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The rolling process is a material forming method that is greatly influenced by the roll rotation speed parameter. Inappropriate rotation variations can cause various defects such as waves, tears, thickness irregularities, and ovalization. This review aims to compare the effect of variations in the roll machine rotation speed on the quality of rolling results on various types of materials, including Al6061-O aluminum plate, rubber sheets, and hollow and pipe-shaped materials. The method used is a literature study by collecting and comparing data on roll speed, defects that appear, deformation results, and process efficiency from several relevant journals. The results of the analysis show that high rotation speeds increase productivity but also increase the risk of defects because the material does not have time to adapt to deformation. Conversely, low rotation speeds produce more stable shapes and minimize defects, but are less efficient for mass production. Each material has a different optimal rotation range, including 23–36 rpm for Al6061-O plate, 45–72 rpm for rubber sheet formation, 24.4 rpm for hollow and pipe rolling, and around 21 rpm for corrugated plate. Overall, this study confirms that rotational speed control is a critical factor in achieving a balance between deformation quality and machining efficiency.

In manufacturing industries, machining processes play a critical role in ensuring product quality, precision, and production efficiency. However, in the production of swing arm parts, the machining process has been identified as a bottleneck due to its non-optimal cycle time. One of the main issues contributing to this inefficiency is the disorganized handling of circlip inner parts. These components are often scattered without a designated placement system, which creates significant difficulties for operators when retrieving and installing circlips onto the swing arm. Such abnormalities disrupt workflow continuity, extend production time, and reduce overall productivity. To address this challenge, a circlip feeder machine was designed as a supporting device to assist operators and streamline the machining process. The design emphasizes efficiency, integration, and systematic operation by utilizing readily available workshop materials. The developed feeder machine is equipped with a robust frame construction and has a storage dimension capable of accommodating up to 200 circlips. In addition, mechanical analysis demonstrates that the feeder structure can withstand a maximum applied force of 31,475 N, ensuring durability and reliability during operation. The introduction of this circlip feeder machine directly impacts the production process by reducing operator workload, minimizing delays caused by disorganized parts, and ensuring faster and more accurate installation of circlips. Consequently, the overall machining cycle time is shortened, thereby improving production flow and enhancing the efficiency of swing arm part manufacturing. Beyond immediate time savings, the use of the feeder machine contributes to better resource utilization, reduced ergonomic strain on operators, and improved consistency in product quality. This study highlights the significance of simple yet effective mechanical innovations in overcoming production bottlenecks and optimizing manufacturing processes in automotive component industries.

This study aims to analyze the factors that influence students' learning motivation in the Lathe Engineering subject in class XI of the Department of Machining Engineering at SMK Negeri 1 Padang. Several variables studied include learning interest, ideals, friendship environment, and family environment, each of which acts as an independent variable, while learning motivation functions as a dependent variable. The method used in this study is quantitative with a correlational approach, where the research sample consisted of 51 students selected using a saturated sampling technique, namely sampling that covers the entire population in the class. The instrument used in this study was a questionnaire with a Likert scale that has been tested for validity and reliability to ensure that the measuring instrument used is able to extract accurate and consistent data. The data obtained were then analyzed using multiple linear regression techniques with the help of SPSS version 26 to determine the effect of each variable on student learning motivation. The results of the study indicate that partially, learning interest and friendship environment have a significant influence on student learning motivation. Students who have a high interest in the Lathe Engineering subject tend to have better learning motivation, and positive relationships with their friends also increase their enthusiasm for learning. In contrast, the variables of ideals and family environment did not show a significant influence on students' learning motivation in the context of this study. Although ideals and family support are often considered important factors in education, the results of this study indicate that external factors such as friendships are more dominant in influencing students' learning motivation. Simultaneously, all four variables significantly influenced students' learning motivation, with the friendship environment being the most dominant factor.

This study aims to analyze the electrical energy consumption of a bench-type drilling machine, RYU RDB 13, by varying machining parameters in the form of spindle speed and feed rate. Electrical energy is a critical aspect of production efficiency in the manufacturing industry, particularly in machining processes that require continuous power consumption throughout the cutting operation. The material used in this study is aluminum 6061, chosen for its lightweight, corrosion resistance, and wide application in the automotive and aerospace industries. The drilling process was carried out using three spindle speed variations: 620 rpm, 920 rpm, and 1280 rpm, along with three feed rate variations: 0.04 mm/rev, 0.08 mm/rev, and 0.1 mm/rev. Current and voltage were measured using a digital wattmeter in real-time, and energy consumption was calculated in wattseconds (Ws) using power calculation formulas. The results indicate that increasing the feed rate and spindle speed leads to higher instantaneous power consumption. However, total energy consumption tends to decrease at higher speed and feed combinations due to shorter machining times. The optimal parameter combination was found at a feed rate of 0.1 mm/rev and a spindle speed of 1280 rpm, which resulted in the lowest energy consumption of 387 Ws and the fastest drilling time. This demonstrates that selecting the right machining parameters not only improves energy efficiency but also maintains or enhances productivity. The observed power consumption pattern typically shows a sharp increase at the beginning of the drilling process, a stable phase during the main cutting stage, and a rapid decrease towards the end of the cut. These findings contribute to a better understanding of the relationship between machining parameters and energy efficiency, serving as a basis for developing sustainable production strategies in the manufacturing sector that prioritize energy savings and cost reduction.

Learning activities can run smoothly if accompanied by the availability of appropriate learning media. Learning in the Machining Technology course requires direct practical activities, for example in understanding the use of lathes. The limitations of students' mastery of knowledge when facing the teaching and learning process that tends to be lecture-oriented, causing students' lack of understanding during practice. Learning media that is less interesting causes failure in delivering material, thereby reducing students' interest in learning. This study aims to examine the effectiveness of Real Time Augmented Reality (RT-AR) Lathe media in the learning process of the Machining Technology course in the D-III Study Program, Department of Mechanical Engineering, Faculty of Engineering, Padang State University (FT-UNP). RT-AR media is designed to present interactive visualizations that describe the lathe work process in real time, so that it is expected to improve students' conceptual understanding and practical skills. The study used a quasi-experimental method with a pre-test and post-test design in two groups: the experimental group using RT-AR media and the control group using conventional learning methods. The results showed that there was a significant increase in the learning outcomes of students in the experimental group compared to the control group. In addition, RT-AR media is also able to increase students' motivation and active participation during the learning process. These findings indicate that RT-AR Lathe media is an effective and relevant learning innovation to be applied in vocational engineering education, especially in mastering lathing material.

This study aims to determine the effect of Virtual Reality Box (VR BOX) as a learning medium on students' motivation, interest, and learning discipline in welding practice for grade XI students of the Machining Engineering Department at SMK Negeri 1 Tanjung Raya. The research method used is quantitative with a quasi-experimental design applying the non-equivalent control group design approach. Data were collected through tests and observation and analyzed using validity tests, reliability, normality, homogeneity, t-tests, ANOVA, and coefficient of determination. The results showed that the use of VR BOX significantly influenced students' motivation, interest, and learning discipline. The implementation of VR media created interactive learning, increased student engagement, and reduced fear in welding practice. It can be concluded that VR BOX is an effective instructional medium to improve the quality of vocational practice learning in vocational schools.