The very impressive long range 18650 battery 3" quad from Dave_C. This frame is 18.5g and printed from PETG. It's significantly more durable than PLA and fully heat stable. It's more flexible than an ABS print but should be lighter and less brittle. PETG isn't the easiest thing to print so this is a bit different than what you might print yourself.
Optional 8.4g tray designed to hold a single 18650 battery
Note that as a printed product, it will have the print lines on the structure.
Check out Dave_C_FPV's Thingiverse page HERE for more details