Subjective hearing sensation of process variations at a milling machine. How reliable will chatter marks be detected?

2021 ◽  
Vol 263 (2) ◽  
pp. 4088-4099
Author(s):  
Florian Trautmann ◽  
Björn Knöfel ◽  
Welf-Guntram Drossel ◽  
Jan Troge ◽  
Markus Freund ◽  
...  
Keyword(s):  
Process Variations ◽  
Rotation Frequency ◽  
Machining Process ◽  
Sensor Data ◽  
Milling Machine ◽  
Acceleration Sensors ◽  
Machine Operators ◽  
Machining Vibrations ◽  
Tool Diameter ◽  
Chatter Marks

Intuition enables experienced machine operators to detect production errors and to identify their specific sources. A prominent example in machining are chatter marks caused by machining vibrations. The operator's assessment, if the process runs stable or not, is not exclusively based on technical parameters such as rotation frequency, tool diameter, or the number of teeth. Because the human ear is a powerful feature extraction and classification device, this study investigates to what degree the hearing sensation influences the operators decision making. A steel machining process with a design of experiments (DOE)-based variation of process parameters was conducted on a milling machine. Microphone and acceleration sensors recorded machining vibrations and machine operators documented their hearing sensation via survey sheet. In order to obtain the optimal dataset for calculating various psychoacoustic characteristics, a principle component analysis was conducted. The subsequent correlation analysis of all sensor data and the operator information suggest that psychoacoustic characteristics such as tonality and loudness are very good indicators of the process quality perceived by the operator. The results support the application of psychoacoustic technology for machine and process monitoring.

Optimizing the Machining Parameters in Glass Grinding Operation on the CNC Milling Machine for Best Surface Roughness

2010 ◽  
Vol 154-155 ◽  
pp. 721-726 ◽  
Author(s):  
Mohd Sayuti ◽  
Ahmed Aly Diaa Mohammed Sarhan ◽  
Mohd Hamdi Bin Abd Shukor
Keyword(s):  
Surface Roughness ◽  
Machining Process ◽  
Depth Of Cut ◽  
Response Analysis ◽  
Machining Parameters ◽  
Milling Machine ◽  
Cnc Milling ◽  
Cnc Machine ◽  
Cnc Milling Machine ◽  
Tool Diameter

Glass is one of the most difficult materials to be machined due to its brittle nature and unique structure such that the fracture is often occurred during machining and the surface finish produced is often poor. CNC milling machine is possible to be used with several parameters making the machining process on the glass special compared to other machining process. However, the application of grinding process on the CNC milling machine would be an ideal solution in generating special products with good surface roughness. This paper studies how to optimize the different machining parameters in glass grinding operation on CNC machine seeking for best surface roughness. These parameters include the spindle speed, feed rate, depth of cut, lubrication mode, tool type, tool diameter and tool wear. To optimize these machining parameters in which the most significant parameters affecting the surface roughness can be identified, Taguchi optimization method is used with the orthogonal array of L8(26). However, to obtain the most optimum parameters for best surface roughness, the signal to noise (S/N) response analysis and Pareto analysis of variance (ANOVA) methods are implemented. Finally, the confirmation test is carried out to investigate the improvement of the optimization. The results showed an improvement of 8.91 % in the measured surface roughness.

3D-to-2D Mapping of Cutter Paths in NC Programming of Complex Engineering Parts

1993 ◽  
Author(s):  
Chao-Hwa Chang
Keyword(s):  
Three Dimensional ◽  
Machining Process ◽  
Milling Machine ◽  
Systematic Method ◽  
Nc Programming ◽  
Cutter Path ◽  
Nc Milling ◽  
Complex Engineering ◽  
High Level ◽  
Mapping Concept

Abstract The concept of mapping a three dimensional (3D) contouring cutter path with major motion in a plane parallel to the Z axis onto the X-Y plane or one perpendicular to the Z axis is introduced. A systematic method is developed that can be used to program, in APT or other high-level languages, complex contouring cutter motion based on the concept introduced. As a result, NC programming of contouring motion for many complex engineering parts on a 3-axis numerically controlled (NC) milling machine, which is often considered difficult, can be greatly simplified. Part examples are discussed; and the APT programs defining the cutter path based on the 3D-to-2D mapping concept, are also analyzed in detail. The concept and method introduced proved to be a powerful tool for programming the NC machining process for many parts, particularly dies and molds.

