External Geneva mechanism

Geneva Geometry Lab

Configure the wheel, pin, clearances, and bores. The drawing and manufacturing dimensions update together.

Geometry valid
Assembly view preview · Fusion 96-DPI exports are 1:1
Pin enteringOutput 0.0°
Centre distanceshaft centre to centre
Crank radiusdriver centre to pin
Index per cycleoutput rotation
Dwell per cycledriver rotation

Dimension schedule

DimensionValueRelationship

Design checks

    The solid blue wheel and raised orange lock cam share an interaction plane. The dashed carrier and crank arm run below the wheel and require axial spacing.

    Geometry basis and sources

    Base dimensions use the classical external-Geneva construction in Michael J. Rider’s Design and Analysis of Mechanisms. The release cut uses the same continuous-envelope principle described in Mechanism and Machine Theory. The separate raised locking rib and pin are also documented in US2625833A. Fabrication SVG coordinates are preconverted to Fusion’s 96-DPI pixel convention so scale 1.0 preserves the entered dimensions. Verify loads, tolerances, axial spacing, and fabrication method before manufacture.