The Effect of Tool Flexibility on Back-Cutting in End Milled Surfaces

1999 ◽  
Vol 121 (3) ◽  
pp. 532-537 ◽  
Author(s):  
S. N. Melkote ◽  
J. W. Sutherland ◽  
C. King
Keyword(s):  
Cutting Force ◽  
Surface Texture ◽  
Surface Characteristics ◽  
End Mill ◽  
Force System ◽  
Feed Force ◽  
Milled Surface ◽  
Cutting Effect ◽  
Surface Profiles ◽  
Good Agreement

End milled surface texture is inhomogeneous and often exhibits complex lay patterns. An important contributing factor to these surface characteristics is the back-cutting effect. This effect causes cutter tooth mark patterns on the surface in the forward and reverse tool feed directions. In this paper, the dependence of back-cutting on end mill flexibility and its influence on the slot floor surface texture are modeled and experimentally verified. It is shown that the extent to which tool flexibility affects back-cutting is determined by the resultant cutting force system and not the feed force alone. The variation in the amount of back-cutting typically observed across the width of a milled slot is also explained by this model. The model, although simple in form, yields reasonably good agreement with the measured surface profiles.

Identification of Spindle Integrated Force Sensor’s Transfer Function for Modular End Mills

Manufacturing ◽  
2003 ◽  
Author(s):  
Simon S. Park ◽  
Yusuf Altintas
Keyword(s):  
Transfer Function ◽  
Cutting Force ◽  
Force Sensor ◽  
Force Sensors ◽  
End Mill ◽  
Force System ◽  
Automated Calibration ◽  
End Mills ◽  
Proven Method

A spindle integrated cutting force system is studied in the paper. Piezoelectric force sensors are embedded to the spindle housing. The transfer function between the force experienced at the end mill and measured at the spindle integrated force sensor varies depending on the stick out length of the end mill. The paper proposes a method which predicts the transfer function of the overall system by coupling the receptances of the analytically modeled end mill and experimentally measured spindle structures. The experimentally proven method allows automated calibration of the spindle integrated force system whenever a tool change occurs.

Identification of Spindle Integrated Force Sensor’s Transfer Function for Modular End Mills

2005 ◽  
Vol 128 (1) ◽  
pp. 146-153 ◽  
Author(s):  
Simon S. Park
Keyword(s):  
Transfer Function ◽  
Cutting Force ◽  
Cutting Forces ◽  
High Frequency ◽  
Force Sensor ◽  
Frequency Bandwidth ◽  
End Mill ◽  
Force System ◽  
End Mills ◽  
Proven Method

A spindle integrated cutting force system where piezoelectric force sensors are embedded in the spindle housing is studied. The transfer function between the force experienced at the end mill and measured at the spindle integrated force sensor varies depending on the tool length sticking out. In the paper, a method is proposed to predict the transfer function of the overall system by coupling the receptances of the analytically modeled end mill and experimentally measured spindle structures. The experimentally proven method allows for the automated calibration of the spindle integrated force system whenever a tool change occurs to accurately measure high-frequency bandwidth cutting forces.

scholarly journals Surface Texture after Turning for Various Workpiece Rigidities

Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Michal Dobrzynski ◽  
Karolina Mietka
Keyword(s):  
Surface Texture ◽  
Surface Characteristics ◽  
304 Stainless Steel ◽  
Aisi 304 ◽  
Aisi 304 Steel ◽  
Surface Irregularities ◽  
Surface Microgeometry ◽  
Surface Profiles ◽  
Turned Parts ◽  
Positive Effect

In the paper, we present an analysis of the surface texture of turned parts with L/D (length/diameter) ratios of 6 and 12 and various rigidity values. The studies were carried out on samples made of S355JR steel and AISI 304 stainless steel. A detailed analysis of 2D surface profiles was carried out by using a large number of parameters that allowed us to distinguish significant differences in the surface microgeometry, which confirmed that determining surface characteristics from one height parameter (Ra—arithmetical mean height) is far from sufficient. The obtained results indicate significantly better roughness and waviness values of the AISI 304 steel surfaces in terms of its size, periodicity, and regularity. Therefore, the turning process of AISI 304 shafts with low rigidity allows one to be able to achieve better quality texture and have a positive effect on the general properties of a workpiece. In all tested samples, surface irregularities decreased along with the distance from the tailstock. The shafts with an L/D ratio of 12 had worse surfaces in the first two sections due to lower rigidity. The results received close to the three-jaw chuck, regardless of the L/D ratio and material type, demonstrated similar waviness and roughness parameters and profiles.

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.

