Where did the set occur? All from one spot or was it spread uniformly? That tells you if you had a weak spot versus just the normal process of training the bow to bend. 2" of set is expected with a selfbow that has a reasonable design. As far as losing springiness, I suppose if you over-stressed the wood a bunch by pulling it past the intended weight on the tiller tree, you could fatigue it unneccessarily. Did you do that? The only other thing that comes to mind, is that once you get to the "sweet spot" you can make a big defference in weight with a very small amount of wood removal. And its quite easy to blow past this spot, because the process of getting to it requires mroe agressive removal. Its because the relationship between thickness and poundage isn't linear, its more nearly exponential (twice as thick, eight times as strong, to be exact).
A fellow who is experienced with yew bows, told me you can't have too much sapwood. Only too little. So I don't think that was a problem, although with a flatbow you might have been running out of heartwood on the belly side? You wouldn't want the belly to be sapwood.
Good looking billets. Keep at it, I broke my first yew bow so your maiden voyage beats mine.
