Engineering and Fabrication of Coffee Roasting Machine: Precision Mechanical Drive for Efficient Small-Scale Coffee Processing

Abstract

Roasting is one of the important processes in coffee processing to produce a distinctive aroma and taste that is the main attraction for consumers. However, the roasting process, which is still widely performed manually, has limitations in efficiency, consistency, and processing time. To address these problems, this study designed and developed a 7-kg-capacity coffee roasting machine to optimize the quality and quantity of the roasting process. This coffee roasting machine uses a mechanical system with a 1 HP electric motor as the main drive, coupled to a 1:60 gearbox to adjust the torque and rotational speed of the stirring shaft. Other main components used are a pan as a roasting medium, pulleys and V-belts for power transmission, and an iron frame to support the entire system. This machine is manually operated: the operator sets the temperature and roasting time based on direct observation, yet it still yields more uniform roasting results than traditional methods. The method used to make the machine is the design-and-build approach, which includes design planning stages using SolidWorks software, material and component selection, fabrication processes (cutting, welding, assembly), and machine performance testing. With this machine, the coffee roasting process becomes more practical and efficient, enabling consistent, high-quality coffee. The study’s implications indicate that the use of simple yet appropriate technologies can significantly increase the efficiency and quality of coffee production at the MSME level. This machine has the potential to increase the productivity and competitiveness of local coffee-processing industry players and to create new business opportunities in the agroindustry sector. In addition, the results of this study contribute to the development of agricultural equipment innovations that align with community needs, particularly in coffee production centers. An important message from this study is the need to adopt affordable, applicable mechanization technologies to strengthen the small- and medium-sized industry sector. This not only supports the sustainability of local coffee businesses but also strengthens the community’s economic independence by increasing the added value of agricultural products.