Print top face down. And the back case also print with back side down so the large flat surfaces are on the print bed. do the battery crossfire support ive printed it either way up and it works fine both ways laying down, i tried printing standing up but it wasnt stable enogh and would get knocked over.
for the buttons i printed them in a genaric tpu material from ebay, nothing fancy.
the main case is printed in esun pla plus.
i printed with .6 top and bottom layer and .8 wall thickness.
top and bottom cases were aout 13 hours each then the grips and battery tray was about another 6 hours.