A system that delivers window or door components to an assembly station where multiple components are assembled to form a multi-sided window or door frame or sash. A preparation station in proximity to the assembly station includes an alignment fixture for bringing multiple frame or sash components into alignment while a preceding frame or sash is being assembled at the assembly station. A conveyor moves aligned components of a next subsequent frame or sash to the assembly station while maintaining the alignment of said window components for clamping at the assembly station prior to assembly. One system is used to assemble vinyl door or window components by welding them together.