actually I tried both but got frustrated with the slicer. You can import open meshes into cura as long as they can be sliced horizontally. Though cura does’t produce very good vase /spiral mode toolpaths, I am trying to make my own.
I know nothing about “vase mode” but it looks to me like one issue is that the seams are not aligned. I fixed that by moving the seam on all lines to the first point where they cross each other in top view.
The second issue is that alternate zig-zag curves are out of phase when spiraled. I wonder if it would work better to create a spiral from the circular “base curves” before implementing the zig-zag pattern?
Make a cylinder 20 units high and 20 units radius:
This cylinder has no thickness but it can still be 3D printed using Vase Mode. To do this you run the Rhino exported geometry (STL format) through a slicer program that produces the toolpath for the 3D printer.
The slicer, in Vase Mode, produces this toolpath for the printer:
Note that the path shown in the image will be printed from melted plastic that is extruded through a 0.4 mm diameter nozzle, so it is very thin and quite fragile. I would never print something like this because of this fragility.
The concept behind vase mode is that it eliminates any surface imperfections caused by starting/stopping a print loop.
For a “real” print it is necessary to give the printed geometry some 3D thickness. This is easy to do for a cylinder, but can get quite tricky for more complex shapes. Here is the cylinder with 1 unit thick walls:
And here is the resulting toolpath that the slicer creates:
Note that the cylinder is now comprised of many individual horizontal layers that are 3 loops thick. This is enough to give the print reasonable strength (although I typically make my prints a bit thicker.)
More importantly, there is a seam (vertical in this example) where each individual loop starts and stops. These start/stop points create slight imperfection in the print’s outside surface. Dealing with these is an issue of it’s own.
Konrad: Maybe what you should do is create a single, continuous curve that has the shape you want, Pipe it, and print that.
The problem is that the dot pattern isn’t totaly regular but takes the last layer into account to optimize the distribution. Because of that dividing a spiral purely based on distance to the last point will result in “running” columns as seen here: