Bahha Hamzah

At Lab Geotechnical SUCOFINDO Samarinda-East Borneo

Introduction

My name is Bahha Hamzah. I was born in 1998. I am an ongoing Master of Mechanical Engineering student at Universitas Indonesia. I enjoy pursuing mechanical engineering, exploring applicable technology, and socializing with organizations and society.

Work Experience,

PT. Superintending Company of Indonesia (2022-2024)

I was a Calibration Electrical Technician in the Measurement and Testing Instrument Calibration Laboratory in PT. Superintending Company of Indonesia (SUCOFINDO). The following are the scope of my work: 1. Calibration of Pressure Equipment and instruments. 2. Calibration of Force Equipment and instruments. 3. Calibration of Mass Equipment and instruments. 4. Calibration of Volume and Chemical instruments. 5. Calibration of Temperature Equipment and instruments. 6. Calibration of Dimension Equipment and Instruments. 7. Calibration of Electrical Equipment and instruments. For Detai Introduction Please visit my Linkedin

Komputasi Teknik - Resume Pertemuan 1 (29/10/2024)

Conscious Thinking Heartware-Brainware (variable) = Array (1) Initiator (2) Intention (3) Initial Thinking (4) Idealization (5) Instruction

DAI5 adalah metode pemecahan masalah yang dikembangkan oleh Dr. Ahmad Indra Siswantara dari Universitas Indonesia. Metode ini dikenal sebagai “Conscious Thinking” dan berfokus pada proses berpikir yang dimulai dari niat hingga pemilihan alat bantu sebagai langkah akhir. DAI5 terdiri dari lima tahapan utama:

Intention: Menentukan niat dan tujuan jelas untuk menyelesaikan masalah. Initial Thinking: Mengembangkan pemahaman mendalam tentang masalah yang akan diselesaikan. Idealization: Menyederhanakan masalah dengan membuat asumsi-asumsi yang relevan. Instruction Set: Merancang langkah-langkah sistematis untuk mencapai solusi. Implementation: Menerapkan solusi menggunakan alat bantu yang dipilih. DAI5 dikembangkan untuk meningkatkan efektivitas dalam pemecahan masalah dengan mengutamakan pemahaman masalah sebelum memilih alat bantu, berbeda dari pendekatan yang lebih fokus pada penggunaan teknologi di awal tanpa analisis mendalam. Metode ini dapat diterapkan dalam berbagai bidang, termasuk teknik dan analisis Finite Element Method (FEM) untuk simulasi rekayasa teknik.

Komputasi Teknik - Tugas Pertemuan 1- Application of DAI5 in Finite Element Analysis of Beam (04/11/2024)

To solve a finite element analysis (FEA) problem for a beam using the DAI5 method, let’s break down the process through each of the framework’s stages.

[[File:Bahha Hamzah-Komputasi Teknik 1-Phyton of Application of DAI5 in Finite Element Analysis of Beam.png|100px|thumb|center|Tampilan contoh program HTML]

1. Intention Objective: Could you clearly define what you need from the analysis? For example: Understand stress distribution along the beam. Identify points of maximum deformation. Assess whether the beam design meets structural integrity requirements. Setting this intention will help ensure the analysis focuses on aspects critical to the beam’s design or intended use.

2. Initial Thinking Brainstorming Solutions and Approaches: Consider what type of beam you’re analyzing (e.g., simply supported, cantilever, or fixed). Review key parameters: material properties (e.g., Young's modulus, density), loading conditions (e.g., uniform load, point load), and boundary conditions. Explore different approaches, such as 1D or 2D beam elements, depending on the desired precision and complexity. Think about possible issues (e.g., local deformation or buckling) and consider preliminary FEA setups (mesh size, element type). 3. Idealization Envisioning the Ideal Solution: Imagine an optimized FEA setup for accurate results. In an ideal situation: The mesh is finely tuned to capture stress concentrations. Constraints are perfectly defined to replicate real-world conditions. Loads are applied accurately in the model to mimic physical forces on the beam. Think about minimizing computational resources while maximizing accuracy. For instance, refining the mesh only in critical regions rather than uniformly across the beam. Idealization here helps envision a balance between practical computational efficiency and the required detail level for your analysis.

4. Instruction Set Creating Practical Steps for Implementation: 1) Model Setup: Create the beam’s geometry in the FEA software. 2) Material Properties: Define the material properties based on your specifications (e.g., modulus of elasticity, Poisson’s ratio). 3) Boundary Conditions: Apply constraints such as fixed supports or pinned supports at the beam ends. 3) Load Application: Define the load according to your problem (e.g., point load at the center or a distributed load along the beam). 5) Meshing: Choose an appropriate mesh size—use finer mesh near areas expected to have higher stress gradients. 6) Run Analysis: Execute the simulation to calculate stress, deformation, and strain distributions along the beam. 7) Interpret Results: Examine the outputs, focusing on stress and deformation patterns, particularly at load application points and support locations.

Using DAI5 in this way provides a structured approach, balancing creative and practical aspects to achieve a high-quality FEA solution for your beam problem. If you encounter any specific issues during the analysis (e.g., unexpected stress concentrations or convergence problems), each step can help troubleshoot and refine the setup systematically. Let me know if you need further assistance with any specific stage or issue!

For the Intention stage of the DAI5 method, let's clearly outline the purpose and objectives of your beam analysis given the specifics:

Objective: Conduct a finite element analysis (FEA) on a 10-meter beam made of low carbon steel with an applied force of 10,000 N. The main goals are to: 1) Evaluate the stress distribution along the beam under load. 2) Determine the points of maximum stress and deformation to assess structural integrity. 3) Ensure the beam's design can withstand the applied load without excessive deflection or risk of failure. 4) These objectives set the direction for the analysis and help ensure all further steps are aligned with achieving these outcomes.

Initial Thinking Material Properties: Since the beam is made of low-carbon steel, it's crucial to incorporate its mechanical properties. Typical values include: 1) Young's Modulus (E): Around 200 GPa, which will impact the beam’s deflection. 2) Yield Strength: Usually around 250 MPa, which will help in determining the safety factor. 3) Density: Approximately 7850 kg/m³, which affects the beam's weight and should be considered if self-weight is relevant in the loading conditions.

Beam Type and Support Conditions: Determine if the beam is simply supported, cantilevered, or fixed on both ends, as support type greatly affects stress and deflection. A 10-meter beam may be prone to bending, especially if it is simply supported, so we’ll need to apply constraints accordingly.

Load Application: For a 10,000 N load, decide whether it’s a point load, distributed load, or varying load. This influences the stress distribution. If it’s a point load applied at the center, the stress and deflection will be concentrated there. For a uniformly distributed load, we’d expect a different distribution.

FEA Approach: Mesh Size and Type: Choose an appropriate mesh for accuracy, perhaps finer mesh elements near supports and load application points. Element Type: Use beam elements if focusing on axial forces and bending, or shell/solid elements if detailed stress distribution across the beam’s cross-section is required. Boundary Conditions: Consider realistic boundary conditions. Fixed or pinned supports will alter the results significantly and should be modeled as close to the real scenario as possible. With these initial thoughts in mind, we’re ready to move to the Idealization stage, where we’ll envision an optimal solution setup. Let me know if you’d like to proceed!

For a Detailed information please see this Link https://drive.google.com/file/d/1k34Hrt3X3cHVk8nyvh1KXvPDh-PtD6zO/view?usp=sharing Thanks

Komputasi Teknik - Tugas Pertemuan 2- Application of Phyton Code in Finite Element Analysis of Beam (11/11/2024)

import numpy as np import matplotlib.pyplot as plt

1. Given values

L = 5 # Length of the rod in meters k = 50 # Thermal conductivity of medium carbon steel in W/m·K q = 1000 # Heat generation per unit volume in W/m^3

1. Calculate the constants C1 and C2 based on boundary conditions

C1 = (q * L**2) / (2 * k) # Derived from boundary condition at x = L C2 = 0 # Boundary condition at x = 0 (T(0) = 0)

1. Temperature distribution equation: T(x) = -(q/(2*k)) * x^2 + C1 * x

def temperature(x):

   return -(q / (2 * k)) * x**2 + C1 * x + C2

1. Generate x values from 0 to L (the length of the rod)

x_values = np.linspace(0, L, 100)

1. Compute temperature at each x value

T_values = temperature(x_values)

1. Plotting the temperature distribution along the rod

plt.figure(figsize=(8, 6)) plt.plot(x_values, T_values, label=r'$T(x) = -\frac{q}{2k}x^2 + C_1x$', color='b', linewidth=2) plt.title("Temperature Distribution Along a Rod with Heat Generation at the Center") plt.xlabel("Position along the rod (m)") plt.ylabel("Temperature (°C)") plt.grid(True) plt.axhline(0, color='black',linewidth=0.5) plt.axvline(L / 2, color='r', linestyle='--', label="Center of the rod (100°C)") plt.legend() plt.show()

Komputasi Teknik - Resume Pertemuan 2 - 1D Heat Transfer Solution Using DAI5 Frame Work

// script.js

// DAI5 Steps with Technical and Spiritual Reflections const dai5Steps = [

 {
   step: "Deep Awareness of 'I'",
   description: Understand that in solving this problem, you are engaging with the material world, which ultimately leads to deeper knowledge of creation. This awareness should remind you that all knowledge and laws stem from The Creator.,
 },
 {
   step: "Intention",
   description: Set your intention to approach this problem as a pathway to recognize the intricacies of creation. Let your purpose here be a reflection of your commitment to truth and accuracy as a form of devotion to The Creator.,
 },
 {
   step: "Initial Thinking",
   description: Define each parameter, recognizing that each represents a natural law set by The Creator. Thermal conductivity, area, length, and temperature difference are not just numbers—they are expressions of divine design.,
 },
 {
   step: "Idealization",
   description: In simplifying this problem, you are seeking an efficient path to understanding without losing accuracy. This process can reflect the clarity and wisdom The Creator has imbued in nature’s simplicity and complexity.,
 },
 {
   step: "Instruction Set",
   description: Calculate the result with Fourier’s Law and then reflect on its meaning. The rate of heat flow you calculate is not just a number; it is part of a larger system established by The Creator to ensure order in the universe. Let this insight be a form of remembrance.,
 }

