Print with no top and 0.4mm wall for a nice vase. As you can see from the photos, it prints out just great on my Ultimaker.

I created this by lofting the Nautilus Gear DXF around a helix in Bonzai3D.

1) CCWNGV01.stl - the vase with a counter clockwise twist.
2) CCWNGV01.stl - the Bonzai3D file for the vase.
3) NGORIGINAL-FIXED.dxf - a tidied up version of the original Nautilus Gear DXF. This has nice sinusoidal teeth. My original Nautilus Gear vases used a simplified triangular tooth form.
4) NGORIGINAL-FIXED.bnz - a tidied up version of the original Nautilus Gear DXF in Bonzai3D format.

I have not been able to import the NGORIGINAL-FIXED.dxf file into OpenSCAD - I don't know why - there seems to be something wrong with the format. Also, as you can see, it doesn't seem to render on Thingiverse. It works OK with Bonzai3D though. I have put it up here anyway in case someone can work it out.

In case you are thinking it (I know I did!) if you print the clockwise form of the vase it will NOT work as a gear against the counter clockwise form. This is because the slope of the gears changes as a function of the distance from the centre of the logarithmic spiral. I wonder if this could be fixed...