Mechanisms — drafting tools

Recent Blogs

Proportion Compasses / Hyperbola Drawing diagram
Proportion Compasses / Hyperbola Drawing: How the Mechanism Works, Parts, and Drafting Uses
How proportion compasses and hyperbola-drawing linkages work, with the geometry, real shop scenarios, and a worked example for pattern-makers and drafters.
Section Liner diagram
Section Liner Mechanism: How the Pawl-and-Rack Indexing Works, Parts, Uses, and Hatching Formula
Section Liner explained — how draughtsmen use this drawing tool to hatch parallel section lines fast and consistently in mechanical and architectural drafting work.
Roller Parallel Ruler diagram
Roller Parallel Ruler Mechanism Explained: How It Works, Parts, Diagram and Marine Navigation Uses
How a Roller Parallel Ruler works, the geometry behind its tracking accuracy, and why marine navigators still use it on paper charts today.
Tracing Bar diagram
Tracing Bar Mechanism: How It Works, Parts, Formula, and Drafting Uses Explained
Tracing Bar explained — how draughtsmen and instrument makers use a sliding bar with a stylus to copy, scale, and transfer curves with sub-millimetre accuracy.
Parabola Drawing Instrument diagram
Parabola Drawing Instrument Mechanism: How It Works, Parts, Focus-Directrix Diagram and Uses Explained
How a Parabola Drawing Instrument traces true parabolic curves for optics, antenna dish layout, and architectural drafting — geometry, formulas, worked example.
Drawing Instrument (form) diagram
Drawing Instrument (form) Mechanism: How It Works, Parts, Diagram & Error Calculator
How a drawing instrument form works in technical drafting — geometry, tolerances, and accuracy targets used in engineering, cartography, and architecture.
Cyclograph diagram
Cyclograph Mechanism Explained: How a Trammel Ellipsograph Traces Ellipses, Parts and Uses
A cyclograph traces ellipses and curves on technical drawings. See how draughtsmen use it for shaft sections, cam profiles, and isometric circles.
Three Part Parallel Ruler diagram
Three Part Parallel Ruler Mechanism: How It Works, Parts, Geometry & Uses Explained with Diagram
How the Three Part Parallel Ruler transfers angles across a drawing board without slip. Components, formula, worked example for drafting and navigation work.
Parallel Ruler (form 6) diagram
Parallel Ruler (form 6) Mechanism Explained: Four-Bar Linkage Diagram, Parts, and Uses
Form 6 Parallel Ruler explained — how the four-bar linkage keeps the straightedge parallel during translation, with worked numbers for drafting and marine chart work.
Parallel Ruler (form 5) diagram
Parallel Ruler (form 5) Mechanism: How the Crossed Parallelogram Linkage Works, Parts & Uses
Parallel Ruler form 5 explained — the four-bar lazy-tongs linkage that lets draftsmen, navigators and CNC operators transfer parallel lines across a chart or drawing.
Parallel Ruler (form 4) diagram
Parallel Ruler (form 4) Mechanism: How the Four-Bar Parallelogram Linkage Works, Parts & Uses
Parallel Ruler form 4 explained — the four-bar linkage drafting tool used by navigators and architects to transfer parallel lines across charts and drawings.
Parallel Ruler (form 2) diagram
Parallel Ruler (form 2) Mechanism: How the Parallelogram Linkage Works, Parts, Diagram & Uses
Parallel Ruler form 2 explained — how the four-bar linkage holds true parallel motion across a drafting board, with formulas, tolerances, and worked examples.
Pantograph diagram
Pantograph Mechanism: How the Four-Bar Parallelogram Linkage Scales and Copies Motion
How a Pantograph linkage scales drawings, engraves nameplates, and copies CNC paths. Geometry, formulas, tolerances, and a worked example for makers and engineers.
Trammel of Archimedes diagram
Trammel of Archimedes Mechanism: How It Works, Diagram, Parts, Formula and Uses Explained
How the Trammel of Archimedes draws perfect ellipses using two sliders in perpendicular slots. Real applications in machining, drafting, and toy design.