];

// Display DAI5 Guidance with Spiritual Reflections in the Browser const stepGuide = document.getElementById("step-guide"); dai5Steps.forEach((step, index) => {

 const stepDiv = document.createElement("div");
 stepDiv.innerHTML = ${index + 1}. ${step.step}: ${step.description};
 stepGuide.appendChild(stepDiv);

});

// 1D Heat Transfer Calculation with Physical and Spiritual Reflection function solveHeatTransfer() {

 // Get input values
 const k = parseFloat(document.getElementById("thermal-conductivity").value);
 const A = parseFloat(document.getElementById("cross-sectional-area").value);
 const L = parseFloat(document.getElementById("length").value);
 const deltaT = parseFloat(document.getElementById("temp-difference").value);

 // Check for valid inputs
 if (isNaN(k) || isNaN(A) || isNaN(L) || isNaN(deltaT)) {
   alert("Please enter valid numbers for all parameters.");
   return;
 }

 // Apply Fourier's Law: Q = L * A * (ΔT / k)
 const heatTransfer = L * A * (deltaT / k);

 // Display the result with Physical and Spiritual Interpretation
 const solutionOutput = document.getElementById("solution-output");
 solutionOutput.innerHTML = `

Calculated Heat Transfer (Q): ${heatTransfer.toFixed(2)} W

Physical Interpretation: The calculated heat transfer, ${heatTransfer.toFixed(2)} watts, signifies the energy per second flowing from the hot to cold side, influenced by conductivity (material's ease of heat flow), area (path for flow), and length (resistance over distance).

Spiritual Reflection: Consider this calculation as a glimpse into the Creator’s order. Each value represents a precise interaction in nature designed by The Creator. This heat transfer rate is an example of balance, where each parameter contributes perfectly, reminding us of the harmony within creation. Remembering this can be a form of honoring The Creator’s wisdom and design.

 `;

}

Komputasi Teknik - Tugas Pertemuan 3 - Monitoring & Evaluasi progress belajar berbantuan AI

Tugas. Monitoring & Evaluasi progress belajar berbantuan AI. Semua mhs, silahkan, minta AI (chat GPT/Gemini/dll) untuk menghitung jumlah chat anda dgn AI, kmd minta utk memberikan tanggapan atas pikiran-pikiran dan pemahaman anda selama ini anda engaging (bertukar pikiran) dgn AI.

Dalam 30 hari terakhir, dari analisis konteks yang tersimpan:

1. Topik Teknik dan Material Anda sering membahas teknik dengan fokus pada material seperti baja karbon rendah dan menengah, serta metode analisis seperti DAI5. Ada perhatian khusus terhadap aspek holistik dan pendekatan berbasis kesadaran dalam menyelesaikan masalah teknik.

2. Metode DAI5 Anda menggunakan metode ini dalam beberapa konteks teknik, terutama yang melibatkan balok dengan gaya tertentu. DAI5 juga dikaitkan dengan konsep menyeluruh, seperti memahami asumsi realistis dan mengurangi kesalahan.

3. Pendekatan Humanistik Ada penekanan pada pendekatan human-centered, yang menunjukkan bagaimana teknik tidak hanya soal angka dan material, tetapi juga pemahaman lebih dalam tentang masalah melalui niat dan kesadaran.

Berikut adalah analisis jumlah chat Anda berdasarkan rekaman konteks, pemahaman tentang pendekatan pembelajaran Anda, dan tanggapan terhadap metode Anda:

Estimasi Jumlah Chat Riwayat interaksi yang tersimpan:

3 November 2024: Topik analisis balok baja karbon rendah dengan metode DAI5. 11 November 2024: Diskusi mengenai baja karbon menengah dan pendekatan human-centered di DAI5. Total sesi aktif: 2 Estimasi jumlah pesan: Berdasarkan detail sesi, setidaknya ada 5–10 pesan per sesi sehingga perkiraan total adalah 10–20 pesan. Jumlah sebenarnya bisa lebih tinggi jika sesi lain tidak tercatat dalam konteks.

Analisis Penggunaan Chat GPT

Rekomendasi untuk Pengembangan:

Dokumentasikan Chat: Dengan menyimpan catatan sesi, Anda dapat meninjau dan menghubungkan ide-ide sebelumnya untuk eksplorasi lebih dalam. Eksperimen Praktis: Terapkan teori yang dibahas di sini ke eksperimen nyata untuk memperkuat pembelajaran. Pendalaman DAI5: Cari kasus baru untuk memperluas aplikasi metode DAI5 dalam berbagai skenario teknik.