Effect of process parameters on formability in two-point incremental forming-machining of planar and twisted AA5083 blades

2022 ◽  
pp. 095440542110697
Author(s):  
Hossein Ghorbani-Menghari ◽  
Mehrdad Azadipour ◽  
Mehran Ghasempour-Mouziraji ◽  
Young Hoon Moon ◽  
Ji Hoon Kim
Keyword(s):  
Tool Path ◽  
Incremental Forming ◽  
Dimensional Accuracy ◽  
Numerical Control ◽  
Machining Process ◽  
Curved Surface ◽  
Forming Process ◽  
Forming Temperature ◽  
Feature Based ◽  
Tool Diameter

The deformation machining process (DMP) involves machining and incremental forming of thin structures. It can be applied for manufacturing products such as curved-surface blades without using 5-axis computerised numerical control machines. This work presents the effect of tool diameter and forming temperature on spring-back and dimensional accuracy of a simple fabricated part. The results of the first phase of the study are utilised to design the fabrication process of a curved surface blade. A feature-based algorithm is used to design the tool path for the forming process. The dimensional accuracy of the final product is improved through warm forming, two-point incremental forming, and extension of the bending zone to the outside of the product edges. The results show that DMP can be used to fabricate complex curved-surface workpieces with acceptable dimensional accuracy.

Finite Element Analysis of Incremental Sheet Forming for Metal Sheet

2018 ◽  
Vol 783 ◽  
pp. 148-153
Author(s):  
Muhammad Sajjad ◽  
Jithin Ambarayil Joy ◽  
Dong Won Jung
Keyword(s):  
Mechanical Properties ◽  
Sheet Metal ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Machining Process ◽  
Machining Parameters ◽  
Forming Process ◽  
Element Analysis ◽  
Tool Diameter

Incremental sheet metal forming, is a non-conventional machining process which offers higher formability, flexibility and low cost of production than the traditional conventional forming process. Punch or tool used in this forming process consecutively forces the sheet to deform locally and ultimately gives the target profile. Various machining parameters, such as type of tool, tool path, tool size, feed rate and mechanical properties of sheet metal, like strength co-efficient, strain hardening index and ultimate tensile strength, effects the forming process and the formability of final product. In this research paper, Single Point Incremental Forming was simulated using Dassault system’s Abaqus 6.12-1 and results are obtained. Results of sheet profile and there change in thickness is investigated. For this paper, we simulated the process in abaqus. The tool diameter and rotational speed is find out for the production of parts through incremental forming. The simulation is done for two type of material with different mechanical properties. Various research papers were used to understand the process of incremental forming and its simulation.

Mathematical Approach for Geometric Error Modeling of Three Axis CNC Vertical Milling Machine

2016 ◽  
Vol 842 ◽  
pp. 303-310 ◽  
Author(s):  
Widyanti Kwintarini ◽  
Agung Wibowo ◽  
Yatna Yuwana Martawirya
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Milling Machine ◽  
Cnc Machine ◽  
Geometrical Errors ◽  
Vertical Milling ◽  
Vertical Milling Machine ◽  
Accuracy And Repeatability

The aim of this paper overviews about to find out the errors that come from three axis CNC vertical milling machine. The errors come from, the CNC milling machine can be modelled into mathematical models and later on these error models will be used to analyse the errors in the measured data. Many errors from CNC machine tools have given significant effects toward the accuracy and repeatability of manufacturing process. There are two error sources come from CNC machine tools such as tool deflection and thermal distortions of machine tool structure. These errors later on will contribute to result in the geometrical deviations of moving axis in CNC vertical milling machine. Geometrical deviations of moving axis such as linear positioning errors, roll, pitch and yaw can be designated as volumetric errors in three axis machine tool. Geometrical deviations of moving axises happen at every axis in three axis CNC vertical milling machine. Geometrical deviations of moving axises in linear and angular movement has the amount of errors up to twenty one errors. Moreover, this geometrical errors play the major role in the total amount of errors and for that particular reason extra attention towards the geometrical deviation errors will be needed along machining process. Each of geometrical error of three axes vertical machining center is modeled using a homogeneous transformation matrix (HTM). The developed mathematical model is used to calculate geometrical errors at each axis and to predict the resultant error vector at the interface of machine tool and workpiece for error compensation.

