Workflow Suggestions Please

[Jim57]

SU model of where I"m at nowI'm trying to model this twisted piece. First, it's a helix that increases then decreases in diameter. Second, the profile on the helix is a large convex curve joined to a smaller concave valley. The diameters of them increase and decrease with the overall diameter. I'm attaching a rendering of a badly drawn version.

I first modeled it with K tools, spiral around z axis. It came out misshapen and was very difficult and time consuming to fix. Now I'm working with Loxodrome ruby (for the initial helix on a sphere) modified by FredoScale to taper different sections. The real stumbling block has been EEby tools— I keep getting crashes after I extrude a circle by two parallel helical rails. I've reduced the circle to a square and reduced the length of the helixes and it's still no good, SU still crashes after computing faces but before displaying them.

I then tried Pipe Along Path, hoping with FredoScale I could section the helix and open it up to 20 or so smaller tapers. Looks like by that method I'd have to taper every section of the pipe (i.e. every facet of the helix), more like 150.

Can anyone suggest a faster or more appropriate way?

Thanks,

Jim

[Jim57]

Here's a picture of my first attempt. I'm referring to the carved worm between the top and bottom turnings. The extra lines above and below them I left in for editing purposes.

Thanks in advance,

Jim

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