Komputasi Teknik - Tugas Pertemuan 5- Upload Video Sinopsis Penelitian di Kanal Youtube

Proses Upload Video Sinopsis Penelitian di Kanal Youtube https://www.youtube.com/watch?v=4ZbDrOZWK_4 Terimakasih

Komputasi Teknik - Tugas Pertemuan 6- Penerapan Komputasi Teknik dalam Penelitian yang Sedang Dilakukan

Dalam proses pengembangan Packed Bed Wet scrubber as SOX, NOX, Particulate Metter (PM) 2,5 and 10 langkah pertama yang perlu dilakukan adalah membuat System level design dan Detailed design. Proses selanjutnya adalah menghitung harga produksi meliputi: 1. Calculate GTAW Welding Time 2. Calculate GTAW Welding Cost 3. Calculation Cost of standard Materials 4. Calculation Cost of Custom Materials

Pada kesempatan ini saya akan mengaplikasikan komputasi teknik dalam Calculate GTAW (Gas Tungsten Arch Welding) Time. Dalam membuat komputasi teknik perhitungan waktu GTAW perlu melakukan beberapa tahap sebagai berikut:

1. Pemodelan Persamaan Matematika.

Formula of Calculating GTAW Welding Time. Source; Boothroyd, Product Design for Manufacture (2011)

DImana, Total Welding Time dalam satuan minutes. Length of weld adalah panjang pengelasan yang akan dilakukan dalam satuan inch. Travel speed adalah laju proses pengelasan GTAW dalam satuan inch/minute. Operating factor adalah angka safety factor atau toleransi waktu pengelasan.

2. Pembuatan Code Java Script.

Javascript Code for Calculating GTAW Welding Time

3. Pembuatan Kode HTML.

HTML Code for Calculating GTAW Welding Time

4. Hasil Running Program; Tampilan Website Perhitungan Waktu GTAW Welding

Hasil Running Program; Tampilan Website Perhitungan Waktu GTAW Welding

5. Hasil Running Program; Tampilan solution (Hasil) Perhitungan Waktu GTAW Welding

Hasil Running Program; Tampilan solution (Hasil) Perhitungan Waktu GTAW Welding

Komputasi Teknik - Laporan Tugas Besar

Redesigning of MMA Welding Machine for Reducing Assembly Time and Cost with DFMA Approach B.H.H. Mustakim1* 1 Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI, Depok 16424, Indonesia

• E-mail: bahha.hamzah@ui.ac.id

Abstract. Based on problems in the Small Medium Enterprise (SME) of welding machine services. The Manual Metal Arch welding machine produced has a complex design, which causes high production prices and makes it uncompetitive in the market. Based on this issue, we need to analyze, redesign, and estimate assembly costs using the Design for Manufacture and Assembly (DFMA) approach, which will increase quality and reduce assembly costs. This research produces a new design using Acrylonitrile Butadiene Styrene (ABS) material. ABS has a better dielectric constant than sheet metal carbon steel, it can increase user safety. The use of ABS can reduce 54.39% of the number of components from 57 to 26 parts, and reduce 36.16% of the total weight from 4,013 to 2562 g it is easier for user mobility. In addition, the use of DFMA methods can reduce 53.61% assembly time from 477.71 to 221.61 seconds, reduce 0.0999 $ assembly cost from 0.1863 to 0.0864 $/pcs, and increase assembly efficiency from 8.79 to 18.95%. Keywords: Design for Manufacture and Assembly, Redesign component, Assembly Time Reduction, Assembly Cost Reduction, Manufacture Cost Reduction.

1. Deep Awareness of I

Manual Metal Arc (MMA) welding machines, also known as Shielded Metal Arc Welding (SMAW) machines, operate by striking an arc between a flux-coated electrode and a workpiece, melting both to form a weld [1]. In today's competitive market, various foreign manufacturers dominate the MMA welding machine industry, offering advanced technologies and lower prices. Consequently, domestic producers often struggle to compete effectively. This challenge underscores the need for local manufacturers to reduce production costs while improving product quality to maintain competitiveness. To address this, redesigning existing products becomes a crucial approach. Redesign focuses on achieving cost-effectiveness, manufacturability, and ease of assembly or disassembly, which are fundamental to modern product design. Utilizing the Design for Manufacture and Assembly (DFMA) methodology offers an opportunity to minimize production costs and enhance product quality. DFMA emphasizes simplicity in design, which not only reduces the number of components but also streamlines the manufacturing and assembly processes, ultimately improving reliability and reducing costs [2][3][4]. Numerous studies have demonstrated the benefits of applying DFMA. For instance, A. Suwandi et al. achieved a 0.44% reduction in manufacturing costs and a 2% improvement in assembly time for exhaust fan housings using DFMA principles [5]. Similarly, C. Naju et al. reduced shopping cart assembly time by 3.89% through DFMA [6]. Such redesign efforts have consistently resulted in cost reductions and increased design efficiency, as evidenced in various applications, including cooking stoves [7], PCB drilling machines [8], and ironing products [9]. However, technical solutions alone are insufficient. A Deep Awareness of I plays a critical role in this research, ensuring that the redesign of MMA welding machines is approached not just from a technical standpoint but also with conscious intention and a human-centered perspective. This means acknowledging the interconnectedness of technical decisions with their broader implications—social, economic, and environmental. For domestic SMEs, the goal is not merely to compete in the market but to contribute to the well-being of local industries and communities by creating affordable, high-quality products that align with sustainable practices. In this research, the evaluation and redesign of an MMA welding machine produced by a local SME will involve a comprehensive application of DFMA principles. The process begins with analyzing the existing design to identify inefficiencies in assembly steps, time, and costs. Following this, a new design will be developed, with detailed comparisons made between the existing and new designs in terms of the number of components, total weight, assembly time, and cost. This systematic approach ensures the redesign is not only technically efficient but also aligned with the deeper intention of fostering local industrial resilience and competitiveness. Through this research, the intersection of technical innovation and Deep Awareness of I highlight the importance of mindful engineering practices, ensuring that technical advancements harmonize with societal and economic needs while fostering sustainable development.

