Cardan Gear

Fri, 1 Oct 2010

Invented by Girolamo Cardano in the 16th century the Cardan gear is a way of converting rotary motion into straight line motion. Watch how the red dot on the inner purple gear exactly follows the vertical dotted line. The outer gear has a diameter exactly twice as large as the inner gear. In the above example they have 40 and 20 teeth respectively. Cardano also invented a type of universal joint and investigated the mathematics of probability. Understanding the mathematics of risk helped him make a living from gambling until eventually he could find no-one to gamble with and had to move onto new pastures…

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Comments (12)

  • Anonymous May 23, 2011 at 7:26 pm

    some sort of answer to how it

    some sort of answer to how it works would be nice too help me get on with school work but cool website

    • littlemisszombie June 18, 2011 at 12:59 am

      ??????????? i do not

      ??????????? i do not understand your comment :/  because he  (rob) has said how it works???????

      i am loving this, my little boy loves making models, and i'm so glad i've found this πŸ˜€ when i get paid (soon) i'm going to buy membership πŸ˜€  when i was little i used to go to the village library, and constantly get out this book they had on automated toys and how to make them; it showed wooden toys, but i used to make them out of corrugated cardboard etc (hey it was the 80's :D) but this is brill!!!!!!!!! i just know that tomorrow, even if my little boy doesn't fully understand everything, he will just love the animation of it moving, and when i show him some of them with cereal box card etc he will be in his element….thanks for this site πŸ˜€ i can't get over it πŸ˜€

      • robives June 18, 2011 at 9:06 am

        Thanks! I must admit I didn’t

        Thanks! I must admit I didn't understand the comment so I left it to answer later.

        • littlemisszombie June 19, 2011 at 4:30 pm

          πŸ˜€ right, i want to buy some

          πŸ˜€ right, i want to buy some model kits of yours for my little boy off flying pig, or possibly off here dependant on the answer to this question please πŸ™‚ : on flying pig, do the kits come 'through the post' rather than download please?  the reason for wanting them through the post is because my printer is on the blink at the mo :/ so a postal kit (s) are what i want at the min πŸ™‚ i haven't necessarily asked about the kits on here, because i am guessing when not a member or are a member, all these are to download, which is great, but at the minute useless to me,lol, as i found out yesterday when i downloaded the crow and tried to print it even after loads of faffing the printer is the culprit not the download πŸ™‚ many thanks πŸ™‚

          • robives June 19, 2011 at 5:54 pm

            HiΒ @littlemisszombie, yes the

            Hi @littlemisszombie, yes the models on Flying Pig are printed models that arrive through the post. 

  • Anonymous June 23, 2011 at 3:52 pm

    how does it work and could u

    how does it work and could u put it in a toy

  • Anonymous September 28, 2011 at 9:35 am

    What are the speeds in the

    What are the speeds in the end points of the linear motion contra the speed of the middle part?

    The speed at the end points is zero, in the centre it is one, the speed varies between the extremities according to a sine curve. – RI

    • robives September 28, 2011 at 7:14 pm

      It looks like the speeds will

      It looks like the speeds will follow a sine wave. The end points will be speed zero with maximimum speed in the middle.

  • Katie Grace April 27, 2012 at 4:06 pm

    hiya rob
    great stuff!!! Β what

    hiya rob

    great stuff!!!  what project would you say is a good example of this cardan gear mechanism?



    The only place I’ve seen one in action was in a sewing machine raising and lowering te needle. – RI

    • umehta April 28, 2012 at 12:19 pm




    • umehta April 28, 2012 at 12:39 pm

      But to answer your question

      But to answer your question about what project may use this mechanism: 'Ornithopter' project uses cardan gear. Hopefully someday, Rob will design a paper ornithopter!

      That would be a fun project! – RI

  • Jose February 2, 2018 at 7:22 pm

    I think that this product is absolutely amazing. 10/10 πŸ™‚

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