Because the boards can't tolerate too much heat, modern, computerized machines CANNOT be all metal like the glorious oldies (have 'em, love 'em, use 'em!). But Berninas have a LOT of metal, a very rigid frame. The lighest-the Activas and 3 series-are still about 18 lbs each. Janome uses a metal skeleton to achieve rigidity with less weight. The plastics are not the same as the cheaper machines.