MODEL MATEMATIK UNTUK MEMPREDIKSI KEKASARAN PERMUKAAN HASIL PROSES CNC BUBUT TANPA PENDINGINAN

Turning is one of the machining operations that widely used in variety of manufacturingindustries. The quality of surface plays very important role in the performance of turningthat significantly improves fatigue strength, and corrosion resistance. It is also affectsfunctional attributes of parts such as light reflection, coating and heat treatment. Thisresearch aim to develop a mathematical model to predict surface roughness based onmachining parameter selected (spindle speed, feed, and depth of cut) with cutting coditiondry. The experiment was tested by using Trun Master TMC 320 Sinumerik 802 Smachining center. After 27 specimens were cut for experimental purposes, they weremeasured 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 was6.429 %  for training data set This showed that the statistical model could predict thesurface roughness with about 93.571 % accuracy of the testing data setKeywors: CNC Turning, Surface Roughness, Multiple Linier Regressio

RELEVANSI MATERI PEMBELAJARAN MENGGAMBAR TEKNIK SISWA KELAS XII SMK ST. MIKAEL SURAKARTA TERHADAP KEBUTUHAN DI INDUSTRI

The research’s purpose aim are to: (1)knowing the relevance of technical drawing learning materials in SMK St.Mikael Surakarta far has been to support student mastery of the technical drawing materials industrial needs, (2)knowing the relevance of technical drawing learning materials in SMK St.Mikael Surakarta to the industrial needs, (3)knowing how character education inculcated in the students graduated from vocational St.Mikael Surakarta through learning of technical drawing. This is a descriptive-qualitative research. The variables consist of technical drawing learning competencies in SMK and those in industries (independent variable). The research subject is the data obtained from schools it is SMK St. Mikael Surakarta and a number of industries. The research population and sample are a number of industries namely: PT. KING MANUFACTURE, PT. Sinar Agung Selalu Sukses, PT. SUCCESS PLASINDO. The techniques of data collection include documentation, observation, questionnaires and interviews. The steps of data analysis are data reduction or selection, data presentation, and conclusion. The analysis results in three conclusions: (1)the technical drawing learning materials of SMK St. Mi kael Surakarta students have so far been supporting the students’ mastery of competencies required by industries, (2)the technical drawing learning materials are relevant to the industrial needs, (3)by learning the technical drawing competencies, a number of students’ characters can be developed, namely honesty, thoroughness, discipline, team work and leadership. Pasword : relevance, technical drawing learning materials, industrial need

PENGARUH KECEPATAN PEMAKANAN DAN WAKTU PEMBERIAN PENDINGIN TERHADAP TINGKAT KEAUSAN CUTTER END MILL HSS HASIL PEMESINAN CNC MILLING PADA BAJA ST 40

The purpose of this research was to determine the influence of feedrate variation, timing of cooling variation, and the interaction between feedrate and timing of cooling to rate wear HSS end mill cutter in machining result CNC milling with ST 40 steel. This research is an experimental research using two factor independent variable (feedrate and timing of cooling) and one dependent variable (rate wear of HSS end mill cutter). The results data of this research described using descriptive analytic method. The results of discussion with this method was enhancement of feedrate and timing of cooling the rate wear cutter increases. Type of cutter wear that occurs is flank wear and began to grow relatively quickly then followed by a relatively slow growth to a certain cutting. The smallest edge of the cutter rate wear occurs when interaction feedrate 0.11 mm/rev with a timing of cooling 10 minutes value is 562.57 μm, while the largest edge of the cutter rate wear occurs when interaction feedrate 0.15 mm/rev with a timing of cooling 20 minutes value is 958.65 μm. This research suggests that interaction between feedrate and timing of cooling has a certain influence to rate wear of HSS end mill cutter in machining result CNC milling with ST 40 steel. Keywords: CNC milling, feedrate, timing of cooling, end mill cutter, flank wea

KARAKTERISASI TINGKAT KEKASARAN PERMUKAAN BAJA ST 40 HASIL PEMESINAN CNC MILLING ZK 7040 EFEK DARI KECEPATAN PEMAKANAN (FEED RATE) DAN AWAL WAKTU PEMBERIAN PENDINGIN

