I guess removing the hole in the top removes a trip through CGAL and the circle coordinates remain exactly equal. However I can't understand where the extra circle vertices come from as they are not numerically close to the real vertices.

> See if you get better results with this: > > extra_scale = 100; // increase if needed > step = 0.0035; > scale = 100*extra_scale; > > top = [for(x = [0:step:1]) scale * [x, > 0.12 * naca_thickness(x)]]; > > scale(1/extra_scale ) polygon(points=top); > > scale(1/extra_scale ) %for(p = top) translate([p[0], p[1], 0])

I'm trying to put the top point for the r2 pie wedge on the y axis On Sun, Sep 18, 2016 at 12:40 PM, runsun wrote: > DanS wrote > > I'm trying to move what you did so the bottom is lying on the x > > axis and the top is on the y axis.

When you do F6 and > get > > the simple output: > > > > Top level object is a 3D object: > > > > Facets: 6 > > > > > > CGAL has not been used at all.

The result is that they have slightly different roof angles and/or the top roof is slightly offset +Z from the other. This leads to the same effect as with the cubes above. Carsten Arnholm