All sorts of bits and pieces today, some more successful than others. Starting with…
For the pyramid model, I'm working on a mechanism that will turn the top of the pyramid through ninety degrees. I put this together based on the internals of a retractable pen. Two problems, the pens I looked at were divided into six rather than four, that and the fact that the pen is driven by a spring makes the action far more positive in the pen than in the paper model. Back to the drawing-board.
My next thought was to drive the top round with a couple of quarter circle gears. I'm now wondering if the parts of this would be better based on the bevel gear model. Its all looking a bit over engineered so I've put it to one side while I think about it.
While I'm thinking about the pyramid model I thought I'd make a chain model to add to my collection of paper mechanisms. Starting with a pinion…
I made a box to hold a couple of pinions then added a 'chain' made from a folded strip of card with holes matching the teeth on the pinions.
The result works well. I might try this with different size wheels to see if it works.
…and to finish off. A pair of fat pants, ready to fit with some hairy legs.