Did you check to see that the needle position was set for straight stitching? Does this machine have a straight stitch throat plate as well as a zig-zag throat plate? If the machine was set to do a fine zig-zag it would definately rub on the straight stitch plate. Was a cam left in and now is causing trouble? The needle should definately not be scraping on the throat plate. Good luck trouble shooting this one. (Check the instruction book too!)