Modeling Conveyor Screws (AKA, flight screws, spiral ...
See thread559-139592, "Flat pattern of a screw conveyor type flight?". Do a search on this forum for "helix" or "spiral", even screw threads. What you want would basically be modeled similarly. Not sure about an add-in, but after creating a model, make a design table so you can easily modify the perimeters of it. Flores SW06 SP3.0