Posted on 20/08/2025

The weight-to-volume ratio in 3D printed parts

In the aeronautical industry, weight is synonymous with cost. A lighter aircraft consumes less fuel, increases its range, and can carry a greater payload. Reducing a single kilogram on a commercial aircraft can lead to considerable fuel savings per year. This is where the weight-to-volume ratio comes into play, an indicator that measures the effective density of a part: how much it weighs relative to its size.

Additive manufacturing allows us to tackle this challenge with solutions impossible to achieve through traditional methods. Unlike machining, which often requires solid blocks of material, 3D printing builds parts layer by layer, integrating internal cavities, lattice structures, and optimized geometries. This not only reduces weight and material consumption but also maintains—or even improves—mechanical strength.

Design Strategies for Lightweight Parts in 3D Printing

Using Infill and Hollow Structures (FDM/FFF and SLA/Resin Printing)

Source: Fabbaloo.Com.

In technologies like FDM (Fused Deposition Modeling), the secret lies in the infill percentage. A part printed with 100% infill is solid, but if we reduce this value to 20%, the interior consists of patterns like hexagons or gyroids, leaving ample air spaces. This drastically reduces weight without altering external dimensions.

In SLA (Stereolithography), parts can be designed hollow from the start, with drainage holes added to remove uncured resin. This is ideal for large components, such as sensor housings, where hollow parts that only need a robust outer wall are used.

Lattice and Cellular Structures: Complex Geometries for Printing Lighter Parts

Lattice structures—inspired by honeycombs or natural sponges—are a great ally for lightweighting. These internal meshes distribute loads efficiently, removing excess material without compromising functionality and maintaining mechanical requirements. In SLS (Selective Laser Sintering) printers, where unused powder acts as support during manufacturing, it's possible to create metal or nylon parts with intricate frameworks that would be impossible to create with a milling machine or a mold.

An emblematic example is titanium engine mounts for space rockets: using lattice structures, companies like SpaceX have managed to reduce the weight of these components by 40%, improving the thrust-to-weight ratio.

In aeronautics, Airbus uses gyroid infills in structural components of the A350, achieving savings of 30% compared to traditional parts.

Topological Optimization and Generative Design

Source: Infinitiaresearch.Com.

What if an algorithm automatically removed unnecessary material from a part? Topological optimization does precisely that: it analyzes load areas and removes everything that doesn't contribute to the strength of those key areas. The result is organic designs, reminiscent of the human skeleton and other patterns found in nature, which today can only be created through 3D printing.

Generative design, driven by artificial intelligence, goes a step further. It proposes multiple iterations of a part, optimized to minimize weight and maximize performance. Airbus applied this technique to a cabin partition, reducing its weight by 45% compared to the original design. In the automotive industry, General Motors redesigned a seat bracket using this methodology, achieving a part that was 50% lighter and 20% stronger.

High-Performance Materials: The Key to Lightweight and Strong Parts

Material selection is fundamental in weight optimization. It's not enough to redesign geometries: advanced polymers, composites, and metal alloys adapted for 3D printing complete the circle, allowing for notable improvements in the weight-to-volume ratio.

Some of these materials are available in formats compatible with different 3D printing technologies. For example, carbon fiber reinforced Nylon can be used as filament for FDM/FFF printers and also as powder for SLS sintering.

Below is a table of some of the materials that are redefining boundaries:

Material Advantages Typical Applications Printing Requirements
PEEK - Density: 1.3 g/cm³ (vs 2.7 g/cm³ for aluminum)
- Resistance up to 250°C
- Non-corrosive, flame retardant
Structural components in engines, cabins Professional FDM printers with hot-end capable of reaching 400-500°C and heated chamber (>130°C)
Ultem 9085 - Meets FST regulations (low smoke/toxicity emission)
- High strength-to-weight ratio
Air ducts, cabin supports
PEKK - Superior chemical resistance
- Sterilization compatible
Medical parts, aerospace components
(PEKK/PEEK/PEI) + Continuous Fiber - Strength comparable to aluminum
- 60% lighter weight
Critical structural components Special professional FDM printers with support for continuous fiber filament printing.
Nylon + CF - 200% increased stiffness vs standard nylon
- 40% reduced weight
Drone chassis, robotic supports Professional FDM printers, or mid-range printers with good heat retention. Reinforced nozzles.
PETG + CF - Ideal for rapid prototyping
- Low cost
Lightweight tools, functional prototypes Home FDM printers with reinforced nozzle.
Ceramic Resins - Thermal stability up to 1000°C
- Low electrical conductivity
Engine coatings, tools SLA/DLP printers with oven post-curing
Titanium (Ti6Al4V) - Optimal strength-to-weight ratio (4.5 g/cm³)
- Biocompatible
Structural brackets, turbines DMLS/SLM printers with high-power laser
Aluminum (AlSi10Mg) - Lightweight (2.7 g/cm³)
- Good thermal conductivity
Housings, antenna supports

Applications in Aeronautics: Success Stories

Structural Components in Commercial Aircraft

Airbus leads the adoption of 3D printing in critical components. In the A350 XWB, it replaced machined metal supports with titanium versions printed with cellular structures. The result: 30% less weight and the same load capacity. Furthermore, it consolidated multiple parts into a single one, eliminating heavy joints and weak points.

Engines and Propulsion Systems

The fuel injector of General Electric's LEAP engine is a milestone in optimizing parts with 3D printing. Originally composed of 20 welded parts, it was redesigned as a single 3D-printed component. This change not only reduced its weight by 25% but also quintupled its durability. In turbines, 3D printing allows for the integration of internal cooling channels, lightening blades and improving rotational efficiency.

Interiors and Drones

In cabins, materials like Ultem 9085—a high-strength polymer—have replaced metals in air ducts and panels. Boeing, for example, prints these components in Ultem, achieving 60% weight savings compared to aluminum. In military drones, nylon housings with lattice infill extend flight autonomy while maintaining structural strength.

Beyond Aeronautics: Lightweighting in Other Industries

  • Automotive: BMW uses engine mounts printed from aluminum alloy, 30% lighter than traditional ones, to improve the efficiency of their electric vehicles.

  • Energy: Wind turbine blades with lattice cores created through 3D printing reduce inertia and facilitate installation.

  • Robotics: Industrial arms with hollow structures in PEEK allow for faster movements and lower energy consumption.

Source: Facfox.Com.

Conclusion: Lightweight and Efficiency, the Future of Lightweight Parts Manufacturing.

3D printing is not just a production tool, but an opportunity to reimagine industrial design. By combining advanced materials, optimization software, and geometric freedom, companies across all sectors can create lighter, more efficient, and more sustainable parts.

In our store, you will find everything from technical filaments like Ultem 9085 to printers capable of working with metals and professional printers for composites. If you are looking to reduce the weight of your components without sacrificing performance, explore our solutions or contact our team for customized projects.

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