Graduates of the University of Bath, working as The Mach Initiative, have flown a mostly PETG printed model aircraft powered by a miniature jet turbine. They are now building a larger airframe, the Kingchaser, aimed at a Mach 0.8 model aircraft speed record. No date for the record attempt has been announced.
Key facts
Kingchaser is 20 percent larger than Kingfisher and weighs about 9 kg
Engine housing moved from annealed PET-CF to PPS-CF after warping
Record target is Mach 0.8, about 988 km/h
No date for the record attempt announced
Context PPS-CF is polyphenylene sulfide filled with short carbon fiber, a high-temperature engineering polymer; annealing is a heat treatment applied after printing to relieve stress and improve stability.
How did the design develop?
The team began with the Kinglet, a small prototype in PETG, PET-CF and some PLA. It used an electric ducted fan instead of a turbine, as a cheap and safe way to iterate, and its modular sections let broken parts be replaced individually.
The Kingfisher, just under a metre long, followed with a Jetcat P60 miniature turbine. The team says this engine is not meant to break the record, only to prove jet flight. Its body is mainly PETG, with the engine housing in annealed PET-CF, aluminium hardware and an aluminium skeleton.
What changes in the Kingchaser?
The Kingchaser is 20 percent larger than the Kingfisher and weighs about 9 kg. Annealing the larger engine housing caused warping, so the team switched to PPS-CF, skinned with carbon fiber layers and mounted with aluminium and steel. Titanium exhaust sheets and aluminium tape shield the print from engine heat.
Carbon fiber rods replace the aluminium skeleton to save weight and reduce CNC machined parts. It carries full telemetry avionics, an FPV system and high-torque servos on the elevons. The earlier plan for the second Kingfisher version, with a stronger engine, was dropped in favour of this new airframe.
What it means
A hobby and student project, but it shows practical limits of polymer extrusion parts near a hot engine: annealing larger PET-CF parts warped, and heat shielding plus hybrid reinforcement were needed. For manufacturers, the lesson is that material choice, post-processing and part size interact, and that modular design reduces repair cost during iteration. No qualification data is involved.
Frequently asked questions
What materials is the Kingchaser made from?
Mostly PETG for the exterior, PPS-CF for the engine housing, plus carbon fiber rods, aluminium, steel and titanium exhaust sheets.
Why was PPS-CF chosen?
Annealing the larger PET-CF engine housing caused warping, possibly from uneven heating, so the team switched material.