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MODEL MATEMATIK UNTUK MEMPREDIKSI KEKASARAN PERMUKAAN HASIL PROSES CNC BUBUT PADA KONDISI PERMESINAN TANPA PENDINGIN Saputro, Herman
PAWIYATAN Vol 20, No 1 (2013)
Publisher : PAWIYATAN

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Abstract

Turning is one of the machining operations that widely used in variety of manufacturing industries. The quality of surface plays very important role in the performance of turning that significantly improves fatigue strength, and corrosion resistance. It is also affects functional attributes of parts such as light reflection, coating and heat treatment. This research aim to develop a mathematical model to predict surface roughness based on machining parameter selected (spindle speed, feed, and depth of cut) with cutting codition dry. The experiment was tested by using Trun Master TMC 320 Sinumerik 802 S machining center. After 27 specimens were cut for experimental purposes, they were measured off-line with a surface roughness tester to obtain the roughness average value. The surface roughness (Ra) could be predicted effectively by applying spindle speed (n), feed rate (Vf) and depth of cut (a) in the multiple regression model as: Y = -0.1228 – 0.0001 n + 20.940 Vf + 0.7444 a. The  average percentage deviation of the testing set was 6.429 %  for training data set This showed that the statistical model could predict the surface roughness with about 93.571 % accuracy of the testing data set. Keywords : CNC Turning, Surface Roughness, Multiple Linier Regression 
MODEL MATEMATIK UNTUK MEMPREDIKSI KEKASARAN PERMUKAAN HASIL PROSES CNC BUBUT PADA KONDISI PERMESINAN TANPA PENDINGIN Saputro, Herman
PAWIYATAN Vol 20 No 1 (2013)
Publisher : PAWIYATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Turning is one of the machining operations that widely used in variety of manufacturing industries. The quality of surface plays very important role in the performance of turning that significantly improves fatigue strength, and corrosion resistance. It is also affects functional attributes of parts such as light reflection, coating and heat treatment. This research aim to develop a mathematical model to predict surface roughness based on machining parameter selected (spindle speed, feed, and depth of cut) with cutting codition dry. The experiment was tested by using Trun Master TMC 320 Sinumerik 802 S machining center. After 27 specimens were cut for experimental purposes, they were measured off-line with a surface roughness tester to obtain the roughness average value. The surface roughness (Ra) could be predicted effectively by applying spindle speed (n), feed rate (Vf) and depth of cut (a) in the multiple regression model as: Y = -0.1228 – 0.0001 n + 20.940 Vf + 0.7444 a. The  average percentage deviation of the testing set was 6.429 %  for training data set This showed that the statistical model could predict the surface roughness with about 93.571 % accuracy of the testing data set. Keywords : CNC Turning, Surface Roughness, Multiple Linier Regression 
UPAYA MENGURANGI KESULITAN BELAJAR PEMROGRAMAN CNC MILLING DENGAN STRATEGI GENERATIVE LEARNING Saputro, Herman; Widiastuti, Indah
Jurnal Inovasi Pendidikan Vol 12, No 1 (2011)
Publisher : Jurnal Inovasi Pendidikan

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Abstract

This article presents a class action research in the subject of Computer Numerical Controlled (CNC) at the SMK Murni Surakarta. This research aim is improving student ability to create correct CNC program for mill machine. It is found that last class students performed not quite well in this subject. They had difficulty to create CNC mill program logically. Actually, the students possessed appropriate knowledge to imagine the cutting tool movement from subjects related to conventional machine operation However, students were not able to construct that knowledge to develop CNC codes properly. Therefore this research analyzed possibility to implement learning strategy based on constructivism approach that is generative learning strategy. This strategy is directed to ask students to generate their past knowledge with the result that they can understand what their learned on their ways. There were two cycles conducted during the action research, every cycle was consisted of four phases: planning, action, evaluation and reflection phase. At the first phase of 1st cycle, the teacher prepare teaching plan, course material and assessment instrument. Then, the teacher identified initial knowledge and motivation of students to plan the actions by means of question-naire and pre requisite subject score. The first cycle action is focused on tool movement on coordinate form. The evaluation on this cycle showed that students were able to create knowledge from information they have known and they were capable to determine tool direction. Based on this result, in the second cycle the students were asked to create engineering drawing on the millimeter book together with the tool direction. After that, they simulated it by means of Cutviewer mill. There was an increasing in percentage of students do@ the task correctly (74,3%). It shows that generative learning strategy could be an alternative to reduce students' difficulty in CNC programming learning.
EVALUASI PELAKSANAAN MICRO TEACHING DENGAN MENGGUNAKAN MODEL CIPP PADA PROGRAM STUDI PENDIDIKAN TEKNIK MESIN UNIVERSITAS SEBELAS MARET SURAKARTA Cahyono, Rohmat; Akhyar, Muhammad; Saputro, Herman
Jurnal Ilmiah Pendidikan Teknik dan Kejuruan Vol 10, No 2 (2017): JIPTEK : Jurnal Ilmiah Pendidikan Teknik dan Kejuruan
Publisher : Fakultas Keguruan dan Ilmu Pendidikan Universitas Sebelas Maret Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/jiptek.v10i2.16918

