I know it's not your question, but bite the bullet and get a StewMac template... I tried to make my own, and believe you me, it was a waste of time. I blew almost a year on that alone before I went out and bought a template. From there it took off.
I suppose if you could mill one, you might be able to get away with it, but something tells me if you don't have a router, you probably don't have a mill...