this took me a long time to learn, but through sheer patience and persistance on many trad gangers part- it finally sunk in...
the whole center of the bow thang!
the center of your hand, should be in the center of the bow. ie the center of your hand, which is the centerline down your index finger( the proverbial birdie!!!)should more or less line up with the centwr of your fore arm.
so if your arrow shelf is contacting with the top of your first finger, that means on average( depends how fat your sausages are!!)your shelf should be about 1 1/4" above center. measure your own hand to see if these measurements match yer mitt, if not adjust them to suit.
so lets assume you want a 4 1/2 " grip section.(1 1/4 above center, and 3 1/4" below center)
so that in turn will ensure that your bottom limb is 2 inches shorter than the top limb( the difference between the above and below center handle section measurements)
still with me- remember this took me a while to get it!!!!
so with your bottom limb being shorter, it is going to work a little harder- so thats where the whole positive tiller technique comes into play.
basically the bottom limb is tillered a little stronger than the top limb.
i have built bows both ways- some with the arrow passing at center, and some with the arrow passing above center-
and this is what i observed,
when your hand is in the middle of the bow
( arrow pass above center) the bow is more stable in your hand- it doesnt want to tip a limb towards you, and draws back evenly and smoothly, and is more stable in its shooting.
but there are a heck of a lot 'o guys here that will/can help you, that have been building beautiful bows a lot longer than i have been building bendy stick things!!!