How to model such thing http://cdn.indulgy.com/SJ/XJ/Yu/260153315944332662mnTq48rPc.jpg in SolidEdge / SolidWorks / Inventor?
Create a helical sweep of the profile that you want and then go back and add the detail that you need. Hope this helps
Sorry, but I don't think that is so simple... try and show me that works :)
It kind of is, as I see it you need to make it as a loft with multiple profiles ... it will need a lot of work and tweaking, if you have the polygonal model then take pictures of the cross-sections to help.
Brian is correct you have to start with a helical swept cut to get the initial profile. In SolidWorks, there is no easy way to create a pattern to create those steps. You would have to create them individually after creating the initial cut. I would create a boundary surface for the steps with two splines and then use a thickened cut to cut out each step.
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