Boy, talk about STICK-TO-IVENESS,  you get the prize.   
Dang, I'd hate to break twelve in a row.   How are they breaking?  Where?  are you stressing them too early, i.e. before they are planed/filed/scraped and READY to bend?  
hmmm........stick with these guys, ask lots of questions and , yes, we like pics.  It's that or ten thousand more words.  Need info, though: what wood are you using?  length of bows?  pull weight you are aiming for?  
looking forward to getting you out shooting one of yours!!
piper