The Triceratops Mechanism is perhaps more of a starting point than a finished project though I decided to share it in its current state because it is a really rather satisfying mechanism.
The head is linked to the body via a two axis joint. A joint that is free to move side to side as well as up and down.
The head is fitted to the front of the joint and connected to a pair of bell cranks at back of the body via a pair of linkages. Moving both bell cranks in the same direction makes the head move up and down. Moving them in opposite directions makes the head move from side to side.
Because of the geometry of the linkages they also need smaller version of the two axis joint on each end to stop the model from either locking itself up or ripping apart.
The project in its current iteration is available for you to download and make from the www.robives.com website or if you are a paid subscriber to this newsletter you can download it for free from the end of this page. The pdf contains all the parts ready to print out onto thin card as well as a full set of step by step instructions. Thanks for your support!
Taking this mechanism as a starting point I have a couple of ideas for future projects. Originally I was intending to make the project as a triceratops automata project.
This is why the project has the the bell cranks at the end. I planned to link them to a pair of cam followers, add a reduction gear and have a sort of curious triceratops that looked inquisitively this way and that. I’m still planning to go ahead with the automata project so that is one to look out for.
While I was playing with the project in its current stage I had the idea of keeping it roughly as it is but adding a joystick at the back to control the head movement. It turns out that this isn’t as straightforward as I had originally thought and is going to require some sort of Ingenious Mechanism™. Should be interesting!
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