Mach figures
The team called The Mach Initiative is preparing for a speed record with Kingchaser, a jet-powered unmanned aircraft produced largely through 3D printing. The design goal is transonic Mach 0.8, equivalent to approximately 990 km/h. Even if this speed is only approached, the quadcopter — at 626 km/h the world’s fastest drone — will be left behind.
PETG’s new steps
The orange sections of the fuselage were printed from PETG; carbon fiber rods and an aluminum frame provide strength. The black part around the motor is made of PPS-CF material wrapped in carbon fiber to withstand heat. The team had previously flown the small Kingfisher model, made of PLA, which earned the title of the first 3D-printed jet. The reason for the switch to PETG is the aerodynamic heating expected at this speed.
Open questions
Since surface friction is dominant in this speed regime, the skin was sanded smooth. The motor produces 300 N (68 lbf) of thrust. Details about the record attempt are explained in the team’s video.