If you have been basting all of your seams you may need to now go back and restitch them, or the whole thing might come apart. Each machine seems to have different settings for selecting stitch length, but, 10-12 stitches per inch should be about the longest stitch for piecing. When paperpiecing or other piecing that requires pulling on seams or cross cutting 12-16 stitches per inch are more secure, likely to hold up.