translate([knifebar_x_off, knifebar_y_off-knifebar_rear_wall, 0])
cube([wall, -knifebar_y_off+wall+knifebar_rear_wall, body_h]);
// translate([knifebar_x_off, knifebar_y_off-knifebar_rear_wall, 0])
translate([knifebar_x_off, knifebar_y_off-knifebar_rear_wall, 0])
cube([wall, -knifebar_y_off+wall+knifebar_rear_wall, body_h]);
// translate([knifebar_x_off, knifebar_y_off-knifebar_rear_wall, 0])