Hi, i own a Kilppermate stringing machine and I string racquets for my high school tennis team. My friend wants me to try and use Babolat RPM Blast 17 strings, but I always run into trouble trying to string it. I mostly have trouble on the mains because the strings keep breaking on me. I now know polyester strings don't stretch much, but it would be nice to get some advice from people that have strung racquets with this string. Iv'e tryed to search the web for an answer, but i can't seem to find one. If you have any advice it would really help alot.