Thanks for taking the time to do that Del. Just as a point of note, Yumi limbs are quite a bit different in length, yes, but they're also very, very different in their side profile in relation to each other, and to the handle. When you look at an unstrung Yumi, imagine the handle vertical or straight up and down in your hand, and then take not of the reflex in each limb and their tips location in relation to the handle. I think there's more about that design related to balance and tiller than we realize.
I've been trying to understand all the ins and outs of this limb balance and timing stuff and have also made test bows and equipment and recently altered my tillering tree, again. I'm not going to worry about the Yumi though until I get the easy ones completely figured out
As far as balance while moving the bow left or right on the tillering tree, as long as you pull down on the string from directly below the pivot/fulcrum point of the bow, it doesn't balance too badly. It's when the fulcrums on bow and string diverge, like when we move the string hand up so we can shoot the arrow from above the bow hand.... that's when imbalance occurs and the bow really tilts on the tree... and in the hand... unless we've made provisions in relative limb strengths.