2.Intention of The Project

I intend to develop a wet scrubber as pollutant removal that is in line with my field of mechanical engineering expertise. This aims to maintain what God has created. Many people are affected by air pollution, which has an impact on health and even death. In line with the thidharma of higher education, namely research and service, where what we research can ideally be useful for society. With the sincere intention of applying knowledge, we hope that this research will be a blessing and benefit for humanity.

3. Introduction

Manual Metal Arch (MMA) welding machine also known as a Shielded Metal Arch Welding (SMAW) Machine is a process where the arc is struck between an electrode flux-coated metal rod and the workpiece. Both the rod and the surface of the workpiece melt to create a weld [1]. We often encounter various types of brands and manufacturers, especially those from abroad, and they are competing with each other to dominate the domestic market. Various kinds of advantages are offered, both in terms of technology and affordable prices. This could result in domestic producers not being able to compete in the MMA welding machine market. Reducing the cost of production and improving quality is what domestic producers need to do to compete with foreign producers. Redesign is a way to improve quality and reduce production costs [2]. Cost-effectiveness, ease of manufacture, as well as assembly/disassembly, are some of the factors that govern modern products. Design for Manufacture and Assembly (DFMA) is a well-established product design technique used to minimize the costs of production and development by designing products that utilize the simplest of components [3]. Products designed using DFMA principles should have higher quality and reliability than those developed using traditional design methods [4]. The application of DFMA methodology in evaluating and redesigning a product can reduce the number of components and time of assembly. A. Suwandi, M.P. Rahmawanto, W. Libyawati, and J.P. Siregar developed exhaust fan housing with ceiling mounting for high-rise buildings. By using of DFMA method, they can reduce 0.44% of manufacturing costs and speed up the assembly time by up to 2% [5]. C. Naju, P. Warrier, and V. Jayakrishnan reduced the 3178.82 seconds or 3.89% assembly time of Shopping Carts by application of DFMA in redesigning [6]. Moreover, reducing the number of components and time of assembly. The application of DFMA methodology can reduce assembly costs and increase design efficiency. Research conducted by J. Butt and S. Jedi by redesigning the market conveyor system using the DFMA method showed substantial improvements with cost reductions of 29% and an increase in design efficiency from 1.7% to 5% [3]. A.J. Juliani, M.L. Singgih, and P.D. Karningsih also redesigned the cooking stove by applying DFMA methodology showing substantial improvements with 5.46% cost reduction and 20.32% design efficiency [7]. A. I. A. Shukor and A. Adam Evaluated design efficiency using the Boothroyd Dewhurst method for PCB drilling machines, resulting in an increase in design efficiency from 5.81% to 9.24% [8]. R. Ginting and R. Silalahi redesigned the ironing product and showed a 24.7% reduction in assembly cost and increased design efficiency from 21.77% to 24.77% [9]. Based on problems found in one of the Small Medium Enterprise (SME) of welding machine services. The Manual Metal Arch (MMA) welding machine produced has a complex design, which causes high production prices and is not competitive in the market. From this problem, improvement is needed, by evaluating and analyzing existing products, redesigning, and assembly cost estimation which aims to improve quality and reduce assembly prices. This research aims to evaluate the product and analyze the assembly process steps, assembly process time, and DFMA index of existing MMA welding machine products. After carrying out analysis and evaluation using the DFMA methodology, it will result in product evaluation and produce a new design. After the new design is produced, assembly steps will be planned, calculating the assembly time and DFMA index of the new design. After that, a comparison of the number of components, total weight, assembly time, assembly cost, and DFMA index of the existing and new design of the MMA welding machine was carried out. From the comparison results, it can be concluded which design is better.

