Experimental analysis of deep slot milling in EN AW 2024-T3 alloy by stretched trochoidal toolpath and variable helix angle tool

2021 ◽  
Vol 35 ◽  
pp. 346-360
Author(s):  
O. Rodriguez-Alabanda ◽  
G. Guerrero-Vaca ◽  
E. Molero ◽  
P.E. Romero
Keyword(s):  
Experimental Analysis ◽  
Helix Angle ◽  
Slot Milling ◽  
Variable Helix

scholarly journals Pengaruh Geometri Pahat Variabel Helix Angle Pada Parameter Mesin Cnc Milling Vertikal Berbasis Mikrokontroler Terhadap Nilai Getaran Chatter

2020 ◽  
Vol 1 (2) ◽  
pp. 62-71
Author(s):  
Festo Andre Hardinsi ◽  
Oyong Novareza ◽  
Achmad As’ad Sonief
Keyword(s):  
Feed Rate ◽  
Helix Angle ◽  
Machining Process ◽  
Depth Of Cut ◽  
Cnc Milling ◽  
Chatter Vibration ◽  
Vibration Acceleration ◽  
Slot Milling ◽  
Excited Vibration ◽  
Variable Helix

Abstrak Objektif. Getaran yang sering terjadi pada pengerjaan proses produksi menggunakan permesinan CNC milling merupakan hal yang sangat penting untuk diperhitungkan. Getaran ini dapat menyebabkan perubahan dimensi dan mempengaruhi tingkat kualitas benda kerja yang dihasilkan, sehingga efek getaran chatter atau self-excited vibration  pada proses pengerjaan produksi menjadi masalah utama dalam proses permesinan milling. Nilai getaran chatter ditentukan menggunakan grafik SLD secara ekperimental untuk mengetahui batas antara chatter free dan chatter occurs. Material and Metode. Material yang digunakan dalam penelitian ini adalah Stanless steel 304, dengan menggunakan sensor MPU 6050 yang terhubung pada mikrokontroler Arduino Uno menggunakan software LabVIEW 2019 student edition yang digunakan untuk mengidentifikasi nilai acceleration getaran chatter. Besar nilai acceleration diukur menggunakan FFT menggunakan software DIAdem 2019 student. Metode yang digunakan dalam penelitian ini adalah dalam bentuk eksperimental, dengan geometri pahat Variabel Helix Angle (VHA) 2 variasi sudut yaitu 40/42 (Derajat), Spindel Speed sebesar 2000,2500,3000 (RPM) , Axial Depth Of Cut sebesar 0.5, 1.0, 1.5 (mm), dan Feed Rate sebesar 100, 125 dan 150 (mm/s). Hasil. Hasil pada Grafik Stability Lobe Diagram yang didapatkan pada proses permesinan slot milling menggunakan pahat variable helix angle 40/42 derajat dengan feed rate 150 mm/mnt memiliki  chatter free yang lebih tinggi dibandingkan dengan feed rate 100 dan 125 mm/mnt. Kesimpulan.  Dari hasil yang didapatkan bahwa semakin tinggi nilai feed rate maka nilai acceleration getaran chatter semakin rendah. Untuk pengembangan dalam penelitian selanjutkan maka perlu dilakukan pemilihan parameter geometri pahat dengan variasi 3 sudut mata pahat untuk mengetahui nilai getaran chatter yang signifikan. Abstrack Objective.Vibration that often occurs in the production process using CNC milling is very important to be taken into account. This is vibration can cause dimensional changes and affect the level of quality of the workpiece produced. Therefore, effect of chatter vibration or self-excited vibration on production process becomes a major problem in the milling machining process. Chatter vibration values ​​can be determined using experimental SLD for determine boundary between free chatter and chatter occur. Materials and Methods .The material used in this study is stanless steel 304, using the MPU 6050 sensor connected to Arduino Uno mikrokontroler using LabVIEW 2019 student edition software that is used to identify chatter vibration acceleration. Acceleration is measured using FFT using  2019 student DIAdem software. The method used is experimental, geometry Variable Helix Angle 2 angular 40/42 (Degrees), Spindel Speed ​​of 2000,2500,3000 (RPM), Axial Depth Of Cut of 0.5, 1.0, 1.5 (mm), and Feed Rate of 100, 125 and 150 (mm / s). Results. Results in the Graph Lobe Stability Diagram obtained in  slot milling machining process using a variable helix angle of 40/42 degrees with  feed rate of 150 mm / min have higher chatter free compared to feed rates of 100 and 125 mm / min. Conclusion. The results show that  higher the value of  feed rate, chatter vibration acceleration value is lower. For further development in research, it is necessary to select  tool geometry parameters with variations of 3 tool eye angle to determine  chatter vibration significant

Stability prediction of milling process with variable pitch and variable helix cutters

2013 ◽  
Vol 228 (2) ◽  
pp. 281-293 ◽  
Author(s):  
Gang Jin ◽  
Qichang Zhang ◽  
Shuying Hao ◽  
Qizhi Xie
Keyword(s):  
Helix Angle ◽  
Milling Process ◽  
Force Model ◽  
Stability Prediction ◽  
Chatter Vibration ◽  
Variable Pitch ◽  
Tool Geometries ◽  
Variable Helix ◽  
Piecewise Continuous ◽  
The Stability

The use of variable pitch or helix cutters is a known means to prevent chatter vibration during milling. In this article, an alternative method based on an improved semi-discretization method is proposed to predict the stability of variable pitch or variable helix milling. In order to consider the effect of distributed system delays attributed to helix variation, the average delays were calculated for each flute after the engaged cutting flutes were divided into a finite number of axial elements. Meanwhile, a straightforward integral force model, which can consider the piecewise continuous regions of the cutting that describe the helix angle is used to determine the cutting force. Through comparisons with prior works, time-domain simulations, and cutting tests, the proposed approach was verified. In addition, the method was applied to examine the effect of tool geometries on stability trends. Several phenomena for certain combinations of pitch and helix angles are shown and explained.

