My grandson bought a singer sewing machine at a thrift store so he could make his own backpacking stuff. He brought it out for me to show him how to thread it and to see if it worked( I would have found that out before I bought it) . It worked but the feed dogs moved up and down but not forward and backwards. It is a metal machine. "Stylist 834" I think it would be worth getting fixed . Do any of you ladies know anything about this machine? what could make the feed dogs not work?