Recent Blogs
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 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.
Proportional Compasses Mechanism: How They Work, Parts, Ratio Formula & Uses Explained
Proportional Compasses scale drawings up or down with one slide adjustment. Learn the geometry, ratios, and real draughting uses from architects to model-makers.
Trammel for Drawing Ellipses: How the Archimedes Mechanism Works, Parts and Uses
How a Trammel of Archimedes draws true ellipses for pattern-makers, sign carvers and toolmakers. Geometry, formula, worked example and tolerance rules.
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.
Hyperbola Scriber Mechanism: How It Works, Parts, Formula, and Drafting Uses Explained
Hyperbola scribers draw true conic curves for optics, drafting and stonework. See how the string-and-pin method works, with formulas and a worked example.
Helicograph Mechanism Explained: Parts, Archimedean Spiral Formula, and Drafting Uses
Helicograph explained — how this geometric drawing instrument generates precise helical and spiral curves for engineering, surveying, and pattern layout work.
Flexible Curve Scriber Mechanism Explained: Parts, How It Works, Diagram and Bending Formula
How a Flexible Curve Scriber traces irregular curves for naval architects, patternmakers and surveyors — bending mechanism, accuracy limits, and worked examples.
Ellipsograph Turntable Mechanism: How It Works, Parts, Formula and Diagram Explained
How an Ellipsograph Turntable draws true ellipses for draughtsmen, jewellers and pattern-makers — geometry, formula, worked example, and selection trade-offs.
Eidograph Mechanism Explained: Parallel-Bar Drawing Copier, How It Works, Parts, Formula, Diagram
Eidograph explained — how the pivoted-bar copying mechanism scales drawings, where it beats the pantograph, and how draughtsmen still use it today.
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.
Dotting Instrument Mechanism: How the Toothed Wheel Sets Dot Pitch on Drafted Lines
How a dotting instrument works, why draughtsmen used it for dashed and dotted lines, and how to spec wheel pitch for archive restoration and cartography...
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 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.
Centrolinead Mechanism Explained: How the Drafting Linkage Aims Lines at Off-Board Vanishing Points
The Centrolinead is a drafting linkage that draws lines converging on an inaccessible vanishing point. Used in perspective drawing, shipbuilding, and architecture.
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) 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.