okay i use c_scan and it works! but now i have another problem. the box flys to fast..even by a force of 5. so i set a mass for the box. 50 is a good value because the box behaves as i want.but now the box falls through the level. i tried different values. if i use 9 or less the box lands correctly on the ground. if mass is 10 or more, the box falls through the ground...is this a bug???