new guy from N. Il Making bows with a 7th grade

Hello. I've done a couple simple bows from Payne-Gallwey's book including the onager. I'm now teaching a Waldorf school 7th grade and have way too much leeway with the curriculum. They made hickory flatbows, and upon seeing one of my crossbows wanted to make one. I'm having them make stone bows, sort of a hybrid between the first and second ones found in the book. They have the wood working skills, and some of the smithing down. I'll be helping with the fiddley bits. The project will culminate ...