like jawge said... Set happens. You can't build a bow without damaging wood cells. The trick is to only damage the ones that have to be to damaged to bend the bow. Proper design for weight, moisture, and tillering are key to reducing set. Along with never overstressing the limbs, which damages wood fiber, also is a no no. Just go slow and make sure your limbs are built to handle the stress. For me, it all came to experience gained from this site, and personal failures and succeses. JMO though, I'm no expert.