Two Questions

[D.A. Davis]

Do you measure bow length from tip to tip along the back, or belly, of the bow, or string groove to string groove along the back, or belly, of the bow?

How do you figure out the correct angle for the string grooves in the limbs?

[Focusource]

As for the string grooves, see    this post .  I will be cutting my grooves the way Eric Krewson shows from now on.

[Pat B]

I have used Eric's method with good results. When making wood bows each will be a little different so cutting the string grooves should be measured for that bow and Eric's method will give you the correct angle for that particular bow.
  I measure my bows from tip to tip and generally down the back. Most others measure from groove to groove. If you are buying a string the AMO standard is measured from grove to grove. I make my own strings so it doesn't matter.