Tappety tap

Fri, 11 Nov 2011

Whilst on a surly theme I'm revisiting an idea from my notebook-of-ideas.

I've had this idea in the back of my mind for a few weeks. Its a pendulum powered model. Tap the box and the character taps his foot impatiently whilst looking at you disapprovingly.

It would only need one foot to be driven for it to look quite effective. I'd want the foot to be flat to the floor if the model wasn't moving, ie with the pendulum in its rest position That means that with the pendulum swinging one way the foot would lift up but as it travels the other way the foot would stay still.


Here's a couple of possible ways that the foot could be driven on both swings of the pendulum. Two drive pins both lift the foot up. In the left hand layout as the pendulum swings to the right it lifts the left hand drive pin, when it swings left the other drive pin is lifted. The advantage of this more complicated layout is the longer horizontal pieces can lift the drive pins and foot higher.

The right hand layout is simpler, with fewer joints and hence less friction. The downside being that the horizontal parts on the pendulum are short so the lift will be less. 

Next step, try them both out, see which works best. Just a wild guess, I think I'll end up with yet another design which I haven't yet thought of!