This is my 3rd helmet for the dummy 13 bug I got bit by :)

I tried to make it a bit more visually interesting with the geometry at the sides, and it is pushing the 0.4 nozzle I think.

You have to make sure the extraction/wall width is 0.40 for all of them to make the helmet slice properly. I have built it into the profile, but just in case you change it.

I had no need for a brim or supports, but I did also clean my buildplate with mild dishwash soap quite thuroughly to make sure it worked.