Journal of Applied Mechanical Technology

Design and Construction of an Electropneumatic-Based Automatic Tofu Cutting Machine with a Participatory Rural Appraisal and Experimental Approach

2025-07-07T03:10:20+00:00

ABSTRACT – Manual tofu cutting is often time-consuming and less efficient, necessitating innovation to enhance productivity. This study aims to design an automatic tofu cutting machine as a replacement for the manual cutting process. The method used is Participatory Rural Appraisal (PRA) with an experimental approach. The design process involves simulations to determine the machine's technical specifications, resulting in a minimum pneumatic piston diameter of 24 mm, an inertia of 88,281.25, and a maximum stress of 0.24 N/mm². Testing shows that the machine can cut 112 pieces of tofu in 3.8 seconds. These results indicate that the automatic tofu cutting machine significantly improves the efficiency and speed of the cutting process compared to manual methods. This research contributes to the development of more efficient food processing technology applicable to small-scale industries.

Design and Analysis of a Grass Chopping Machine to Increase Animal Feed Efficiency in Cipicung Village

2025-06-16T17:10:23+00:00

The process of chopping grass for animal feed in Cipicung Village, Sumedang Regency, West Java Province still uses manual methods using simple tools such as machetes and sickles. The use of this tool takes a long time, slowing down the feeding process and requiring human labor. Therefore, the manufacture of a grass chopping machine is needed to simplify the chopping process, make time more efficient and to minimize accidents during the chopping process. The design methods used to obtain data include; field surveys, drawing planning, calculations to determine the components to be used. Based on the calculation results, the machine can chop grass as much as 900 kg/hour or 15 kg/minute. For the rotation of the grass chopper blade needed to chop in 1 minute is 937.5 rpm. While the calculation results of the maximum rotation on the axle pulley are 1800 rpm, then the design can be said to be successful because the rotation of the axle pulley has exceeded the rotation of the chopper blade, which is 937.5 rpm. The simulation results obtained a von misses value of 29.664 N/mm² and a maximum displacement of 0.084 mm and a factor of safety on the frame with a maximum value of 1.5.

Strength Analysis of a 3-Wheeled Electric Bicycle Frame for Laboratory Mobility with a Capacity of 150 kg

2025-07-29T03:03:59+00:00

ABSTRACT – The ease of moving from one place to another, especially to carry equipment or test results, is an important necessity. However, accessibility and mobility efficiency are often an obstacle, even more so for individuals with physical limitations. Tricycles provide better stability compared to two-wheeled bicycles, making them suitable for operations in campus or laboratory environments that have limited terrain and are densely active. This research aims to design and construct a three-wheeled electric bicycle frame to support laboratory mobility with a maximum load capacity of 150 kg. The design process follows the Pahl and Beitz method for concept development, with three-dimensional modeling conducted using SolidWorks software, and structural strength analysis performed through Finite Element Analysis (FEA). Manual calculations were also carried out to validate the numerical simulation results. The manufacturing stage involved cutting, bending, and welding hollow steel pipes, with considerations for ergonomics and cost efficiency. Simulation testing indicated a maximum stress of 30.3 MPa, which is significantly lower than the yield strength of ASTM A36 material, resulting in a high safety factor of 8.2. This research contributes to the development of environmentally friendly, efficient, and safe transportation solutions for research environments.

The Effect of G96 and G97 on Surface Roughness of ST 37 and S45C in CNC Turning

2025-06-19T02:37:14+00:00

ABSTRACT – This study aims to compare the effects of Constant Cutting Speed (G96) and Constant Spindle Speed (G97) modes on the surface roughness of ST 37 and S45C materials in step-turning processes using a CNC lathe. A comparative experimental method was employed, measuring surface roughness (( R_a )) at stepped diameters (16 mm, 24 mm, 32 mm, and 35 mm) with a Mitutoyo Surface Tester SJ-210. Results indicate that G96 mode produces lower surface roughness, with average ( R_a ) values of 2.22 µm (S45C) and 2.27 µm (ST 37) in the N6 class, compared to G97 mode with ( R_a ) values of 3.08 µm (S45C) and 3.03 µm (ST 37) in the N7 class. G96 mode is superior due to its ability to automatically adjust rotational speed based on diameter, whereas in G97 mode, small diameters with high rotation (1273 rpm) increase roughness due to vibration or heat. This study recommends using G96 mode for optimal surface smoothness in step-turning of similar materials.

rning of similar materials.

FEM Simulation and Microstructure Validation on the Effect of SMAW Welding Speed on ASTM A36

2025-05-28T09:03:16+00:00

ABSTRACT – Welding is one of the metal joining processes commonly used in the shipping industry, but this process has the potential to cause residual stress and distortion due to uneven heat distribution. This study aims to analyze the effect of welding speed variations on residual stress and distortion in ASTM A36 plate butt joints using the SMAW (Shielded Metal Arc Welding) welding method. The method used in this study is a numerical simulation based on the Finite Element Method (FEM) using ANSYS 2024 R2 software, with welding speed variations of 15 cm/min, 20 cm/min, and 25 cm/min. Validation was carried out through microstructure tests on welding specimens using a metallographic microscope. The simulation results show that the higher the welding speed, the lower the residual stress and distortion values. A speed of 25 cm/min gives the best results with a residual stress of 160,29 MPa and a distortion of 0,1436 mm. The results of the microstructure test in the weld area and HAZ show fine and even grains, supporting the simulation results that high welding speeds produce lower heat input and more stable microstructures. Thus, a welding speed of 25 cm/min is recommended as the optimal parameter in minimizing residual stress and distortion in ASTM A36 plates.

Design and Construction of Flood Water Level Detector Based on Arduino Uno

2025-06-16T04:59:18+00:00

Floods are a disaster that often hits urban areas in Indonesia, especially due to high rainfall and inadequate drainage systems. To reduce the risk of flooding, an effective and automatic early warning system is needed. This study aims to design and develop an air flood height detector based on an Arduino Uno microcontroller with the integration of an HC-SR04 ultrasonic sensor, servo motor, I2C LCD, buzzer, and LED indicator. This system is able to detect air height in real time, display information on the LCD, provide visual and audio warnings, and automatically adjust the position of the air door based on the detected air height level. The test results show that this tool works with high accuracy (error rate <2%) and can respond to changes in air height quickly. This system successfully automates water flow management and provides information that can be used for flood mitigation. Potential future developments include integration with IoT technology and mobile applications for remote monitoring

Optimization of Working Conditions in Pawidean Village Welding Workshop Through Mental Workload Analysis with NASA-TLX Method

2025-06-24T01:05:10+00:00

Micro, Small, and Medium Enterprises (MSMEs) have a strategic role in supporting economic growth in various countries, including Indonesia. One form of MSME that is developing in Indonesia is welding workshops which are classified as light manufacturing industries. This type of work environment has the potential to cause fatigue, stress, and decreased concentration, which can ultimately increase the risk of work accidents. This study aims to measure the level of mental workload of mechanics using the NASA-TLX (National Aeronautics and Space Administration Task Load Index) method, which assesses six main aspects: mental demands, physical demands, time demands, personal performance, effort, and frustration levels. The results of the study showed that operators with the highest mental workload obtained a NASA-TLX score of 88.667, while the lowest was 68.667. This shows that the average workshop operator experiences a high mental workload. The main factors causing this high workload include high time pressure, where the operator must complete the work in a limited time with a limited workforce of only 6 people. To reduce mental burden, workshops can take corrective measures such as providing supporting facilities, simplifying work systems, limiting last-minute orders, implementing re-inspections, and providing incentives for employees who work overtime to increase job satisfaction.