I agree with the others that you need to start with larger HSTs, but, since you have already cut all the fabric, trying truing up your HSTs to 2 1/4". I'm having the same problem right now, using Terry Akison's quick strip method for HST and some are way off base. I finally figured out that I have to trim them down to 2" and although I still have to compensate a few of them, it is working. I hope this makes sense to you. I do know one thing for sure, I won't be using that methoid again and I will go up to the next inch (ie 2 5/8 will be 3" ) and trim them to the size needed.