def make_helix(aa, axis_distance, z_shift, phi, splay, off_plane):
        """Builds a helix for a given set of parameters."""
        start = numpy.array([axis_distance, 0 + z_shift, 0])
        end = numpy.array([axis_distance, (aa * 1.52) + z_shift, 0])
        mid = (start + end) / 2

        helix = Helix.from_start_and_end(start, end, aa=aa)
        helix.rotate(splay, (0, 0, 1), mid)
        helix.rotate(off_plane, (1, 0, 0), mid)
        helix.rotate(phi, helix.axis.unit_tangent, helix.helix_start)
        return helix
Builds a helix for a given set of parameters.