Thanthai Periyar EV Ramasamy Government Polytechnic College Vellore, Tamil Nadu
This work describes the conceptualization, construction, and experimental assessment of an economical mini belt grinding machine designed for accurate material removal with minimized energy usage. The developed unit operates using a single-phase electric motor that drives a continuous abrasive belt through a refined drive and idler wheel arrangement, ensuring consistent belt alignment and controlled grinding force. Mechanical robustness and reduced vibration are achieved by employing a rigid mild steel support structure, properly balanced rotating components, and low-resistance rolling bearings to ensure smooth functioning. An adjustable belt tightening mechanism together with a precisely finished platen surface contributes to improved geometrical accuracy and superior surface characteristics for different workpiece materials. Performance trials carried out on mild steel, aluminum, polymeric materials, and wood indicate stable stock removal capability and improved surface texture under various abrasive grit specifications. Energy performance comparison reveals lower electrical consumption than traditional bench-type grinding machines while sustaining effective machining efficiency. Due to its compact layout, affordable manufacturing cost, simple maintenance requirements, and scope for future enhancements such as variable speed regulation and automation features, the proposed system is well suited for small manufacturing enterprises, training institutions, and distributed workshop applications.
The mini belt grinder is a compact and multifunctional machining device designed for grinding, polishing, sharpening, and surface finishing applications. Its development addresses the increasing demand for space-efficient and economical grinding solutions in small workshops and decentralized manufacturing units. The system operates through a continuously rotating abrasive belt driven by an electric motor via a drive and idler wheel arrangement. Unlike conventional rigid grinding wheels, the flexible abrasive belt enables uniform material removal and improved surface integrity. The structural frame, typically fabricated from mild steel, ensures mechanical strength, rigidity, and vibration resistance during operation. A belt tensioning and tracking mechanism maintains proper alignment and stable motion throughout the grinding process.
2. System Architecture and Component Specification of the Mini Belt Grinder
This section presents the structural configuration, functional elements, and technical specifications of the developed mini belt grinder. The machine is designed to achieve efficient material removal, operational stability, and ease of maintenance through a carefully selected combination of mechanical and electrical components.
2.1 Prime Mover: Electric Motor
A 0.5 HP, 1440 rpm single-phase AC motor is employed as the primary power source of the system. The motor converts electrical energy into rotational mechanical energy required to drive the abrasive belt. Operating typically at 230 V and 50 Hz, the selected rating provides adequate torque for light to medium grinding tasks such as sharpening, polishing, and controlled stock removal.
2.2 Drive Wheel Assembly
The drive wheel is the principal rotating component responsible for transmitting motion from the motor to the abrasive belt. It is fabricated from mild steel or aluminium depending on load requirements and weight considerations. The wheel is mounted securely on the motor shaft using a key–keyway or set screw mechanism.
2.3 Idler Wheel Mechanism
The idler wheel is a non-powered rotating element that guides and supports the belt while maintaining alignment. Materials such as nylon, plastic, mild steel, or cast iron may be used depending on load and durability requirements. The idler wheel rotates freely on rolling-element bearings to reduce friction and wear.
2.4 Belt Tensioning System
A spring-loaded tensioning mechanism incorporating a high-carbon steel tension spring and adjustment bolt is provided to maintain optimal belt tightness. The system compensates for belt elongation during operation and ensures consistent contact pressure between the belt and workpiece. Proper tension improves tracking accuracy, reduces vibration, and enhances grinding efficiency.
2.5 Abrasive Belt Unit
The abrasive belt is a continuous flexible loop consisting of a backing material (cloth or polyester), bonded abrasive grains (such as aluminium oxide or silicon carbide), and adhesive bonding agents. It operates over the drive and idler wheels at belt speeds typically ranging between 10–25 m/s. Material removal occurs when the workpiece is pressed against the moving abrasive surface.
2.6 Platen Support Plate
A rigid platen plate fabricated from mild steel flat stock is positioned behind the abrasive belt to provide a stable backing surface. This arrangement prevents belt deflection and enables flat, accurate grinding. In some configurations, a wear-resistant overlay may be added to extend service life. The platen ensures uniform material removal and improved dimensional precision.
2.7 Adjustable Tool Rest
The tool rest, constructed from mild steel angle or flat sections, supports and positions the workpiece during grinding operations. It is adjustable to accommodate varying workpiece dimensions and grinding angles. The rigid support minimizes vibration, improves operator control, and enhances safety.
2.8 Structural Frame
The structural framework forms the backbone of the machine, supporting all major components including the motor, wheels, and tensioning assembly. It is commonly fabricated from mild steel square pipes or angle sections due to their high strength, weldability, and cost-effectiveness. Alternative materials such as aluminium, stainless steel, or cast iron may be selected depending on portability, corrosion resistance, or vibration damping requirements
2.9 Bearing System
Two deep groove ball bearings (e.g., 6202 or 6203 series) are incorporated to support rotating shafts. These bearings accommodate radial and light axial loads while minimizing frictional losses. Their use enhances rotational smoothness, reduces power consumption, and increases mechanical reliability.
2.10 Electrical Control Components
The electrical system comprises a speed control switch, insulated copper wiring, and a standard power plug. The speed controller regulates motor output by adjusting supply voltage or through electronic modulation techniques. Properly rated wiring ensures safe current transmission, while the plug enables secure and detachable power connection. These components collectively ensure safe and controlled machine operation.
3. Governing Equations:
3.1 Structural (Static) Analysis
3.2 Boundary Conditions
3.2.1 Structural Analysis
Fixed support at frame base
Load applied at workpiece contact area (simulating grinding force)
Gravity included
3.2.2 Thermal Analysis
Heat generation at belt-workpiece interface:
Where:
3.2.3 Thermal Analysis
Where:
= thermal conductivity
= temperature
= volumetric heat generation
Dynamic/Modal Analysis:
Where:
[M] = mass matrix
[K] = stiffness matrix
= displacement vector
Grinding force approximation:
Where:
= shear stress of material
= contact area
ACKNOWLEDGE
I express my profound gratitude to my Departmental Head Dr. S. Dhanalakshmi and Project mentor Ms. R. Uma Mythili. M.E, for their invaluable guidance, insightful suggestions, and unwavering support throughout. I also acknowledge the constructive feedback and encouragement provided by colleagues and peers, which significantly enhanced the quality of this work. Their collective contributions have been instrumental in the successful completion of this study.
REFERENCE
S. Arunachalam*, U. Gokulnath, M. Kathiravan, S. Dhanush, G. Kaviyarasu, Design Optimization of a Mini Belt Grinding Machine for High-Accuracy Lathe Tool Edge Preparation, Int. J. Sci. R. Tech., 2026, 3 (2), 222-226. https://doi.org/10.5281/zenodo.18678645
10.5281/zenodo.18678645
