printing settings for shell

[HansLucifer]

Hi Bjoern: I may be asking this question in the wrong place, but could you please provide some guidance on printer settings for the shell? Your instructable suggests printing upside down, but I'm having a hard time finding a position that has enough points of contact to adhere to the print bed for the entire print, particularly with all the pressure put on the edges as it prints higher layers, I note in the picutre you are using a pretty wide brim, and I've tried increasing mine to 15, with three smallish contact points, but that has not been enough for me to get a successful print. Any guidance you can offer would be appreciated.
Thanks, and thanks for the cool project!