If you've got a fairly modern machine, just check that you haven't got the needle position knocked off centre. It should only take a few pushes of a button to reposition your needle. All the quarter inch feet on my machine only have a hole big enough for a centrally positioned needle as you would use for a straight stitcher and I have to put a special switch on that will stop me trying to use a zig - zag with it and thus busting the needle. Perhaps yours is similar?