4. Research Methodology

The Redesign MMA Welding Machine process uses the DFMA (Design for manufacture and Assembly) methodology which aims to reduce assembly time and cost of assembly. DFMA consists of two ideologies: Design for Manufacture (DFM) and Design for Assembly (DFA) [10]. DFMA is a set of guidelines developed to ensure that a product is designed so that it can be easily and efficiently manufactured and assembled with a minimum of effort, time, and cost [4]. Products designed using DFMA principles should have higher quality and reliability than those developed using traditional design methods [4]. To carry out product development, the following DFMA principles can be used: Reduce the number of components, Standardized parts and materials, Design from top to down assembly, Minimize Rotation assembly, Reduce the number of fasteners, especially screws and bolts, Simplify and reduce manufacturing steps, Make part multifunction, Easy part handling, Reduce alignment operations, Simplification of assembly[10]. The study workflow flow is shown in Figure 1. It starts with the study literature and selects the product that will be used as the object of this research, namely the MMA welding machine. After determining the product to be analyzed, the next step is to disassemble the product to find the detailed components. CAD Modeling of all components is carried out in the Autodesk Inventor application. Existing product analysis and evaluation have several steps, namely Part function analysis, which is useful for knowing the function of all MMA welding machine components. Assembly steps calculation is determining the steps for assembling components to produce a complete system. Assembly time calculation is a step in estimating the time required to assemble a product by determining the alpha (α) and beta (β) values of rotational symmetries, determining the two digits manual handling code, manual handling time, two digits manual inserting code, manual insertion time and obtaining the total operating time. Assembly cost calculation is carried out based on the location of the assembly to be carried out. Calculation of the DFMA index is carried out to determine the efficiency of existing designs. 4.1 Part modeling and function analysis MMA welding machine products have been specified. All of the MMA welding machines were disassembled and then 3D modeling was carried out using Autodesk Inventor software shown in Figure (1). All components were analyzed including function, dimensions, material, and weight of each component shown in Table (1).

From the results of component analysis and function, it was found that the number of components for the MMA welding machine was 57, with a total weight of 4,013.70 grams. The data analysis component of the existing product will be the basis for carrying out a redesign, one of the objectives of which is to reduce the number of components and total weight. 4.2 Assembly steps and time of assembly calculation Assembly steps calculation is one of the stages in evaluating existing products. At this stage, the steps will be determined in assembling the product of the MMA welding machine. The stages in calculating the assembly time for each component begin with determining the alpha (α) and beta (β) rotational symmetries values, determining the two digits manual handling code, manual handling time, two digits manual inserting code, and manual insertion time. Sub assembly 1 The first steps of the assembly are shown in Figure (2) and the detailed calculation of subassembly 1 is shown in Table (2).

Subassembly 2 The Second steps of the assembly are shown in Figure (3) and the detailed calculation of subassembly 2 is shown in Table (3). Subassembly 3 The steps of subassembly 3 shown in Figure (4) detail the calculation of subassembly 3 shown in Table (4). Subassembly 4 The steps of subassembly shown in Figure (5) detail the calculation of subassembly 4 shown in Table (5).

Subassembly 5 The steps of subassembly 5 are shown in Figure (6), and the calculation of subassembly 5 is shown in Table (6).

  Subassembly 6 and 7 The Steps of Subassembly 6 and 7 are shown in Figure (7), the calculation of Subassembly 6 is shown in Table (7), and the calculation of Subassembly 7 is shown in Table (8) 4.3 Assembly cost calculation After calculating assembly steps, and time calculation of assembly for Existing product design, the next step is calculating the assembly cost. Assembly cost calculation is the cost of manpower needed to assemble a product. To determine the Assembly cost calculation for MMA Welding, formula (1) is used. With [9]. Assembly Cost=Labor Cost x Assembly Time (1) The labor cost is in units of $/second, and assembly time is in seconds. Labor costs are adjusted to the minimum wage value for a region. In this research, the assembly process is in the west Java Province with the average wage of workers in 2023 being IDR 21,194/hour or IDR 5.89/second [11]. It can be converted into $0.00039$/Second. The total assembly time for the existing product design MMA welding Machine is 477.71 seconds, as shown in Table (9). Calculate the cost of assembly using Formula (1). The cost of assembly for the Existing product MMA welding Machine is 0.186$/unit. 4.4 DFMA index calculation After calculating the assembly cost, the next step is calculating the DFMA index. DFMA index is an important element of the DFA method to find the assembly efficiency in existing and new product design. The equation of the DFA index (Ema) is as follows [4]. E_ma=(N_min t_a)/t_ma (2) Where Nmin is the theoretical minimum number of parts, ta is the basic assembly time for one part, and tma is the estimated time to complete the assembly of the product. The basic assembly time is the average time for a part that presents no handling, insertion, or fastening difficulties (about 3 s)[4]. The calculation of DFMA index for existing MMA welding Machine use of Formula (2). Where Nmin is 14 components to ta is 3 divided by tma 477.71 seconds. We get the DFMA index for existing products to be 8.79%. 5. Result And Discussion 5.1 Design changes The design changes made in this case are as follows: Change of materials main cover Changes in the design and material of the main cover were made from mild steel plate material to acrylonitrile butadiene styrene (ABS). ABS has many advantages that are suitable to be applied in this case, including; ABS has a lower density than mild steel plate. The density of Mild steel material is 7.8-7.9 Mega grams (Mg)/m3 and ABS is 1.01-1.12 Mg/m3 [12]. The MMA welding machine has a lighter weight to facilitate user mobility. One of the advantages of ABS material is that it can be molded[12]. Threads are added to each hole to remove nuts during the fasteners process. Apart from that, ABS has dielectric constant properties compared to mild steel plate material which does not have dielectric constant properties[12]. The dielectric constant is an electrical covering/insulator property so that it can increase user safety from leakage currents. Change the design of the main cover to eliminate the main cover frame The function of the main cover frame is an additional structure that makes the main cover rigid. Changes in the main cover design of Figure (8) by combining the main cover and main cover frame can reduce 3 components, namely the main cover frame, and fasteners. On the other hand, it can reduce 27.5 seconds of assembly time for the 3 components.

