Making a catapult

Over the summer, at the Pathway to Adventure weekend summer camp for Cub Scouts, Johnathan and I made a catapult:

I decided this would be the next project for our Bear Den. We need to make something out of wood, it doesn't involve any glue, and I've already made it.
Of course, I turned to the CNC to mill the triangles. The 1/4" dowels go all the way through the side triangles, which is a bit of a shame, because the top can be squeezed a bit. In my model the holes for the dowels don't go all the way through, so they sit more tightly against the triangles. It does make it harder to cut the dowels to the right length.
I decided to be a bit aggressive on the milling parameters, but everything worked. On 1/2" plywood I used a 1/4" bit, a feed rate of 1000mm/minute. and 1/8" depth cuts. I was surprised that it came out so with that deep and fast of a cut, but there were no skipped steps.