This 3 inch frameset is part of Kevin's Design on RotorBuilds/thingiverse. It is printed in Onyx and reinforced with continuous carbon fiber for best weight to stiffness ration while still maintaining flexibility to withstand the hardest of crashes. The kit includes the main frame, top plate, cam and a motor mount.
Onyx is a nylon infused with chopped carbon fibers. The Markforged Mark Two Enterprise on which this part is manufactured is one of the best printers in the industry, with unrivalled print quality and precision.
The parts can also be found on Kevin's thingiverse. This product is a cooperation of Kevin and me, Kevin also gets a kickback from all purchases.