End Milling of Elastomers—Fixture Design and Tool Effectiveness for Material Removal

2004 ◽  
Vol 126 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Albert J. Shih ◽  
Mark A. Lewis ◽  
John S. Strenkowski
Keyword(s):  
End Milling ◽  
Fixture Design ◽  
Tool Selection ◽  
Solid Carbon Dioxide ◽  
Machined Surface ◽  
Geometric Configurations ◽  
Lack Of Information ◽  
Low Elastic Modulus ◽  
Element Technique ◽  
Part Fixturing

This paper describes the machining of elastomers using sharp, woodworking tools and the machining of cryogenically cooled elastomers. Due to the lack of information on tool selection for elastomer machining, a set of thirteen tools that cover different sizes and tool geometries and materials was used in this study. Fixture design was found to be critical in machining of elastomers because of its relatively low elastic modulus. The cutting force created during machining can generate significant deformations in the elastomer workpiece. The finite element technique is used to analyze the structural stiffness of the elastomer workpiece under different geometric configurations. The effective stiffness is defined to quantify and compare the stiffness of elastomer workpiece machined by different tool sizes. The cleanliness of the groove machined by end milling is investigated. Use of some down-cut end-milling tools effectively removed the elastomer material at room temperature and generated a clean groove. The tool configuration and part fixturing are identified as the two most important variables that affect the cleanliness of machined grooves. Cooling the elastomer workpiece by solid carbon dioxide (dry ice) to about −78.6°C improved the machined surface finish.

scholarly journals Fabrication and characterization of resistive double square loop arrays for ultra-wide bandwidth microwave absorption

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji-Young Jeong ◽  
Je-Ryung Lee ◽  
Hyeonjin Park ◽  
Joonkyo Jung ◽  
Doo-Sun Choi ◽  
...  
Keyword(s):  
Sheet Resistance ◽  
Manufacturing Process ◽  
End Milling ◽  
Milling Process ◽  
Wide Bandwidth ◽  
Machined Surface ◽  
Array Pattern ◽  
Micro End Milling ◽  
Array Structures ◽  
Printing Processes

AbstractMicrowave absorbers using conductive ink are generally fabricated by printing an array pattern on a substrate to generate electromagnetic fields. However, screen printing processes are difficult to vary the sheet resistance values for different regions of the pattern on the same layer, because the printing process deposits materials at the same height over the entire surface of substrate. In this study, a promising manufacturing process was suggested for engraved resistive double square loop arrays with ultra-wide bandwidth microwave. The developed manufacturing process consists of a micro-end-milling, inking, and planing processes. A 144-number of double square loop array was precisely machined on a polymethyl methacrylate workpiece with the micro-end-milling process. After engraving array structures, the machined surface was completely covered with the developed conductive carbon ink with a sheet resistance of 15 Ω/sq. It was cured at room temperature. Excluding the ink that filled the machined double square loop array, overflowed ink was removed with the planing process to achieve full filled and isolated resistive array patterns. The fabricated microwave absorber showed a small radar cross-section with reflectance less than − 10 dB in the frequency band range of 8.0–14.6 GHz.

Surface Roughness Identification in End Milling Using Vibration Signals and Fuzzy Clustering

2016 ◽  
Author(s):  
Issam Abu-Mahfouz ◽  
Amit Banerjee ◽  
A. H. M. Esfakur Rahman
Keyword(s):  
Surface Roughness ◽  
Fuzzy Clustering ◽  
Wavelet Transforms ◽  
Fourier Transforms ◽  
End Milling ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Machined Surface ◽  
Vibration Signals

The study presented involves the identification of surface roughness in Aluminum work pieces in an end milling process using fuzzy clustering of vibration signals. Vibration signals are experimentally acquired using an accelerometer for varying cutting conditions such as spindle speed, feed rate and depth of cut. Features are then extracted by processing the acquired signals in both the time and frequency domain. Techniques based on statistical parameters, Fast Fourier Transforms (FFT) and the Continuous Wavelet Transforms (CWT) are utilized for feature extraction. The surface roughness of the machined surface is also measured. In this study, fuzzy clustering is used to partition the feature sets, followed by a correlation with the experimentally obtained surface roughness measurements. The fuzzifier and the number of clusters are varied and it is found that the partitions produced by fuzzy clustering in the vibration signal feature space are related to the partitions based on cutting conditions with surface roughness as the output parameter. The results based on limited simulations are encouraging and work is underway to develop a larger framework for online cutting condition monitoring system for end milling.

Analysis of Cutting Forces and Machining Error in Ball End Milling of Cylindrical Surfaces

2011 ◽  
Vol 328-330 ◽  
pp. 560-564
Author(s):  
Ba Sheng Ouyang ◽  
Guo Xiang Lin ◽  
Yong Hui Tang
Keyword(s):  
Cutting Forces ◽  
End Milling ◽  
Cutting Conditions ◽  
Machining Error ◽  
Machined Surface ◽  
Convex Surfaces ◽  
Machining Errors ◽  
End Mills ◽  
Tool Deflections ◽  
Cutting Modes

Cutting forces and machining error in contouring of concave and convex surfaces using helical ball end mills are theoretically investigated. The cutting forces are evaluated based on the theory of oblique cutting. The machining errors resulting from the tool deflections due to these forces are evaluated at various points of the machined surface. The influence of various cutting conditions and cutting modes on machining error is investigated and discussed.

