A thread about threads

 From:  wibble
Hi, folks!

How would I make a thread in MoI? That is - a thead on a bottle or a sparkplug?. I'm guessing that it involves first making the thread with a curve and then using the Sweep function to solidfy it. But how the heck do I spiral a curve upwards? :)

p.s Great interface, Michael! ...and awesome fillets! :)