Integration of Vibration Absorbers in Milling Chucks

2019 ◽  
Author(s):  
Mihir Joshi ◽  
Matthias Weigold ◽  
Michael Schoell
Keyword(s):  
Cutting Tool ◽  
Slenderness Ratio ◽  
Dynamic Compliance ◽  
Engineering Industry ◽  
Machining Process ◽  
Vibration Absorber ◽  
Machining Processes ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Machining Vibrations

Abstract The use of cutting tool systems with a high slenderness ratio is encountered in the machining of deep cavities in the mechanical engineering industry, especially in the manufacturing of tools and dies. Cutting tool systems with a large slenderness ratio, owing to their dynamic compliance, are prone to vibrations during machining processes. These vibrations affect the quality of the machining process and the life of machine components. Integration of a vibration absorber in the cutting tool system helps in the reduction of machining vibrations. The reduction in vibrations is due to a shift in the resonance frequency of the modified system. This experimental study presents the identification of design possibilities of a vibration absorber for integration in the cutting tool system. The mass and geometry of the vibration absorber are varied and its integration in the milling chuck is explored. Firstly, experimental modal analysis is conducted to determine the effects of the dynamic vibration absorber on the frequency response function of the modified cutting tool system. Secondly, the effects of the dynamic vibration absorber on the machining process for a range of technology parameters are illustrated. During the machining process, the cutting forces are measured using a three-component dynamometer in time domain. Finally, the results are evaluated based on process quality, i.e. surface roughness and analysis of cutting force signal in the frequency domain. This study provides an understanding of the relationship between the mass and the geometry of the vibration absorber integrated in the cutting tool system and their influence on process stability.

Research of the Nonlinear 3D Surface NC Machining Technology

2012 ◽  
Vol 538-541 ◽  
pp. 190-195
Author(s):  
Hong Jun Liu ◽  
Jie Huang ◽  
Shu Ya Zhi
Keyword(s):  
Surface Finish ◽  
Machining Process ◽  
Production Cycle ◽  
Milling Machine ◽  
Post Processing ◽  
Technical Problems ◽  
Process Plan ◽  
Surface Machining ◽  
Machining Precision ◽  
Cad Cam

Discuss a way of using the CAD/ CAM technology to process nonlinear space surface. By analyzing the processing of nonlinear space surface, the nonlinear space surface machining process plan was determined. The fine model and program was finished by innovative using of combination modeling method in UG. Many key technical problems such as surface finish, work fixture were solved in the process of dealing with CAD/CAM of nonlinear space surface, acceptable product was made on common milling machine by using post-processing NC coding,. The process plan improved machining precision and shortened the production cycle，a good results have been obtained.

scholarly journals Study on the Gap Flow Simulation in EDM Small Hole Machining with Ti Alloy

2017 ◽  
Vol 2017 ◽  
pp. 1-23 ◽  
Author(s):  
Shengfang Zhang ◽  
Wenchao Zhang ◽  
Yu Liu ◽  
Fujian Ma ◽  
Chong Su ◽  
...  
Keyword(s):  
Electrical Discharge Machining ◽  
Small Hole ◽  
Machining Process ◽  
3D Simulation ◽  
Ti Alloy ◽  
Gap Flow ◽  
Tool Diameter ◽  
Hole Machining ◽  
Edm Process ◽  
Self Adaptive

