Conceptual design of a swinging type brush cutter with ergonomic considerations for enhanced field efficiency

Introduction

Agriculture plays a crucial role in the Indian economy, making a notable contribution to GDP and offering jobs to almost half of the population. Although it is a top worldwide producer of key crops, the sector encounters issues like low productivity, divided landholdings, and a shortage of labor. In India, the typical farm size is approximately 1.16 ha, with nearly 85% of farms categorized as small and marginal, which restricts the implementation of advanced technologies (Mehta et al., 2016) [1] . Moreover, the decreasing role of human and animal labor has heightened dependence on machinery to guarantee prompt and effective agricultural activities. Nonetheless, the uptake of mechanization is still limited by expensive costs, restricted access to financing, and a deficiency in technical knowledge (Anonymous, 2020) [2] . This requires the creation of cost-effective and efficient agricultural equipment. Brush cutters are crucial for managing vegetation and preparing land, but traditional designs frequently lead to operator fatigue and have efficiency constraints. Thus, this research aims to create an advanced brush cutter system to boost efficiency, lessen user fatigue, and promote sustainable agricultural mechanization.

To address the limitations of conventional brush cutters, this study aims to design a swinging-type brush cutter that enhances field efficiency and reduces operator fatigue Material and Methods

This section outlines the materials and methods used for the conceptual design of the swingingtype brush cutter. The design relies on analytical calculations, field data, and recognized engineering principles. It encompasses evaluating grass characteristics, creating design equations, and integrating ergonomic factors to improve operator comfort and effectiveness.

Grass parameters assessment

An evaluation in agricultural regions close to Akola was carried out to record essential physical traits of prevalent grass and weed species affecting cutting machine design. Measurements were taken for five species, including plant height, stem diameter, stem characteristics, leaf dimensions, root type, biomass density, and cutting resistance: Cynodon dactylon, Saccharum spontaneum, Imperata cylindrica, Pennisetum purpureum, and Parthenium hysterophorus. A design shear energy of 3.9 mJ/mm² (Nandish et al., 2019) [3] was utilized for calculations of power and force, employing an average stem diameter of 3 mm as a typical reference for frequently found species such as Doob and Congress grass. resulting in 10 mm crank pin diameter and 5 mm slider thickness. The frame was selected based on section modulus criteria Z = M/σ, ensuring adequate strength.

Ergonomic consideration for the handle

The handle acts as the main user interface, and poor design may elevate musculoskeletal strain (Bo Li and Shusen Li, 2016; Jadhav et al., 2025) [5,6] . Consequently, the ergonomic handle was developed utilizing anthropometric information from BIS IS 9621:1980, which encompasses the 5th to 95th percentile of Indian agricultural labourers. The handle underwent structural verification for a steering moment of 20 Nm, leading to a required force of 100 N. For a hollow steel pipe (OD 35 mm, ID 31 mm), the bending stress was determined to be 3.24 MPa, significantly under the yield strength of mild steel, providing a strong safety margin. The handle height can be adjusted between 950 and 1050 mm to suit various users (BIS, 1980) [8] .

The design reduces operator vibrations by isolating engine vibrations via the wheeled chassis, with further damping from rubber mounts at the engine base, enhancing operator comfort (Bo Li and Shusen Li, 2016; Jadhav et al., 2025) [5,6]

Key Design Features and Advantages

The suggested swinging-style brush cutter will offer a 90 cm cutting width with each swing, removing the need for manual side-to-side movement and enhancing field coverage. The Whitworth quick return mechanism (2:1 ratio) will improve cutting efficiency, while the cart-mounted design will lessen operator fatigue by shifting the machine's weight to the wheels. The system will feature dual-mode functionality (swinging and conventional) along with replaceable blades for various types of vegetation. The combination of engine and battery in the hybrid setup will guarantee uninterrupted function, while the height adjustment feature will allow for accurate cutting regulation.

Design Limitations

The suggested machine will exhibit greater weight and mechanical intricacy than standard brush cutters, potentially impacting portability and necessitating frequent upkeep. Its capability might be restricted on steep or irregular surfaces. The initial production expense is projected to be greater; nevertheless, it is expected that operational efficiency will offset this. The battery will offer restricted support for the swinging mechanism, requiring occasional charging or replacement.

Conclusion

The conceptual design of the swinging-type brush cutter will focus on enhancing operational efficiency, ergonomics, and area coverage. The design aims to meet a cutting power requirement of around 41.32 W, with suitable dimensions for the shaft, crank, and structural elements to guarantee safe operation. The system will employ a 2:1 quick-return mechanism for effective cutting across a 90 cm width. Additional research will be necessary to confirm the machine's performance via field assessments, encompassing factors like field capacity, cutting efficiency, energy usage, and ergonomic functionality.

Acknowledgement

AcknowledgementThe author will acknowledge the guidance of the advisory committee and the support provided by the Department of Farm Power and Machinery Engineering, Dr. PDKV, Akola.

References

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