Ada pendulum experiments

Wed, 9 Jan 2013

Further experiments on the theme of pendulums. I really wanted to create a pendulum powered model that bobs up and down when it is moved. Obviously, the first person that sprang to my mind when thinking about this possible mechanism was Ada Lovelace, mathematician and steam-punk computer programmer. And so we have, forthcoming project of a pendulum powered Ada Lovelace who bobs up and down whenever she is moved. Perfect.

Okay, mechanism time.

If I could use springs a vertical moving pendulum would be trivial but with card it is less straight forward. I need to convert the back and forth movement of a pendulum into up and down movement, and all within the space of Ada's conical section skirts.

My first draft is shown below with a bit of explanation as to why it was unsuitable. And so onto mk2. The go-to mechanism to change direction of movement by 90 degrees is the bell crank. The problem (there is always a problem, that is where the fun comes in :-)) being that the bell crank necessitates extra width in the model, making it hard to fit everything under the skirts. Above right and centre are my proposed solutions. Firstly, a pendulum with a cut out in the centre. Secondly, a bell crank that doubles back through the hole in the pendulum wrapping the mechanism neatly in on itself.

Notice also that I'm linking to the end of the main pendulum so getting the maximum amount of movement from any swinging going on. 

I have bits cut out and ready to go – I'll be reporting back in the tomorrow.

Here's one that didn't work.

Well, it did work but it is far too bulky. 

In this mechanism, the pendulum and the bell crank are a single piece. To get a reasonable amount of vertical movement the side arm needed to be long making the project over wide. To minimise the width I moved the pendulum right over to the side which also meant that the whole thing was unstable. Pah.  

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Comments (8)

  • umehta January 11, 2013 at 3:36 am

    Hello Rob,
    While Ada


    Hello Rob,

    While Ada Lovelace is no doubt a very respectable figure, a dolphin, half deep in water, would make more sense with this new venture mechanism. 

    You try to move it and it, perhaps when smiling, begins to bob up and down as if playing with you. And if there are two dolphins or taking turn to come out…

    An excellent idea! Thanks! – RI

    • Smelter January 11, 2013 at 9:16 am

      This could take “ages”, but

      This could take "ages", but don't get me started.

      • waterrocketsrule January 12, 2013 at 6:22 am

        On a cam follower i always

        On a cam follower i always have to use a little weight but i tried the Flex in the flex joint as a spring  next to the cam follower an it works great . it pushs the follower tight  on the cam !!!! i really like this i hope it helps


  • waterrocketsrule January 12, 2013 at 5:12 am

    Hi Rob you were talking about

    Hi Rob you were talking about you wish you could use springs what about the flex part in Flex Joint it works an acts like a spring. I was just wondering if that would help.

  • Smelter January 13, 2013 at 12:56 pm

    Now here is a pendulum I

    Now here is a pendulum I would love to see !!!



  • cool022883 March 19, 2013 at 8:55 pm

    wonder if rob forgot about

    wonder if rob forgot about this project=)

    Nope, I’ll have a couple of pictures upo shortly, the project has changed somewhat though. Now a paper poseable – RI

    • cool022883 March 20, 2013 at 5:30 pm

      nice i like the paper

      nice i like the paper poseables too =0)

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