It is pretty well documented how to make a single start thread with the Helix/Spiral curve and a sweeped cut. I have done it a time and time again but I'm not sure how to creating a double or a triple start thread. I'm hoping someone will be able to help me with this.  Would it be as simple as creating two helix curves 180 apart from each other and make two sweep cuts?

Anyone have any suggestions? Thanks.