Abstract

Tujuan dari penelitian ini adalah untuk mengevaluasi pelaksanaan micro teaching. Penelitian ini dilakukan di program studi Pendidikan Teknik Mesin Universitas Sebelas Maret. Penelitian ini menggunakan model CIPP (Context, Input, Process, Product). Populasi dari penelitian ini adalah mahasiswa pendidikan teknik mesin dan dosen pembimbing micro teaching pelaksanaan tahun 2016. Teknik pengumpulan data menggunakan angket yang disebar kepada seluruh responden, wawancara dengan sebagian responden, dan dokumentasi nilai akhir mata kuliah micro teaching. Validitas menggunakan fact finding yaitu validitas logika. Menggunakan fact finding maka uji reliabilitas tidak perlu dilakukan. Analisa skor menggunakan rata-rata yang akan dinilai berdasar kriteria penilaian. Hasil penelitian menunjukkan sebagian besar pelaksanaan micro teaching sudah baik, tetapi perlu ada perbaikan lagi pada beberapa indikatorKata kunci: Evaluasi Program, Micro Teaching, CIPP
Fostering Entrepreneurial Interest: An Analysis of the Role of Entrepreneurship Education and Skills Competence Nurryna, Ayu Fiska; Widiastusi , Indah; Saputro, Herman
Jurnal Pendidikan dan Pengajaran Vol 58 No 1 (2025): April
Publisher : Universitas Pendidikan Ganesha

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23887/jpp.v58i1.85395

Abstract

Many vocational students have low interest in entrepreneurship, despite having Entrepreneurship Education in the curriculum. It is important to understand the factors that influence entrepreneurial interest, including the role of Entrepreneurship Education and Expertise Competencies. This study aims to analyze the effect of Entrepreneurship Education and Expertise Competencies on entrepreneurial interest of vocational students, both individually and simultaneously. This research uses a quantitative design. The research subjects involved in this research are vocational students selected through cluster sampling technique totaling 211 students. The data collection method used is a questionnaire. The instrument used was a validated questionnaire sheet, and the data were analyzed using linearity test, ANOVA, and regression analysis to see the effect of independent variables on the dependent variable. The results showed that Entrepreneurship Education has a significant influence on students' entrepreneurial interest, while Expertise Competency has no significant effect individually. However, when analyzed simultaneously, these two variables show a significant influence in increasing entrepreneurial interest. In addition, significant differences were found in entrepreneurial interest among different skill groups. This study concludes that the integration between Entrepreneurship Education and Skill Competency in SMK curriculum is important to increase students' entrepreneurial interest. Future research is recommended to expand the geographical coverage and sample for greater validity as well as examine other variables that could potentially affect entrepreneurial interest.
Enhancing Stoichiometric Methane-Air Flames: The Role of N2O Replacement Purwanto, Aris; Saputro, Herman; Alhikami, Akhmad Faruq; Munir, Fudhail Abdul
Automotive Experiences Vol 8 No 2 (2025)
Publisher : Automotive Laboratory of Universitas Muhammadiyah Magelang in collaboration with Association of Indonesian Vocational Educators (AIVE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31603/ae.13422

Abstract

The oxidizer is used in aviation propellants for its relatively high impulse density and non-toxic nature. At elevated temperatures, nitrous oxide (N₂O) decomposes into approximately 33% oxygen (O₂) and 67% nitrogen (N₂), providing a higher oxygen content than ambient air. This decomposition enables N₂O to produce higher flame temperatures than air. Previous studies have shown that N₂O addition improves flame stability in methane combustion systems. This study examined the substitution of O₂ with N₂O in stoichiometric methane–air premixed flames, using both numerical and experimental methods. One-dimensional and two-dimensional simulations with CHEMKIN PRO revealed that replacing air with N₂O increases flame temperature but reduces laminar flame speed, mainly due to lower local oxygen concentrations in the reaction zone. The simulations also showed that nitrogen oxides (NOₓ) emissions increase significantly in the post-reaction zone, while carbon monoxide (CO) and carbon dioxide (CO₂) emissions decrease. Experimental results confirmed that controlled N₂O addition enhances flame stability, but excessive concentrations can trigger combustion instabilities. Overall, the findings indicate that introducing up to 20% N₂O can increase flame temperature and reduce CO emissions in methane flames.