I've been working on the catapult (as well as completing boring but necessary paper work) Having changed things around a little from the earlier version I can now fling an m&m around 3 metres. Not as powerful as I'd hoped, so I've been trying out different mechanisms. the Trebuchet, shown on wikipedia, uses rope to increase the power of the the throw. As the arm raises, the rope acts as an arm extension moving faster and further than the main arm greatly increasing the range. I really don't want to use string though, it doesn't seem right on a downloadable model. So I'm experimenting with an extend flailing arm. More details when I work out how to release the m&m.
Thanks to the people who emailed about my previous post, don't forget you can always leave comments rather than email. That way other website visitors can share in your wisdom!
Oh, and thanks to the people who pointed out that some of the pictures were missing from the daily newsletter. If you can see a picture here, I have worked out what the problem was.