World’s first 3D-printed remote control aircraft with a jet turbine takes flight, aims for Mach 0.8 to beat world record for fastest model aircraft
The Kingchaser, a 3D-printed jet-powered remote-controlled aircraft made out of PETG, PPS-CF, carbon-fiber rods, and aluminum, aims to take the world speed record after its maiden flight, with a target of Mach 0.8. The Mach Initiative aims to break the current Guinness World Record held for 9 years by German pilot Neils Herbrich. The team of graduates from the University of Bath has posted their maiden flight of the Kingfisher to YouTube.
The team started out with their first miniature prototype, the Kinglet, made out of PETG, PET-CF, and some PLA. It didn't use a jet turbine yet, opting instead for an EDF (Electric Ducted Fan) as a safe and low-cost way to iterate. The Kinglet used a modular design to rapidly prototype the aircraft in sections and replace any broken parts without needing a whole new body.
Once the Kinglet had reached a level of performance the team was happy with, they moved on to the Kingfisher, measuring just under a meter, propelled by the Jetcat P60, a miniature jet turbine engine capable of 63 N m of thrust, reaching a top speed of 205 mph (330 km/h). The Mach Initiative stated that this engine is not powerful enough, nor is it intended to break the record, aiming solely to achieve flight with a jet engine. The team had to make some major design changes from the Kinglet due to the larger size and much higher forces the aircraft would have to endure. The Kingfisher is still also made mainly out of PETG, with the housing of the engine out of annealed PET-CF. The engine is held in place by aluminum hardware, with the rest of the aircraft being reinforced by an aluminum skeleton.
The engineers initially intended the Kingfisher MK2 to be the aircraft that would house a 150Nm jet engine to break the record, attempting to hit 614 mph (988 km/h), leaving the world's fastest electric drone (434 mph) in the dust. However, they decided to make a new aircraft that was 20% larger than the Kingfisher and called it the Kingchaser, with significant changes to the design.
The 20 lb (9 kg) Kingchaser still uses mostly PETG for its external construction, but instead of annealed PET-CF for the engine housing, they switched to PPS-CF, as annealing the larger housing caused warping, possibly due to uneven heating. The PPS-CF is also skinned with a few layers of carbon fiber, further reinforced with aluminum and steel to mount the engine. They also put titanium exhaust sheets and aluminum tape to shield the print from the engine's heat. The aluminum skeleton running through the PETG body has also been replaced with carbon fiber rods instead to save more weight and use fewer custom-CNC machined parts.
For the electronics, they have a dedicated flight control and avionics member who works on the electronics. The Kingchaser has a fully instrumented avionics system to collect as much telemetry from the aircraft as possible; it is also equipped with an FPV system for better piloting at speed. To control the aircraft, 70 kg-cm (5.06 ft-lbs) high-torque servos were used on the elevons, as it would take a considerable amount of force to move those flaps at speed.
There is currently no announcement of when the record attempt will be made, but you can keep up with The Mach Initiative's entertaining build logs on their YouTube channel.