Easy to fly: new polymers will reduce the cost of Russian drones by almost a quarter

Russian engineers have developed a range of lightweight two-stroke internal combustion engines for drones. Some of the metal parts in them have been replaced with high-temperature polymer composites, which reduces the amount of aluminum machining and speeds up production. According to experts, the use of new materials will reduce the cost of UAVs by an average of 20-25%. At the same time, before serial use, the engines will have to confirm their reliability when operating in different climatic conditions and under prolonged loads, experts noted.

From metal to composites

Russia has found a way to significantly reduce the cost of UAV production. The development is based on the partial replacement of metal parts with polymer composites. Some of the components can be made by injection molding and layer-by-layer deposition (FDM printing), while the most loaded elements are still made of metal by stamping. This approach reduces labor intensity and allows you to quickly adapt the power plant to various designs of drones.

Initially, engineers tried to completely abandon metal, but it turned out that this was impractical for a number of parts. As a result, the developers settled on a combined design. Polymer materials were tested for thermal and vibration loads: individual composites withstood heating cycles from 160 to 300 degrees.

The project developed in stages. In 2023, research work was carried out to create a lightweight engine with polymer components, and in 2024, development work began. During this time, the team has produced 32 variants of the power plant and conducted more than 24 tests. The engines were subjected to detonation, thermal and vibration loads, as well as flight and resource checks. In one experiment, the engine was dropped from a height of up to 100 m, after which it worked on the stand for four hours.

— The share of the cost of the engine in the UAV is on average 30-40%. The new production technology will reduce the cost of the engine by more than half to less than 15% of the total cost of the drone, which will potentially reduce the total cost of UAV production by about 15-25%, the authors of the technology reported.

The second part of the development was its own electronic fuel injection system for two-stroke engines. It integrates with the flight controller and, according to the developers, allows you to save from 10% to 40% of fuel, depending on the operating mode. The system also ensures a stable start and makes it possible to repeatedly turn off and start the engine directly during flight. Electronics take into account changes in pressure, humidity, and temperature.

By 2026, the project has reached a high level of technological readiness — TRL 8, which means that the device has been tested in real conditions. 5, 12, and 24 hp engines have been developed, as well as proprietary ignition, electric starter, and electronic injection systems.

The next stage should be mass production. The developers expect to produce tens of thousands of engines per month. The project was included in the top 100 of the platform "Strong Ideas for Modern Times" in the track of the National Technology Initiative (NTI).

— It is important to note that the technology has great potential for dual use. Scientific work continues. At the same time, research is underway to create a hybrid power plant based on one of our engines, the power of which will allow the engines of the cargo copter to operate in full functional mode," said developer German Stashevsky.

According to Konstantin Okunev, senior partner of the project, the development may be in demand when scaling up the production of drones. He noted the combination of industrial applicability of the technology and cost reduction of the power plant.

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Such UAVs are characterized by long-term operation and unpretentiousness to weather conditions.

Fuel and mass savings

The transition from deep machining of aluminum to casting and additive manufacturing may be one of the ways to accelerate the production of engines for drones, experts say. At the same time, the rejection of the complete substitution of metal with polymers makes it possible to preserve traditional materials where the main load falls on the parts.

— This is a mature engineering solution that meets the real demand of the market. The engine remains one of the most expensive and time—consuming components of a drone, and it is often what holds back the growth of serial production," said Artyom Bogatyrev, market expert at Aeronet Research Institute.

According to him, partial replacement of metal with polymers can be a rational compromise between cost reduction and strength requirements. The electronic injection system is of particular importance: for two-stroke engines, it allows for increased efficiency and stability of operation under changing external conditions.

Reducing the weight and cost of the power plant in the future may affect not only the price of the drone itself. The lighter vehicle is capable of either carrying an additional payload, or using the released mass to increase fuel reserves and flight range.

— If it is possible to reduce the total weight of the product and even reduce its cost, this means that the device can become more widespread. In addition, it will allow carrying more payloads or increase the flight range, which will also increase the value of such devices," said Nikita Kulikov, Director General of the NGO PravoRobotov, PhD in Law.

At the same time, cheaper components by themselves do not guarantee a proportional reduction in the cost of the entire drone, experts say. The final effect will depend on the resource of polymer parts, the stability of their characteristics during long-term operation, and the cost of scaling production.

For serial use, it will be necessary to confirm the reliability of the engines in different climatic conditions and under prolonged loads. Therefore, the stated reduction in the share of the engine in the cost of the UAV should still be considered as a target indicator of the developers, and not as a guaranteed reduction in the price of finished devices, Nikita Kulikov summarized.