KARAKTERISTIK DINAMIK COMPUTER NUMERICAL CONTROL MILLING ROUTER 4 AXIS

Penelitian ini dilakukan untuk mengetahui karakteristik dinamik Computer Numerical Control Router 4 Axis dengan menggunakan metode Bump Test. Pengujian dilakukan dengan cara menempatkan sensor Accelerometer Khoctek 107b pada Mesin CNC Router 4 Axis pada sumbu x, y, z dikerangka atas, kerangka bawah, dan spindle. Hasil eksperimen pengujian getaran Mesin CNC dibagi kedalam dua proses pengujian yaitu kondisi normal dan kondisi rusak pada masing-masing sumbu. Diperoleh bahwa pengujian ini menghasilkan frekuensi global dimana frekuensi 8 Hz, 24 Hz, dan 40 Hz muncul disetiap sumbu x, y, dan z pada kerangka atas, kerangka bawah dan spindle. Pada mesin dengan kondisi rusak muncul frekuensi lokal pada sumbu y kerangka atas sebesar 5 Hz. Kemudian pada sumbu y spindle muncul frekuensi lokal sebesar 10 Hz, 56 Hz, dan 88 Hz. Munculnya frekuensi lokal menandakan adanya kerusakan pada CNC oleh sumbu tertentu selain frekuensi global.

Examine the optimal position of controls and display in computer numerical control machines

In Engineering Industries suffering due to industrial wound and ill health, of the Computer Numerical Control machines operators are in the increasing trend, in the subjective analysis which we carried out for the CNC machine, the operators expressing the discomfort at the neck, upper back, lower back, shoulder, and arm because of working with the keys in the controls and viewing the display. The aim of this examination is to identify the most favourable location of control and display through various muscles that activate while performing in CNC machine operations. We introduce surface Electromyogram (EMG) to determine the muscle activity and deliberate on plane of the body close to respective muscles of an operator.The muscle activity measured for all the twenty subjects, at five different levels to find out the best optimal location for controls and display to establish the findings of the subjective study. Though there is no clear trend when all the subjects are aggregated, it is seen that 90 cm-100 cm be the optimum range for the midpoint of the control panel and 143cm-148 cm appears to be the optimum range for the midpoint of the display. Since changes in muscle activity are comparatively small for all the six muscles taken for study, however, the effect of cumulative activity borne over a shift, week, month, and year are to be considered. Muscle activity may increase in repetitive head/finger movements. These combined effects are to be captured for the ergonomic design of the CNC operator interface.

A study of using back-propagation neural model in automatic lubrication installation for the feeding system of computer numerical control machine tool

Nowadays, the feeding systems of computer numerical control machine tools are lubricated by periodic oil supply or fixed stroke, the lubrication is insufficient in the case of high load and high-speed movement, and the lubrication is excessive during finishing and low feed rate. This study discusses the optimum lubrication timing of the feeding system. When the feeding system is moving, the servomotor torque value and current, accuracy, and oil film thickness are measured by sensors. Moreover, the lubrication characteristic model is validated and built by using the sensor values, and the optimal lubrication state estimation is obtained by using the back-propagation neural model. Then analyzed and feedback to the machine tool controller, to intelligent the lubrication system. According to the test, when the feed rate is increased by 5 m/min, the friction coefficient increases with rate, increasing the output of the frictional value of the work table by 6.90%. When the load is increased by 175 kg, the friction coefficient decreases with load, reducing the frictional value output of table movement by 6.71%. In the relationship between oil film thickness and current, the accuracy difference between the prediction and actual test results is less than 10%; in the case of the same accuracy, the oil supply frequency is reduced by 80%, and environmentally friendly machine tool has been achieved.

Rancang bangun mesin CNC laser cutting CO2 2 axis bebasis microcontroler dengan softwere Mach3

Teknologi laser saat ini sudah sedemikian pesat dan digunakan hampir disegala bidang, seperti dibidang manufaktur, medis, seni, transaksi perdagangan dan percetakan. Walaupun ada berbagai jenis laser yang ada dipasaran, namun dibidang manufaktur yang seringkali dijumpai adalah Laser C02. Hal ini disebabkan dayanya yang relatif besar sehingga pemanfaatannya lebih fleksibel dapat digunakan untuk pemotongan pada material lembaran tipis maupun pada material yang agak tebal. Laser cutting memiliki berbagai keunggulan dibandingkan teknologi manufaktur lainnya karena dapat menerima data langsung dari komputer, sehingga otomatisasi pemotongan dapat berjalan pada dunia industri. Penggunaan mesin CNC (Computer Numerical Control) pada sistem laser cutting sangat diperlukan, karena kita bisa memotong suatu bahan dengan bentuk desain sesuai yang kita inginkan dan dengan kualitas pemotongan yang bagus. Metode yang digunakan adalah eksperimental dengan merancang dan membuat serta menguji mesin CNC laser cutting CO2. Pengujian dilakukan dengan mencari feedrate yang terbaik dan Mengetahui tingkat akurasi hasil pemotongan pada jenis alur pemotongan yang berbeda. Dari hasil penelitian dapat disimpulkan bahwa feedrate yang terbaik adalah 50 (mm/menit), dan juga tingkat akurasi dengan bentuk pemotongan alur yang berbeda mempengaruhi pada tingkat keakurasian pemotongan, koefisien akurasi terendah pada bentuk lingkaran 0,73 (mm).

Predictive maintenance for rotating machinery by using vibration analysis

This paper presents a complete and well tested virtual instrument (VI) for computer numerical control (CNC) machine predictive maintenance. The national instrument (NI) hardware, LabVIEW software and accelerometer sensor are acquired for the vibration analysis integrated with virtual instrument were developed based on the vibration severity chart threshold in ISO 10816. Validation experiments of the predictive maintenance module were utilized on drilling and milling processes to test and verify the effectiveness of the module. Results obtained from current module can monitor and provide the machine conditions at different condition of good, satisfactory, unsatisfactory, and unacceptable for rotating machinery status according to the vibration severity chart as per ISO 10816.