Where the shelf is cut plays along with your limb length and tiller.
In order for the lower limb to be a little bit stronger than the top limb, it must be a bit shorter. One way to look at it would be to have your arrow shelf cut at the center of the riser, and then measure your limb length from the ends of the fadeout.
Another way to look at it would be to find the center of the bow, which usually falls in the grip area, and locate the arrow shelf somewhere above that point.
If you haven’t started working on the bow yet, you may want to check out bingham projects website. They have some informative video’s on building bows. Plans too.
Hunting the Osage Bow by Dean Torges has some good diagrams that help to explain the relationships between the grip and the limbs and tiller. But Dean doesn’t believe in arrow shelfs, so you won’t get specific help locating it from his book.
