I want to be able to change the spiral in the direction of its height, so that it makes continuous spirals in the z direction. So, I want to be able to make a change radially and longitudinally. Is there a way to do this with a spiral, not a helix?
This is a possible work around as with most things.
Use a surface sweep and make a vertical line on the Front Plane and a horizontal line on the Top or Right Plane. Then use the surface sweep and one of the options will be to "twist along path". Then just adjust the parameters to get what you are looking for. Once you have the swept surface then you can start a 3D sketch and convert entities of the edge of the surface.