Geneva Stop

Fri, 1 Oct 2010

The Geneva stop is named after the city of its invention where it was used in the construction of clocks.
The Geneva stop is used to provide intermittent motion, the orange wheel turns continuously, the dark blue pin then turns the blue cross quarter of a turn for each revolution of the drive wheel.
The crescent shaped cut out in dark orange section lets the points of the cross past, then locks the wheel in place when it is stationary.
The Geneva stop mechanism is used commonly in film projectors to move the film on one frame at a time.

Comments (5)

  • nessabug12345 April 17, 2011 at 1:27 pm

    WHAT KIND OF MOTION DOES

    WHAT KIND OF MOTION DOES IT

    MAKE IF ANY?

    • robives April 17, 2011 at 7:13 pm

      Intermittent. The blue wheel

      Intermittent. The blue wheel turns quarter of a turn for each turn of the orange wheel. Notice that the blue wheel is stationary for much of the rotation of the orange wheel. 

  • Anonymous February 5, 2013 at 5:40 pm

    Could you give an example of

    Could you give an example of when this would be used?

    Geneva stops are used for intermittent motion, the classic example is in film projectos where the film needs to be moved forwards one frame then held still as the projection light shines through it. – RI

  • Anonymous August 3, 2013 at 8:43 am

    aside from a film projector

    aside from a film projector where does a intermittent motion mechanism is used?
    please answer this:D

    I’ve seen them used in powered looms. Also, the geneva stop, as opposed to drive, is used in watched to limit the number of times the winding handle can be turned so that the spring is not over tightened. – RI

    • Anonymous January 6, 2014 at 7:33 pm

      One use is for photographing
      One use is for photographing 360 degree views of an object on a rotating platform. The pause allows a photo to be taken of the object at rest, to eliminate blurring. By adding a second pin or cam that triggers a switch to take the picture, the whole thing becomes automatic, which becomes an important consideration if you are taking, for example, 72 frames (i.e. 5 degrees apart), especially if each frame is made up of focus-stacked, exposure bracketed shots, which can be anywhere from 6 to 36 or more shots per frame.

      Here are a few more, in the KMODDL library:
      http://kmoddl.library.cornell.edu/model.php?m=239
      http://kmoddl.library.cornell.edu/model.php?m=481

      …and an excellent tutorial:
      http://kmoddl.library.cornell.edu/tutorials/10/

      Hope this helps!
      Keith

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