Bunny Mechanics: Mechanism to download and make.

Wed, 17 Aug 2011

"Rob
Can you give me some clue as to how to make the attached rabbit move its head from side to side , and maybe move its ears. What kind of cams are required?.
Kind regards
Harry Davis."

Harry's picture is below left – my rather dodgy sketch of what I think he is after is on the right. Turn the handle and the rabbit shakes her head from side to side.

Here's one possible solution presented in the form of a mechanism to download and make. If you are a member you'll be able to download the parts from the usual place. I've created a box with a handle on the side and a vertical shaft protruding from a hole in the top of the box. Turn the handle and the vertical shaft flips back and forth. Perfect for driving the rabbit's head. Once the head is moving side to side it should be fairly straightforward to move the ears, perhaps by connecting them to the top of the fixed body with a linkage.

To make the mechanism you'll need to print out the pages onto thin card. (230 micron / 230gsm) score along the dotted lines then cut out the parts.


Fold up the bases on the two box parts to make triangular box sections.


Glue the two parts of the box together but don't glue the lower flaps down yet.


Glue the front of the lid on. Just the front – leave the three remaining tabs unglued for now. 

Fit the base into place, notice that it lines up with the bottom of the cut-outs front and back. Make sure that the hole in the base is lined up with the hole in the top.


Fold the two cams in half and glue them together to make them double thickness. Once the glue is dry, carefully cut round the pieces.


Glue together the two shafts.


Thread the two cams onto the shaft lining them up with the grey lines. Use the picture above to make sure that they are facing the correct direction.


Glue the striker plate onto the vertical shaft using the grey areas for alignment.


Glue the two washers onto the vertical shaft using the grey lines for alignment. 


Glue the two fillets into place as shown. These will stop the cam fingers bending over when they hit the striker plates.


Thread the drive shaft into the box. Glue on the washers lining them up with the grey lines. 


Thread the vertical shaft up through the hole in the box top. 


Fold the lid down and thread the bottom end of the vertical shaft into place. The flat back of the vertical shaft should be towards the back of the box as in the picture.


Front view.


Assemble the handle in three steps. Fold and glue together the two square section tubes. Fold up and glue together the two parts. Roll round and glue down the long tab to make a round handle.


Glue the handle to the drive shaft.


There you go Harry. I've provided the mechanism. Over to you for the rabbit. Have fun!


Check out an example of this mechanism in action here

Comments (2)

  • umehta August 23, 2011 at 6:13 pm

    Let me confess – I did not

    Let me confess – I did not order "Push Paper" (not enough budget!) but ordered "Amazing Paper Pets" and "Paper Automata" instead (had just enough to…)…and let me admit – both the books are really amazing. 'The amazing paper pets' has 6 models that you need not score or cut but simply pull out, glue and assemble. It is so easy… Not only that but it has the Push Paper winner entries – Bob the Dog (Barking Dog) and Goat. My favourites are the Gorilla and Kangaroo-mom with her kid. I don't dislike cha cha chickens and cat either…so folks, if you are ordering Push Paper and if you have budget, don't miss out these two books as well. If you have a limited budget, just go for these two books I mentioned. In either case, it is not worth missing on this 'joy' that Michael had mentioned on the other day.

    Rob,

    I know you are busy with Blender 2.5 but is is possible to run a paper bunny in it and present it to the community so as this little beautiful mechanism becomes a complete set like DAMH?

    Thank you in advance,

    Urmish

  • jackz October 10, 2014 at 8:21 pm

    I managed to make a polar

    I managed to make a polar bear whose head moves left to right for christmas.  Thank you Rob!!

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