A method for preparing encapsulated red phosphorus is disclosed. In at least some embodiments, the vehicles include frames that are wider near the front and rear sections of the vehicles than within the mid-sections of the vehicles. The viscosity modifier is then removed from the build material preferably by evaporation, and the layer is selectively solidified to form the three-dimensional object. In such a state, even if the inertial mass attempts to displace toward the lock activation direction, the restriction weight interferes with the inertial mass and restricts displacement of the inertial mass toward the lock activation direction.