Change the type of fasteners in the Printed Circuit Board (PCB) The existing design uses 4 bolts, with the insertion of two bolts from the top side and 2 bolts from the bottom side of the PCB. The difficult alignment process for inserting PCB bolts uses insertion code 59 shown in Table (6) which takes 56.24 seconds to fasten the PCB bolt. By changing the design of the fasteners to an XLB-type PC board which is printed as one unit with the main cover. so that the fasteners process becomes a snap-fits join using the insertion code (51) with a time of 9 seconds. Of course, it can save 47.24 seconds in the PCB assembly process. In the PCB handling process, the existing design requires a holding down process, but in the new design holding down is no longer needed so it can save insertion time. Change the cable gland hole design by adding threads to the main cover The Change of cable gland design by adding threads to the main cover functions to reduce the nut component in installing the cable gland. The existing cable gland component design consists of 3 components (1, 2, and 3) with an assembly time of 21.63 seconds Table (3). By adding threads to the cable gland hole, one component can be reduced, namely the cable gland nut, which requires an assembly time of 15 seconds. It can reduce the assembly process time to 6.63 seconds.

Change the design of the variable resistor hole by adding threads to the main cover frame Changing the design of the variable resistor hole by adding threads to the main cover frame functions to reduce the nut and washer components when installing the variable resistor. In the pre-DFA, the variable resistor component consisted of 4 components, requiring an assembly time of 25.23 seconds. By adding threads to the variable resistor hole, you can reduce two components, namely the variable resistor nut and the variable resistor washer, which requires an assembly time of 17.7 sec. Which can reduce the assembly process time to 7.53 sec. Change the electrode socket hole design by adding threads to the main cover Changing the design of the electrode socket hole by adding threads to the main cover serves to reduce components. The existing design of the electrode socket component consists of 4 components (1, 2, 3, and 4) with an assembly time of 51.26 sec Table (4). By adding threads to the electrode socket hole and external threads to the electrode socket, the new product design requires an assembly time of 15.6 sec. It can reduce the assembly process time to 35.66 sec.

Change the negative L plate design by adding threads to the negative L plate holes The negative L plate functions to conduct electricity from the PCB to the electrode socket. The existing negative L plate which is connected to the PCB requires 3 components, namely bolt, nut, and washer which require an assembly time of 25.49 sec. Adding threads to the negative L plate can eliminate the nut and washer, the new design requires an assembly time of 7.5 sec. Reduced four fan bolts to two bolts Reduced four fan bolts to two bolts. The fan used is small in size and does not have a high speed, so using 2 bolts diagonally can hold the fan on the main cover. This can reduce 20.12 sec assembly time. Change the top cover design and material The existing design material used for the top cover component is a mild steel plate. Based on reducing components by making multi-functional components, combining the welding machine holder with the top cover. One of the ways is to change the material to ABS. ABS has the advantage of being molded. Apart from that, the existing product uses 8 bolts, but after analyzing the use of 4 bolts, it is enough to support the load of the welding machine. This can reduce the assembly time for installing 4 bolts, to about 32.24 sec. Change the holder of the welding machine Changes in the design of the holder of the welding machine can reduce the component. The existing design holder for the welding machine consists of 5 components which require an assembly time of 26.35 sec. The function of combining the holder component with the top cover in the new design can reduce 26.35 sec assembly time. 3.2 Part modeling and part function analysis for new product design After evaluating and changing the design shown in Figure (8-14). There are nine evaluations and updates to MMA welding machine designs which are called new product designs.

