I've been experimenting with the pendulum mechanism that I'm using in the forthcoming dragonfly. I'm wanting to make the pendulum move faster to make the wings flutter faster. In the current model (left) the coin is hanging vertically and the centre of gravity it roughly 30mm from the hinge. To make the pendulum swing faster I need to move the coin closer to the hinge. Also, there is a problem with design in that the hinge, because it is horizonal, tends to peel apart because of the weight of the coin.
To move the coin closer to the hinge I have rotated it by 90° so that it lies flat. I've also made the hinge vertical, that way it wont peel apart. Two birds, one stone. The pendulum length is now roughly 7mm, about a short as I can get it I reckon!
This is what it looks like in position
and here is the top view showing where the wing linkages attach. One nice side effect of this design it the base can be really thin, as little as 20mm.
Ooo look! 400th blog post on robives.com