On the SINGER 319K sewing machine, if you move the needle positioning lever, the needle column moves manually to the left, center and right. But when I activate the zig zag stitch, the mechanics threaten to get heavy as if it were going to move the needle in the balance for the zig zag or decorative stitches that I have selected, but the needle column stays still and does not move with the motor moving the needle. machine. But she sews straight normally and perfectly.