Tortoise – possible developments

Fri, 27 Jul 2012

The turning turtle project is an idea that I've been thinking about for a while. This picture, from the workshop notes blog shows my original plan. I made up a rough prototype at the time but it didn't work as well as I had hoped. The mechanism itself worked but with the speed of turn of the turtle, it was hard to see the leg movement. At the time I thought about gearing the rotation down so that the legs moved up and down at the same speed but the tortoise turned at one quarter revolution per handle turn. It was all getting a bit complicated.
When I made the ninety degree joint I was looking for a character to add to the top of the box and I remembered the Turning Turtle idea. To keep things simple I didn't try moving the legs.  


Following up from the anonymous comment in the Turning Turtle project, there are a few ways that the project could be extended using the ninety degree joint as a starting point. Visit the previous blog post and check out the second comment

Two possibilities that I'll look into (when I've finished the Acrobat project). First picture, like the original idea, the legs are connected to a cam surface via cam followers. Perhaps if I increase the range of leg movements it will work better. The second possibility, fix the body so that it doesn't rotate. Inside the body, rotate a cam surface so that the legs, head and tail waggle up and down frantically.

Thank you anonymous commenter. These look like interesting ideas!

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Comments (3)

  • frankenpaper July 28, 2012 at 1:37 am

    Yes, Please! I have

    Yes, Please! I have confidence that you will find a way to get the head, tail, and legs all waiving whether the body is rotating or not. What if the wavy cam was attached upside down? What if you have a rotating drive shaft inside a stationary center post? The stationary center post could be like an umbrella or mushroom with the wavy cam on around the outer edges. Of course the rotating shaft will poke through the center of the "mushroom cap". I hope that makes sense. This way the body still rotates like the original. The weight of the legs stay on the outside where it naturally is. The legs are attached to the shell by a simple pendulum hinge. And the mushroom cam pushes down and lets up as the whole thing rotates. 

    Perhaps I have overlooked the roll that friction will play in all of this. So maybe I am just ranting. No mater what, I am looking forward to seeing magic that you will bring out of simple card stock. Good luck. 

  • Anonymous July 28, 2012 at 2:16 am

    Hi Rob i was thinking that

    Hi Rob i was thinking that you could make a tube that conects to the stand whith the wavy cam conected to it like in your second possibility picture  and the crank goes through it and glues to top of shell so the shell still goes round i did make a picture of what i mean but i don't know how to include pictures on this .

  • cool022883 July 28, 2012 at 4:13 am

    maybe for the new project you

    maybe for the new project you could change the character slightly that way its sort of a difrent model  maybe with a free little changes you could make it a crab or a lobster or even make a little color change and a few modifications you could make it more like a sea turtle     b   

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