See how loose-eccentric and slip-link designs work, with worked example and specs.
Meyer Cut-off Valve: Right-and-Left Screw Adjustment
Explore the Meyer riding cut-off plates and calculate their symmetric spacing change from opposite-hand screw lead and adjustment turns.
Marshall Valve Gear: Suspension-Link Topology and Eccentric Motion
Explore Marshall radial valve gear and its suspension link. Calculate the driving eccentric center displacement, speed and acceleration; valve events are excluded.
Gridiron Slide Valve: Port Opening Calculator | FIRGELLI
Compare gridiron and single-port opening displacement. Calculate travel saved for equal-length ports, with a schematic animation and worked area example.