Is there a specific reason you need bias binding? It's lots easier to make straight grain binding if you don't need to go around curves. Very few quilts before 1920 had bias binding (indeed Barbara Brackman, the renowned quilt historian, says she has seen only one case of bias binding prior to 1900). There are those who believe that bias binding wears better. Personally I am not one of those. I've been making, using, and washing my quilts for 30 years and have had no binding failures.
Jan in VA