The purpose of this research was to determine the level surface roughness characterization of steel ST 40 results ZK 7040 CNC Milling machining effect feed rate and the early timing of cooling. This research was conducted at SMK WARGA Surakarta Laboratory. Machining process using ZK 7040 CNC Milling machines with control SIEMENS SINUMERIK 802S. Data obtained by measuring the level of roughness of the workpiece using a SURFCODER SE-1700 at Bahan Teknik D3, Univesitas Gadjah Mada Laboratory. This research method using descriptive analysis with independent variable were feed rates and the early timing of cooling, dependent variable was levels of surface roughness of steel ST 40. The results on the feedrate 0.11 mm / rev, 0.13 mm / rev and 0.15 mm / rev indicates that the higher the feedrate is used to produce the level of the rough workpiece roughness. In the early timing of the air 10 minutes, 15 minutes and, 20 minutes showed that the longer the first timing of cooling used in the CNC machining process Milling ZK 7040 on steel ST 40, would result in the level of the rough workpiece roughness. This research resulted in varying levels of surface roughness between N6 to N8. The level of roughness of the workpiece machining CNC Milling results ZK 7040 on steel ST 40 that the smallest on the conditions before the beginning of the cooling at feed rate 0.11 mm / rev and the early cooling time 10 minutes is equal to 1.616 μm, while the greatest rudeness occurs the feed rate of 0.15 mm / rev and the early timing of the air 20 minutes is equal to 3.603 μm. The level of roughness of the workpiece machining CNC Milling results ZK 7040 on steel ST 40 that the smallest on the conditions after the timing of cooling on CNC milling machining process ZK 7040 occurred at a feed rate of 0.11 mm / rev and the early timing of cooling after 10 minutes is equal to 1.855 μm while the roughness of the greatest place on the feed rate of 0.15 mm / rev and the early timing of cooling after 20 minutes is equal to 5.782 μm. Keywords: feed rate, early timing of air, surface roughness, steel ST 40, CNC Millin

PENGARUH KECEPATAN PEMAKANAN DAN KADAR AIR TERHADAP KEKASARAN PERMUKAAN PADA PROSES MILLING CNC 3 AXIS DENGAN MATERIAL KAYU JATI

There are many factors influencing the quality of products that are produced from wood machinery. Those influencing factors are the feedrate and moisture content.The results of this research was: (1) Reduction of feedrate of 3 axis CNC milling process with teak wood material, would be resulted the smllest surface roughness. (2) Reduction of moisture content of 3 axis CNC milling process with teak wood material, would be resulted the smallest surface roughness. (3) The surface roughness of 3 axis CNC milling processes with feedrate variation 0.2, 0.4 and 0.6 mm / rev and the moisture content 0%, 17% and 67% would be produce a level surface roughness between N7 to N11. The smallest surface roughness occurs in interaction feedrate 0.2 mm / rev with a moisture content 0% at 5.54 μm, whereas the rate of degradation surface roughness occurs interaction feedrate 0.6 mm / rev with moisture content 67% at 16.10 μm . The surface appearanceof 3 axis CNC millingproceses a fuzzy grain, loosened grains, chipped grains and chip mark. Keywords: feedrate, moisture content, CNC milling, surface roughness

ISU GENDER DALAM PROFESI PUBLIC RELATIONS DI INDONESIA

Public relations in Indonesia still often perceived as female profession and suited for women so then this profession is slow down and degradation.  Gender is became a host issues in this problem. The study of gendered issues in public relations have concducted by reseacher from the part of the world have already showed inequality gender phenomenon. This research tries to disscuss gender study in the domain of public relations in Indonesia with literarure review data collecting. The Results show that gender issues in public relations profession have to keep  monitored because it has already demonstrated discrmination gender and degrated to the public relations profession.Many parties that responded to the gender problems because of just the different perception but the development of  public relations profession also is influenced by the structure national culture, type and field of industry and bussiness needs.      Keywords: Gender, Profession, Public Relations, Jakarta, Issues &nbsp

Study of Piston Making Based on Waste Piston Material Reinforced With Stainless Steel

