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One tooth turning a notched wheel one notch per turn, locked between (Geneva principle)

How does a single tooth give a locked, step-by-step motion? · Hardware · basis: Xem Studio design following Brown No. 68 (1868)

Also called: intermittent gear, geneva drive, one tooth gear, maltese cross, rueda intermitente de un diente (ginebra), Malteserkreuzgetriebe (Ein-Zahn-Schaltwerk)

Exact dimensions. True size, with no printing tolerance added.

sizes
5 in table

Notes

  • A driver with a single tooth (here a round pin) turns a wheel with notches: once per turn the tooth enters a notch and moves the wheel one division; for the rest of the turn the driver's plain rim sits in a concave arc of the wheel and locks it.
  • Drawn with the catalog 6-station Geneva pair (R30 wheel, pin at R17.32, centres 34.64 mm = R / cos 30°): the pin is at the bottom of a slot at mid-index. The wheel moves 60° in 120° of driver rotation and stands locked for 240°.
  • Brown's No. 68 (one tooth driving a notched wheel one notch per revolution, the blank part of the driver's rim locking it). Brown's Geneva stop (No. 212) is the watch-winding form.
  • Parts (each has its own page): geneva-drive, dowel-pins-metric.
  • Brown's movement No. 68 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

One tooth turning a notched wheel one notch per turn, locked between size chart

parametervalue
stations6
wheelR30, 5 mm slots
pin radius17.32 mm
centres34.64 mm
motion / dwell120° / 240° of driver turn

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Henry T. Brown (1868, public domain)Five Hundred and Seven Mechanical Movements — scan on archive.orgwebPublisher's page; dimensions are facts
507movements.comBrown's movement No. 68: figure, his text and an animationwebPublisher's page; dimensions are facts

Free files

★ Free files 1 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

single-tooth-intermittent-wheel-mechanism-assemblyAssembled mechanism, all parts placed at one pose (STEP keeps each part separate)STEP · STL
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
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Plain text: sheet.txt · JSON: /api/geometry?object=single-tooth-intermittent-wheel-mechanism

One tooth turning a notched wheel one notch per turn, locked between (Geneva principle), isometric render of a generated part
Render of single-tooth-intermittent-wheel-mechanism-assembly from the free STEP; not to scale.

Fits with

Geneva drive: 4 and 6 station wheels, R30, with drive discs, isometric render of a generated part
Geneva drive: 4 and 6 station wheels, R30, with drive discs2 sizes★ 4 files
Dowel pins, 2–6 mm (ISO 2338 / DIN 6325), isometric render of a generated part
Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)5 sizes★ 23 files

Questions

How does a single tooth give a locked, step-by-step motion?

A driver with a single tooth (here a round pin) turns a wheel with notches: once per turn the tooth enters a notch and moves the wheel one division; for the rest of the turn the driver's plain rim sits in a concave arc of the wheel and locks it.