I have a model for a helmet, which is not perfectly flat on the bottom. It arches upwards slightly, and this causes all sorts of trouble for attempting to print it. It seems that no matter what I do, I can't get support under the rim of the helmet, either automatic or manual, and attempting to print without it doesn't work because the distance is just too far and the printer ends up printing a bunch of spaghetti in the air.
Here's an image of what the slicer generates. This is a side view in orthographic projection.
As you can see, there's a very small raft area at the very front of the model, where it touches the build plate, and nothing else anywhere. I'm just about at my wits' end here, because no matter what I do, I can't generate anything anywhere under the back of the model!
Can someone please explain what I'm doing wrong and how to fix this?