My needles keep breaking. I don't think the material is too thick for them or not. I'm sewing straps together for an asian baby carrier. I'm not doing any padding. Its a silk and cotton together. So its pretty thin material. I don't know what size the needles are because I borrowed the machine from a friend and their her needles. She hasn't used the machine in a few years so she let me borrow it. I'm putting in the needle the same way it says to. I'm wondering if maybe I'm not putting it in tight enough if that would make a difference. I was able to sew my first baby carrier but i went through two or three needles in the process. I want to make another one because I didn't like how the straps ended in the other carrier.