This assumption is an overgeneralization. The robustness of 3D printing starts with the careful selection of the material. A blade disc made of high-impact polymers such as ASA can also withstand high loads, such as contact with solid objects, and still exhibit adequate impact resistance. The rotational speed of approximately 3000 revolutions per minute leads to
sudden obstacles to significant forces that are proportional to the mass of the rotating components, so it is crucial to choose the right material to absorb these forces. In particular, impact strength is an important property for materials used in outdoor applications such as mower decks. ASA is known for its good impact resistance, even at low temperatures. Compared to other plastics such as PLA, PETG and ABS, ASA offers the following advantages in terms of

impact resistance:

These properties make ASA a preferred material for applications that require high impact resistance, such as in the automotive industry, in construction or sports equipment that is exposed to frequent knocks and bumps. ASA's ability to maintain its integrity and performance under these conditions makes it an excellent choice for outdoor use.

Innovative design possibilities through 3D printing:

3D printing is revolutionizing manufacturing technology through its ability to create complex structures
that would not be possible with traditional methods such as injection molding. A significant advantage of this technology is the possibility, through targeted design and the use of finite element methods (FEM), to realize highly stable structures while saving on materials and weight.

Material economy and structural integrity:

An illustrative example of the principle of material economy is the comparison between a I-beam and a solid rectangular beam. The I-beam, known in the construction industry for its high flexural rigidity and load-bearing capacity, uses the material more efficiently by concentrating the mass where it contributes most to the load-bearing capacity – far from
from the neutral fiber. This principle can be transferred to 3D printing, where the integration of cavities and specific wall thicknesses can optimize the mechanical properties.

FEM analysis for optimization:

FEM analysis supports this process by simulating the load-bearing capacity and behavior of the structures under load conditions in order to adapt the design accordingly.This results in components that offer high strength and stability at a reduced weight. The ability to use cavities in a targeted manner makes it possible to create lightweight yet highly stable structures that are suitable for demanding applications.

Summary of the advantages:

In summary, 3D printing offers the advantage over injection molding that it
integration of cavities and the application of FEM analyses, high structural stability with optimized material use. This leads to lightweight but extremely resilient components that are designed for demanding applications. 3D printing uses the principle of material economy, similar to an I-beam, to achieve higher resilience with less material.

Rigid blades pose risks, especially for low material thicknesses (under 0.5 mm). They can break on contact with solid objects and act as dangerous projectiles. The direct power transmission to the drive and bearing on impact can cause damage and increased wear, which shortens the lifespan of the mowing robot. In contrast, pivoting blades
reduce the impact forces and are better suited to most lawns.

Multiple blades improve the cutting pattern and mulching effect as they cut the lawn more finely. The load is distributed over more blades, which extends their service life. Physically, the arrangement of the blades at the edge of the mower disc increases the moment of inertia, resulting in a more stable rotational movement and less interference. For dense lawns or deep cuts, a higher number of blades may be necessary to ensure a uniform cutting pattern.