FRACTAL-BASED ANALYSIS OF THE VARIATIONS OF CUTTING FORCES ALONG DIFFERENT AXES IN END MILLING OPERATION

Fractals ◽  
2018 ◽  
Vol 26 (06) ◽  
pp. 1850089 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI AKHAVAN FARID ◽  
TECK SENG CHANG
Keyword(s):  
Fractal Dimension ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Fractal Theory ◽  
Radial Force ◽  
Machining Conditions ◽  
Feed Force ◽  
Milling Operation ◽  
Force Signal

Analysis of cutting forces in machining operation is an important issue. The cutting force changes randomly in milling operation where it makes a signal by plotting over time span. An important type of analysis belongs to the study of how cutting forces change along different axes. Since cutting force has fractal characteristics, in this paper for the first time we analyze the variations of complexity of cutting force signal along different axes using fractal theory. For this purpose, we consider two cutting depths and do milling operation in dry and wet machining conditions. The obtained cutting force time series was analyzed by computing the fractal dimension. The result showed that in both wet and dry machining conditions, the feed force (along [Formula: see text]-axis) has greater fractal dimension than radial force (along [Formula: see text]-axis). In addition, the radial force (along [Formula: see text]-axis) has greater fractal dimension than thrust force (along [Formula: see text]-axis). The method of analysis that was used in this research can be applied to other machining operations to study the variations of fractal structure of cutting force signal along different axes.

A Role of the Resultant Cutting Force in Deep-Hole Drilling

1999 ◽  
Author(s):  
V. N. Latinovic ◽  
V. P. Astakhov ◽  
M. O. M. Osman
Keyword(s):  
Cutting Force ◽  
Static Stability ◽  
Optimal Location ◽  
Design Criterion ◽  
Hole Drilling ◽  
Deep Hole ◽  
Force Vector ◽  
Force System ◽  
Deep Hole Drilling

Abstract This paper present results of the analysis of a tool static stability in deep-hole drilling. The analysis has been carried out to determine the optimal location of the drill guide pads relative to the drill’s cutters (based upon criteria of equal total pad reactions and equal stability indicators). It is demonstrated that the optimal location can be achieved under asymmetrical location of the supporting pads relative to the direction of the resultant cutting force in a plane perpendicular to the drill axis. By consideration of the drill static force system in the plane which contains the drill axis and the resultant cutting force vector, a new design criterion is proposed. The essence of this concept is to design the deep-hole drills with minimum rubbing and wear of the guide pads and provide for the tool self-piloting.

Milling Force Prediction Model for Five-Axis Machining of Freeform Surface Considering Mesoscopic Size Effect

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
Minglong Guo ◽  
Zhaocheng Wei ◽  
Minjie Wang ◽  
Jia Wang ◽  
Shengxian Liu
Keyword(s):  
Dislocation Density ◽  
Size Effect ◽  
Prediction Model ◽  
Cutting Force ◽  
Freeform Surface ◽  
End Mill ◽  
Ball End Mill ◽  
Milling Force ◽  
Force Prediction ◽  
Five Axis

Abstract The core parts with the characteristic of freeform surface are widely used in the major equipment of various fields. Cutting force is the most important physical quantity in the five-axis CNC machining process of core parts. Not only in micro-milling, but also in macro-milling, there is also an obvious size effect, especially in medium- and high-speed milling, which is frequently ignored. In this paper, the milling force prediction model for five-axis machining of a freeform surface with a ball-end mill considering the mesoscopic size effect is established. Based on the characteristics of cutting thickness in macro-milling, a new dislocation density correction form is proposed, and a new experiment is designed to identify the dislocation density correction coefficient. Therefore, the shear stress calculated in this paper not only reflects the cutting dynamic mechanical characteristics but also considers the mesoscopic size effect. A linear function is proposed to describe the relationship between friction coefficient and cutting speed, cutter rake angle, and cutting thickness. Considering cutter run-out, the micro-element cutting force in the shear zone and plough zone are analyzed. The cutting geometry contact between the freeform surface and the ball-end mill is analyzed analytically by the space limitation method. Finally, the total milling force is obtained by summing all the force vectors of cutting edge micro-elements within the in-cut cutting edge. In the five-axis machining experiment of freeform surface, the theoretically predicted results of milling forces are in good agreement with the measured results in trend and amplitude.

Experimental Study on the Effect of Surface Integrity on Fatigue Performance of Aero-Engine Blades

2021 ◽  
Author(s):  
Yun Huang ◽  
Shaochuan Li ◽  
Guijian Xiao ◽  
Benqiang Chen ◽  
Yi He ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Test ◽  
Surface Texture ◽  
Surface Characteristics ◽  
Service Performance ◽  
Aero Engine ◽  
Vibration Fatigue

Abstract As the core component of aero-engine, the service performance of aero-engine blade has an important influence on the engine’s reliability and safety performance. Existing studies have shown that machined surface characteristics affect the fatigue strength of components. However, current studies are all based on regular fatigue samples. The structure of blades different from fatigue samples, and the influence mechanism of structural differences on the service performance of blades is still unclear. In addition, the conventional fatigue test conditions are not representative for the blades’ actual service conditions, so it is difficult to realize the processing process for the service performance optimization. In this study, the aero-engine blades processed by abrasive belt grinding and the vibration fatigue test bench were used to explore the influence of surface roughness, surface texture, and surface residual stress on the fatigue performance of aero-engine blades under actual working conditions. The aero-engine blades were ground with different process parameters to obtain different single-factor surface characteristics. By comparing the vibration fatigue life of blades with different surface features, the influence degree of each surface feature on the fatigue life was explored. Results showed that surface roughness has the greatest influence on fatigue strength, followed by residual stress, and surface texture has the least influence on fatigue strength.

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