In electrical discharge machining (EDM) process, the debris removed from electrode material strongly affects the machining efficiency and accuracy, especially for the deep small hole machining process. In case of Ti alloy, the debris movement and removal process in gap flow between electrodes for small hole EDM process is studied in this paper. Based on the solid-liquid two-phase flow equation, the mathematical model on the gap flow field with flushing and self-adaptive disturbation is developed. In our 3D simulation process, the count of debris increases with number of EDM discharge cycles, and the disturbation generated by the movement of self-adaptive tool in the gap flow is considered. The methods of smoothing and remeshing are also applied in the modeling process to enable a movable tool. Under different depth, flushing velocity, and tool diameter, the distribution of velocity field, pressure field of gap flow, and debris movement are analyzed. The statistical study of debris distribution under different machining conditions is also carried out. Finally, a series of experiments are conducted on a self-made machine to verify the 3D simulation model. The experiment results show the burn mark at hole bottom and the tapered wall, which corresponds well with the simulating conclusion.

scholarly journals A Hybrid Approach for Noise Reduction in Acoustic Signal of Machining Process Using Neural Networks and ARMA Model

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8023
Author(s):  
Tayyab Zafar ◽  
Khurram Kamal ◽  
Senthan Mathavan ◽  
Ghulam Hussain ◽  
Mohammed Alkahtani ◽  
...  
Keyword(s):  
Neural Network ◽  
Background Noise ◽  
Manufacturing Systems ◽  
Signal Reconstruction ◽  
Research Work ◽  
Hybrid Approach ◽  
Arma Model ◽  
Machining Process ◽  
Depth Of Cut ◽  
Milling Machine

Intelligent machining has become an important part of manufacturing systems because of the increased demand for productivity. Tool condition monitoring is an integral part of these systems. Airborne acoustic emission from the machining process is a vital indicator of tool health, however, it is highly affected by background noise. Reducing the background noise helps in developing a low-cost system. In this research work, a feedforward neural network is used as an adaptive filter to reduce the background noise. Acoustic signals from four different machines in the background are acquired and are introduced to a machining signal at different speeds and feed-rates at a constant depth of cut. These four machines are a three-axis milling machine, a four-axis mini-milling machine, a variable speed DC motor, and a grinding machine. The backpropagation neural network shows an accuracy of 75.82% in classifying the background noise. To reconstruct the filtered signal, a novel autoregressive moving average (ARMA)-based algorithm is proposed. An average increase of 71.3% in signal-to-noise ratio (SNR) is found before and after signal reconstruction. The proposed technique shows promising results for signal reconstruction for the machining process.

scholarly journals OPTIMASI PARAMETER PERMESINAN TERHADAP WAKTU PROSES PADA PEMROGRAMAN CNC MILLING DENGAN BERBASIS CAD/CAM

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
I G.N.K. Yudhyadi ◽  
Tri Rachmanto ◽  
Adnan Dedy Ramadan
Keyword(s):  
Cutting Speed ◽  
Operation Time ◽  
Milling Process ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Milling Machine ◽  
Cnc Milling ◽  
Cnc Milling Machine ◽  
Machining Parameter

Milling process is one of many machining processes for manufacturing component. The length of time in the process of milling machining is influenced by selection and design of machining parameters including cutting speed, feedrate and depth of cut. The purpose of this study to know the influence of cutting speed, feedrate and depth of cut as independent variables versus operation time at CNC milling process as dependent variables. Each independent variable consists of three level of factors; low, medium and high.Time machining process is measured from operation time simulation program, feed cut length and rapid traverse length. The results of statistically from software simulation MasterCam X Milling, then do comparison to CNC Milling machine.  The data from experiments was statistical analyzed by Anova and Regression methods by software minitab 16.Results show that the greater feedrate and depth of cut shorten the operation time of machinery, whereas cutting speed is not significant influence. Depth of cut has the most highly contribution with the value of 49.56%, followed by feedrate 43% and cutting speed 0.92%. Optimal time of machining process total is 71.92 minutes, with machining parameter on the condition cutting speed is 75360 mm/minutes, feedrate is 800 mm/minutes and depth of cut = 1 mm. Results of comparison time machining process in software Mastercam X milling with CNC Milling machine indicates there is difference not significant with the value of 0,35%.

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