The use of aluminum in the automotive industry continued to increase since the year 1980, in particular aluminum alloy used for the manufacture of pistons, engine blocks, cylinder heads and valves. In this study uses the former gasoline engine piston waste recycled into the piston Daihatsu Hi-Jet 1000with the addition of ADC 12 and insert ST 60 and cast iron. Former Piston who has the composition 84.19 wt% Al, 10,7 wt% Si, plus material ADC 12 with insert stainless steel which is used as a ring groove piston with gravity casting process in the pouring temperature of 700 o C The specimens obtained from the casting material above which is a prototype of the piston with insert. The results include the test composition, microstructure, macro-and micro-hardness, shear test. The results of the most high-Si alloy composition on the composition of 25% piston former plus 75% ADC 12 and ADC 12 pure. Show the bonding of microstructure morphology best at the lowest temperature pouring with insert stainless steel that has the smallest layer interface and a good bond. Macro and micro hardness ADC 12 hardness highest on the composition of pure and pouring temperature of 700 o C with hardness 156,1 HVN and 81,4HRB. The highest shear strength of 28,50 MPa at stainless steel pouring temperature of 700 o C.

PEMETAAN KOMPETENSI-KOMPETENSI DI DUNIA KERJA BIDANG MEKANIK OTOMOTIF RODA DUA

Rencana pengembangan SMK yang dicanangkan oleh Departemen PendidikanNasional, yaitu pada tahun 2015 rasio jumlah SMK dan SMU diharapkan berubah menjadi70:30. Kebijakan ini merupakan suatu topik kajian yang cukup menarik untuk dilakukanpenelitian. Pemilihan kebijakan pengembangan SMK tersebut bukan hal yang salah tetapisaat ini dari data yang ada hanya 60% dari lulusan SMK yang dapat terserap di lapangankerja, lebih dilematis lagi ketika 60% tersebut tidak semuanya bekerja sesuai dengan jurusanyang ditekuni semasa Sekolah. Masalah ini sering dijumpai pada siswa SMK bidang keahlianOtomotif.Metode penelitian yang digunakan pada penelitian ini adalah metode penelitiankulitatif eksploratif yang bertujuan untuk menggali secara luas tentang kompetensikompetensidi dunia kerja pada bidang Otomotif.Dari hasil penelitian ini diperoleh bahwa secara garis besar kompetensi mekanikotomotif roda 2 dapat dikelompokkan menjadi 1. Kompetensi dasar mekanik, 2. Kompetensiprofesional dan 3. Kompetensi sikap. Kompetensi dasar mekanik yaitu kompetensi yangberhubungan dan menunjang dengan kompensi profesional. Kompetensi profesional yaitukompetensi utama yang berkaitan dengan profesi mekanik roda 2. Kompetensi sikap yaitukompetensi yang berhubungan dengan prilaku dan sikap kerja

Flame-Spread Behavior Of Biodiesel (B20) In A Microgravity Environment

Indonesia has implemented a policy of using diesel fuel containing 20 percent biofuel (commonly known as B20 biodiesel), as stated in Energy and Mineral Resources Ministerial Decree No. 23/2013. This study investigated the flame-spread characteristics of biodiesel (B20) in a microgravity environment through drop tower facilities. This is due to the difficulty in creating droplet sizes similar to the real liquid sprays in the combustion chamber of diesel engines. The experiment used biodiesel (B20) droplets with a diameter 1 mm. The results show that the biodiesel (B20) droplets have characteristics of a flame–spread limit distance SBC/dC0limit = 7. This paper discusses the characteristics of biodiesel (B20) droplets in detail

Optimalisasi kompetensi lulusan SMK dalam industri/teknologi terapan

Kebijakan yang relevan dan baik selalu ditopang oleh suatu kajian yang baik pula. Artinya selalu ada korelasi positif antara suatu kajian yang berbasis penelitian akademik dengan kebijakan apa yang diambil. Tentu dalam konteks ini adalah yang ada kaitannya dengan pengembangan SMK ke depannya. Kajian NSPK ini bertujuan tidak lain untuk menjawab hal tersebut. Tuntutan pembaharuan kebijakan ditengah arus dan gelombang modernisasi yang semakin dinamis sangat diperlukan terlebih perkembangan revolusi Industri sudah mencapai 4.0 yang berbasis cyber physical system ini. Revolusi industrisangat memiliki keterkaitan dengan Sekolah Menengah Kejuruan salah satunya pada aspek penggunaan peralatan praktik sebagai penunjang kompetensi siswa. Inti dari praktik siswa adalah memberikan kemampuan practical dalam penguasaan penggunaan peralatan praktik, semakin alat yang dimiliki relevan dengan perkembangan zaman semakin membantu pula peserta didik dalam upgrading skill-nya