Development of the cBN Electroplated End-Mill for High Precision Machining of CFRP

2020 ◽  
Author(s):  
Shinnosuke Yamashita ◽  
Tatsuya Furuki ◽  
Hiroyuki Kousaka ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
...  
Keyword(s):  
Surface Roughness ◽  
End Milling ◽  
Drop Out ◽  
End Mill ◽  
Machined Surface ◽  
Side Milling ◽  
Reinforced Plastics ◽  
Milled Surface ◽  
Grinding Conditions ◽  
Grinding Tool

Abstract Recently, the demand of carbon fiber reinforced plastics (CFRP) has been rapidly increased in various fields. In most cases, CFRP products requires a finish machining like cutting or grinding. In the case of an end-milling, burrs and uncut fibers are easy to occur. On the other hand, a precise machined surface and edge will be able to obtain by using the grinding tool. Therefore, this research has been developed a novel the cBN electroplated end-mill that combined end-mill and grinding tool. In this report, the effectiveness of developed tool was investigated. First, the developed tool cut the CFRP with side milling. As the result, the cBN abrasives that were fixed on the outer surface of developed tool did not drop out. Next, the end-milled surface of CFRP was ground with the developed tool under several grinding conditions based on the Design of Experiment. Consequently, the optimum grinding condition that can obtain the sharp edge which does not have burrs and uncut fibers was found. However, surface roughness was not good enough. Thus, an oscillating grinding was applied. In addition, the theoretical surface roughness formula in case using the developed tool was formularized. As the result, the required surface roughness in the airplane field was obtained.

Surface Integrity Studies in Ball End Milling of Thin Shaped Cantilever Inconel 718

2014 ◽  
Author(s):  
Nandkumar N. Bhopale ◽  
Raju S. Pawade
Keyword(s):  
Surface Integrity ◽  
Inconel 718 ◽  
Tool Path ◽  
Surface Defects ◽  
End Milling ◽  
Surface Region ◽  
Lower Surface ◽  
Machined Surface ◽  
Ball End Milling ◽  
Integrity Analysis

The paper presents the surface integrity analysis in ball end milling of thin shaped cantilever plate of Inconel 718. It is noticed that the workpiece deflection has significantly contributed to machined surface integrity in terms of surface topography and subsurface microhardness. The ball end milling performed with 15° workpiece inclination with horizontal tool path produced higher surface integrity which varies with the location of machined surface region. In general, the mid portion of the machined plate shows lower surface roughness and microhardness with less surface defects.

scholarly journals Experimental and Numerical Analysis of High-Speed Internally Cooled Milling

CONVERTER ◽  
2021 ◽  
pp. 748-756
Author(s):  
Ningxia Yin Et al.
Keyword(s):  
High Speed ◽  
End Milling ◽  
Double Helix ◽  
Channel Structure ◽  
Dynamics Simulation ◽  
Thermal Dissipation ◽  
Machined Surface ◽  
Milling Tool ◽  
Internally Cooled ◽  
Cooling Technology

Advanced cooling technology is a crucial measure of thermal dissipation for high-speed end-milling. In order to get an appropriate cooling technology and decrease the negative effects of traditional wet cutting, internally cooled cutting has been paid more and more attention. Because of interrupted cutting and uneven force, there was few application and investigation on internally cooled end-milling. In the paper, the effect of the end-milling tool with different internally cooled channel structure has been researched by experiment and theoretical analysis. The experimental results indicate that the end-milling tool with double helix channels carried out best machined surface quality. And the experiment result was also been analyzed and explained by computational fluid dynamics simulation, which provides a basis for the applying of the high-speed internally cooled end-milling tool.

scholarly journals Influence of Chatter of VMC Arising During End Milling Operation and Cutting Conditions on Quality of Machined Surface

1970 ◽  
Vol 2 (1) ◽  
Author(s):  
A.K.M.N. Amin, M.A. Rizal, and M. Razman
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Metal Removal ◽  
End Milling ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
End Mill ◽  
Machined Surface ◽  
Operating Cycle ◽  
Wide Range

Machine tool chatter is a dynamic instability of the cutting process. Chatter results in poor part surface finish, damaged cutting tool, and an irritating and unacceptable noise. Exten¬sive research has been undertaken to study the mechanisms of chatter formation. Efforts have been also made to prevent the occurrence of chatter vibration. Even though some progress have been made, fundamental studies on the mechanics of metal cutting are necessary to achieve chatter free operation of CNC machine tools to maintain their smooth operating cycle. The same is also true for Vertical Machining Centres (VMC), which operate at high cutting speeds and are capable of offering high metal removal rates. The present work deals with the effect of work materials, cutting conditions and diameter of end mill cutters on the frequency-amplitude characteristics of chatter and on machined surface roughness. Vibration data were recorded using an experimental rig consisting of KISTLER 3-component dynamometer model 9257B, amplifier, scope meters and a PC.  Three different types of vibrations were observed. The first type was a low frequency vibration, associated with the interrupted nature of end mill operation. The second type of vibration was associated with the instability of the chip formation process and the third type was due to chatter. The frequency of the last type remained practically unchanged over a wide range of cutting speed.  It was further observed that chip-tool contact processes had considerable effect on the roughness of the machined surface.Key Words: Chatter, Cutting Conditions, Stable Cutting, Surface Roughness.

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