UIM F2: first metal 3D-printed propellers run in a world title round
The newsroomUpdated on October 21, 20263 minUIM F2 powerboating: two 3D-printed stainless steel propellers ran at Peso da Régua, described by their maker as a first in a world championship.
Key point
Two five-bladed 3D-printed stainless steel propellers ran in free practice of the UIM F2 World Championship at Peso da Régua, completing more than 60 laps.
Two five-bladed stainless steel propellers made by metal 3D printing ran in September during free practice at the Peso da Régua round of the UIM F2 World Championship in powerboating. According to Powerboat News, reporting on 20 October 2026, they are, in their maker's words, the first metal 3D-printed propellers to be run in a world championship.
Who is behind it
The propellers were produced by Steel Developments, the company of Dave Harwood, together with Caleb Jelf, son of circuit racer Owen Jelf. He studies Mechanical Engineering at Imperial College London and took a year out to work in Brackley for the Mercedes-AMG PETRONAS F1 Team. He first raised the idea with Harwood in 2024, when metal printing was still largely a research subject.
A first trial to prove the material
The two propellers ran on the boats of Owen Jelf and Ian Blacker and completed more than 60 laps between them. They were built to test the strength of the material, not to win races. After the first runs, Caleb Jelf says a lap time came within five tenths of the fastest propeller of that session.
Over two years he settled on the blade profile using plastic models, while studying the elastic properties, strength and fatigue of parts made with this process.
The process: direct metal laser sintering
DMLS builds a solid part from metal powder, one layer at a time, in a sealed chamber filled with an inert gas such as argon. A laser melts the powder where it strikes. A propeller does not come out ready to race: it is built on supports, heat treated to relieve stresses, then the supports are cut away and the surface is polished. The appeal is geometry, since the process can make shapes that would be difficult or uneconomic by casting or machining. The challenge is proving the part is strong enough, especially against salt water and repeated flexing.
What comes next
The project plans to vary pitch, aspect ratio and diameter using a mathematical model. The team holds a large dataset of competitive propellers on the OptiMax 200XS engine and is now focusing on propellers for the new APX250 engine, to compare its models with reality.
Key points
- First announced use of metal 3D-printed propellers in a world championship.
- More than 60 laps in free practice at Peso da Régua.
- Aim: strength first, speed second.
- Next step: propellers for the APX250 engine.
Frequently asked questions
What is new in UIM F2?
Two five-bladed 3D-printed stainless steel propellers ran in free practice at Peso da Régua, presented as the first of their kind in a world championship.
Which technique was used?
Direct metal laser sintering (DMLS): a laser melts metal powder layer by layer in a chamber filled with inert gas.
Were these propellers built to win?
No. They were built to test the strength of the material, although one lap time came within five tenths of the fastest propeller of the session.
Sources
Written by the Karrazmotorsport newsroom, proofread before publication. For settings, always refer to your vehicle's manual. Our charter.
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