all the tips azwendg gave you are perfect, set the bobbin first (after making sure the bobbin is going clockwise (90% of machines...but check your book)... the drop test is the perfect thing... it should slowly move downward with no more than a tiny encouragement of jiggling the thread just a tiny bit... now how to decide if it is balanced? take threads out from under the foot. put foot down. pull both threads till they are the same length, clipping to make sure...they must be relaxed. now pull both threads together and then release. if one of them curls madly and is now way longer, (usually the top) then adjust till they are closer to the same length. now sew and see if the top thread and bottom thread appear on the opposite sides in the same size. different colored thread to the fabric scrap helps to see better. just persist. it will work if both threads are threaded correctly... it just takes a bit of fiddling. people get the threading wrong all the time, be sure to check...
Last edited by deemail; 12-13-2011 at 11:56 AM.