Hi, I have yet to find a machine and their 1/4 inch foot with the guide sew a true 1/4 inch seam. I have had to file the single hole in the plastic part of the foot to make it more slotlike so that I could adjust the needle to get the correct size seam. Sometimes it has to do with the thread and fabric. Heavier fabric + thicker gauge thread will take up more space and offset the 1/4 inch seam. Pre-cut kits can be a nightmare. You must do a few practice seams to get the right size seam so that the add on pieces fit. Anne