CROSSBOW

If you can find a copy, "The Crossbow", by Ralph Payne-Gallwey is to some extent a project book, with enough information to make two or three different designs including a real windlass-drawn medieval warbow. Of course sending to Trieste to have the bow made may be a bit of a hassle these days . . .

Note that car springs are a good idea in principle but they're horribly light for crossbow use. A spring leaf off an 18-wheeler is more in the ballpark.

Shoudl be easy to find - it's reprinted regularly.

Here's a 1/8th scale model of an onager from the book.

I also made a 1/10th model for my son.