The Fluid-Structure Interaction Analysis of the Inverted Umbrella Aerator Curved Blade

2014 ◽  
Vol 705 ◽  
pp. 101-105 ◽  
Author(s):  
Pu Xing ◽  
Ai Min Zhang ◽  
Zhi Xiong Deng
Keyword(s):  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Logarithmic Spiral ◽  
Helix Angle ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Variable Helix ◽  
Curved Blade ◽  
New Type ◽  
Spiral Line

The blades are important components of the inverted umbrella aerators. In this paper, the inverted umbrella aerator blade with curved surface, which was arranged according to the variable helix angle of logarithmic spiral line, was designed and simulated. Through the simulation and calculation of the flow field of oxidation ditch that pushed by the blade, based on the fluid-structure interaction analysis, the reliability of the impeller blades has been studied. All the results showing that the new type inverted umbrella surface aerator blade is reliable.

scholarly journals Research on Centroid Distribution and Dynamic Characteristics of Irregular Tooth End Milling Cutters

2021 ◽  
Vol 11 (21) ◽  
pp. 10071
Author(s):  
Haibin Yu ◽  
Minli Zheng ◽  
Wei Zhang ◽  
Wenrui Lv ◽  
Wanying Nie
Keyword(s):  
Dynamic Characteristics ◽  
Structural Design ◽  
Vibration Mode ◽  
End Milling ◽  
Dynamic Performance ◽  
Helix Angle ◽  
Element Analysis ◽  
Milling Cutter ◽  
Dynamic Excitation ◽  
Variable Helix

For irregular end milling cutters, the incomplete equality of the pitch angle and helix angle will lead to an uneven mass distribution. The problems of centroid distribution caused by this, and whether it would affect the dynamic characteristics of milling cutters, have not been systematically studied. In this paper, through the proposed mathematical model, the centroid positions of each radial section of four types of end milling cutters, with equal overall eccentricities and different structures, are calculated, respectively. The centroid distribution of end milling cutters is studied and analyzed. Combined with finite element analysis, the vibration mode, frequency, and resonance frequency band of each type of end milling cutter, under the same dynamic excitation, is obtained. Based on a study of the dynamic characteristics of various types of end milling cutters, it is found that the response displacement of the variable pitch variable helix end milling cutter is the smallest, which is 0.043800 mm. With the same level of accuracy, its dynamic performance is the best. On the premise of not changing the overall eccentricity of the end milling cutter, a new idea for the structural design to improve the dynamic characteristics of the end milling cutter is provided.

The Importance of Including Size Effect When Modeling Slot Milling

1998 ◽  
Vol 120 (1) ◽  
pp. 68-75 ◽  
Author(s):  
S. N. Melkote ◽  
W. J. Endres
Keyword(s):  
Size Effect ◽  
Cutting Force ◽  
End Milling ◽  
Helix Angle ◽  
Milling Process ◽  
Depth Of Cut ◽  
Slot Milling ◽  
Milling Operations ◽  
Force Variation ◽  
Axial Depth

This paper presents a detailed mechanistic force analysis that includes size effect for slot milling operations. Existing studies of the milling process have modeled the slot end milling operation as a simple geometric extension of peripheral end milling models with constant values for the specific energies used to predict forces for a given cutter geometry and cutting conditions. This paper addresses the limitations of this approach for accurate predictions of the instantaneous cutting force variation, particularly for steady-state slotting with four-flute cutters. It is shown through a comparison of model simulations and experimental results that significantly improved predictions of the cutting force variation are obtained by properly accounting for the size effect in slotting. The dependence of the cutting force variation on axial depth of cut and helix angle is demonstrated. Practical implications of selecting helix angle and axial depth of cut based on the improved slot end milling model are also discussed. Modeling approaches other than the mechanistic approach considered here are also noted in this light.

scholarly journals OPTIMIZATION OF VARIABEL HELIX ANGLE PARAMETERS IN CNC MILLING OF CHATTER AND SURFACE ROUGHNES USING TAGUCHI METHOD

2021 ◽  
Vol 9 (1) ◽  
pp. 35-44
Author(s):  
Festo Andre Hardinsi ◽  
◽  
Oyong Novareza ◽  
Achmad As'ad Sonief
Keyword(s):  
Surface Roughness ◽  
Taguchi Method ◽  
Feed Rate ◽  
Helix Angle ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Cnc Milling ◽  
Excited Vibration ◽  
Optimal Value ◽  
Variable Helix

In the manufacturing industries, the main problem in process of operating CNC milling machine was chatter effect (self-excited vibration) which increases the quality of the surface roughness. In this study is to determine optimal value of parameters for chatter and surface roughness. The chatter measured using accelerometer MPU-6050 with Arduino by software LabVIEW-2019 based on peaks-FFT value and the surface roughness measured by SJ-301 tester. The research parameters like variable helix angle, spindle speed, feed rate, and depth of cut using stainless steel 304 by Taguchi method. The optimum parameters value obtained are variable helix 35/38 degrees, spindle speed 3000 RPM, feed rate 150 mm/min and depth of cut 0.4 mm. Based on ANOVA value, the variable helix angle and depth of cut are found to be significant for chatter and surface roughness. The depth of cut was high contribution by ANOVA chatter by 93.84% and surface roughness by 91.93%.

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