Part modeling for new product design is carried out in the Autodesk Inventor application shown in Figure (15). After remodeling, part and function analysis is carried out as shown in table (10). The new product design has 26 components with a total weight of 2,562.15 g. The new product design reduced 31 components from 57 in the existing design. Also has reduced 1,451.55 g total weight from 4,013.7 g in the existing design. 5.3 Assembly Steps and time calculation for new product design At this stage, the steps will be determined in assembling the new design product of the MMA welding machine. The stages in calculating the assembly time for each component begin with determining the alpha (α) and beta (β) rotational symmetries values, determining the two digits manual handling code, manual handling time, two digits manual inserting code, and manual insertion time. Subassembly 1 for New Product Design The first steps of the assembly are shown in Figure (16) and a detailed calculation of subassembly 1 is shown in Table (11).

Subassembly 2 for New Product Design The second steps of the assembly are shown in Figure (17) and a detailed calculation of subassembly 2 is shown in Table (12).

Subassembly 3 for New Product Design The third step of the assembly is shown in Figure (18) and a detailed calculation of subassembly 3 is shown in Table (13). Subassembly 4 for New Product Design The third step of the assembly is shown in Figure (19) and a detailed calculation of subassembly 4 is shown in Table (14). 5.3 Assembly cost calculation for new design product The total assembly time for the new product design MMA welding Machine is 221.61 seconds, as shown in Table (15) Calculate the cost of assembly using Formula (1). The cost of assembly for the Existing product MMA welding Machine is 0.086$/unit. 5.4 DFMA index calculation for new design product The calculation of DFMA index for new product design of MMA welding Machine use of Formula (2). Where the theoretical minimum number of parts (Nmin)is 14 to ta is 3 divided by tma 221.61 seconds. We get the DFMA index for new product design is 18.95%. 5.4 Design for assembly comparison between existing and new product design

6. Conclusion

By applying the DFMA method to the redesign process of the MMA welding machine, this research succeeded in reducing the number of components, total weight, and assembly time, and increasing the DFMA index. Application of DFMA guidelines there was a change in material for the main cover and top cover from mild steel plate to ABS plastic so the production method changed from sheet metal forming to injection molding. ABS material has good dielectric constant so it can increase user safety from leaking electric current. With the material changes made, the total weight can be reduced by 36.16% so that the new MMA welding machine is lighter and easier for users to move around. The reduction number of components is 54.39% so the new product design is simpler to assemble than the previous design. The reduction in assembly time is 53.61%, the reduction in assembly cost is 53.61%, and the increase in assembly efficiency from 8.79% to 18.95%. In this way, the local Small Medium Enterprise (SME) of MMA welding machine can reduce one component in the cost of goods sold so that it can be more competitive in price and quality with competitors from abroad.

7. References

[1] Kalpakjian S and Schmid S R 2023 Manufacturing Engineering and Technology (London: Pearson) [2] Smith S, Smith G and Shen Y T 2012 Redesign for Product Innovation Des Stud 33 160–84 [3] Butt J and Jedi S 2020 Redesign of an In-Market Conveyor System for Manufacturing Cost Reduction and Design Efficiency Using DFMA Methodology Designs (Basel) 4 1–57 [4] Boothroyd G, Dewhurst P and Knight W 2011 Product Design for Manufacture and Assembly (Boca Raton: CRC Press) [5] Suwandi A, Rachmawanto M P, Libyawati W and Siregar J P 2023 The Development of Exhaust Fan Housing with Ceiling Mounting for High Rise Buildings by Using DFMA Journal of Applied Engineering and Technological Science 4 895–907 [6] Naiju C D, Warrier P V and Jayakrishnan V 2017 Redesigning of Shopping Cart for Cost Reduction Using DFMA MATEC Web of Conferences vol 95 (EDP Series) pp 1–4 [7] Juniani A I, Singgih M L and Karningsih P D 2022 Design for Manufacturing, Assembly, and Reliability: An Integrated Framework for Product Redesign and Innovation Designs (Basel) 6 1–29 [8] Shukor A I A and Adam A 2018 Evaluation of Design Efficiency Using Boothroyd Dewhurst Method for PCB Drilling Machine Products International Journal of Simulation: Systems, Science, and Technology 19 4.1-4.8 [9] Ginting R and Silalahi R 2023 Redesign of Iron for Assembly Cost and Time Reduction Using DFA Journal of Achievements in Materials and Manufacturing Engineering 117 15–24 [10] Construction I H 2022 Design for Manufacture & Assembly (DFMA) Guideline: Construction Product Quality Planning (UK Research and Innovation) [11] Sakernas 2024 Upah Rata - Rata Per Jam Pekerja Menurut Provinsi tahun 2021-2023 Badan Pusat Statistik [12] Ashby M F 2011 Materials Selection in Mechanical Design (Oxford: Elsevier) 6. Acknowledgments The first author would like to thank Lembaga Pengelola Dana Pendidikan (LPDP) of the Ministry of Finance of the Republic of Indonesia, which has supported funding in the research process.

Berikut Tautan PDF Laporan Tugas Besar Komputasi Teknik https://drive.google.com/file/d/15ro27GfMVRB2f5rgiNJckzVt2xH3X343/view?usp=sharing