In your opinion, what is the best way to print a helmet in one piece (orientation, support, etc)? I'm trying to avoid having to weld or glue multiple pieces.
Assuming that we are talking about the FDM printers, other people may have different opinions but we always print helmets upside down (top touching the bed) and just sand it after printing. We would position the helmet a little bit above the ground so it floats and gets supported by structures. This way you can make sure that the top part contacting the printer's bed does not get flat. We mostly do this to save filaments/materials. But if the helmet has a lot of details like the Black Panther helmet (Free download at https://www.do3d.com/forum/free-3d-print-model-list) and saving the materials is not your primary concern, we would orient it in the way that those details you want to retain do not get supported heavily by the structures. Hope this answers your question.
Assuming that we are talking about the FDM printers, other people may have different opinions but we always print helmets upside down (top touching the bed) and just sand it after printing. We would position the helmet a little bit above the ground so it floats and gets supported by structures. This way you can make sure that the top part contacting the printer's bed does not get flat. We mostly do this to save filaments/materials. But if the helmet has a lot of details like the Black Panther helmet (Free download at https://www.do3d.com/forum/free-3d-print-model-list) and saving the materials is not your primary concern, we would orient it in the way that those details you want to retain do not get supported heavily by the structures. Hope this answers your question.