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

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.

Manufacturing ◽  
2003 ◽  
Author(s):  
Simon S. Park ◽  
Yusuf Altintas

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.


2011 ◽  
Vol 675-677 ◽  
pp. 681-684
Author(s):  
Nobu Gomi ◽  
N. Ishii ◽  
R. Hozumi ◽  
H. Kumehara

Evaluation of manufacturing process in milling by direct measurement of cutting force is considered to be effective comparing to indirect measurement of electricity. This paper proposed a new evaluation method of end-mills by the direct measurement of cutting force. Cutting forces were precisely obtained by a 3-component dynamometer during end milling. Each flute cutting forces was evaluated for two types of end-mills (non wear-out, wear-out) by wave patterns of cutting force. A distinctive difference in the two types of end-mills has been clearly seen. The effectiveness of the proposed evaluation method has been clarified.


2018 ◽  
Vol 34 (2) ◽  
pp. 343-353
Author(s):  
A. Bulent Koc Koc ◽  
Bo Liu

Abstract. Ultrasound-assisted cutting has been used to cut materials with high precision, improved quality and reduced cutting forces. The research objective was to investigate the effects of high-frequency vibrations on the cutting force and cutting energy of switchgrass and miscanthus stems. Laboratory experiments were conducted on individual biomass stems at cutting speeds between 3 and 400 mm/s. An experimental cutting system with an ultrasound generator, an ultrasonic blade, a load cell, and a data acquisition system was developed. The custom designed blade was 5-cm wide and vibrated at 19.551 kHz with 2.8 µm tip vibration amplitude. There were significant measured differences in the cutting forces and cutting energies between conventional cutting and ultrasonic cutting of switchgrass and miscanthus stems (p < 0.05). These results suggest that the use of high-frequency vibrations reduce cutting force and cutting energy of both switchgrass and miscanthus stems. Ultrasound-assisted cutting reduced the cutting energy of switchgrass by 66.85% at 100 mm/s and miscanthus by 80.58% at 30 mm/s. However, ultrasonic cutting did not have a significant effect on the cutting force and cutting energy when the cutting speed was equal to or greater than the blade tip vibration speed. The results of this research should be useful for adapting the ultrasonic technology in biomass harvesting, particle size reduction, and processing equipment. Keywords: Biomass, Blades, Energy, Finite element analysis, Miscanthus, Switchgrass, Ultrasonics.


Author(s):  
W. Ferry ◽  
Y. Altintas

Jet engine impeller blades are flank-milled with tapered, helical, ball-end mills on five-axis machining centers. The impellers are made from difficult-to-cut titanium or nickel alloys, and the blades must be machined within tight tolerances. As a consequence, deflections of the tool and flexible workpiece can jeopardize the precision of the impellers during milling. This work is the first of a two part paper on cutting force prediction and feed optimization for the five-axis flank milling of an impeller. In Part I, a mathematical model for predicting cutting forces is presented for five-axis machining with tapered, helical, ball-end mills with variable pitch and serrated flutes. The cutter is divided axially into a number of differential elements, each with its own feed coordinate system due to five-axis motion. At each element, the total velocity due to translation and rotation is split into horizontal and vertical feed components, which are used to calculate total chip thickness along the cutting edge. The cutting forces for each element are calculated by transforming friction angle, shear stress and shear angle from an orthogonal cutting database to the oblique cutting plane. The distributed cutting load is digitally summed to obtain the total forces acting on the cutter and blade. The model can be used for general five-axis flank milling processes, and supports a variety of cutting tools. Predicted cutting force measurements are shown to be in reasonable agreement with those collected during a roughing operation on a prototype integrally bladed rotor (IBR).


Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950013 ◽  
Author(s):  
AHMAD THUFFAIL THASTHAKEER ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG ◽  
HAMIDREZA NAMAZI

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.


Author(s):  
Simon S. Park ◽  
Y. Altintas

This paper presents a dynamically compensated Spindle Integrated Force Sensor (SIFS) system to measure cutting forces. Piezo-electric force sensors are integrated to the stationary spindle housing. The structural dynamic model between the cutting forces acting on the tool tip and the measured forces at the spindle housing is identified. The system is first calibrated to compensate the influence of spindle run-out and unbalance at different speeds. Using both the cutting force and acceleration sensor signals measured at the spindle housing, a Kalman Filter is designed to filter the influence of structural modes on the force measurements. The frequency bandwidth of the proposed sensor system is expanded from 300 Hz to about 800 Hz with the proposed sensing and the signal processing method.


2015 ◽  
Vol 2 (4) ◽  
pp. 233-247 ◽  
Author(s):  
Yung-Chou Kao ◽  
Nhu-Tung Nguyen ◽  
Mau-Sheng Chen ◽  
Shyh-Chour Huang

Abstract In this paper, the cutting force calculation of ball-end mill processing was modeled mathematically. All derivations of cutting forces were directly based on the tangential, radial, and axial cutting force components. In the developed mathematical model of cutting forces, the relationship of average cutting force and the feed per flute was characterized as a linear function. The cutting force coefficient model was formulated by a function of average cutting force and other parameters such as cutter geometry, cutting conditions, and so on. An experimental method was proposed based on the stable milling condition to estimate the cutting force coefficients for ball-end mill. This method could be applied for each pair of tool and workpiece. The developed cutting force model has been successfully verified experimentally with very promising results. Highlights By investigation of the stable cutting conditions in milling process, the linear function of average cutting force and feed per flute was successfully verified. A combined theoretical-experimental method was proposed with an effective model for the determination of cutting force coefficients in ball-end mill process.


2016 ◽  
Vol 10 (3) ◽  
pp. 372-380 ◽  
Author(s):  
Akira Hosokawa ◽  
◽  
Naoya Hirose ◽  
Takashi Ueda ◽  
Tomohiro Koyano ◽  
...  

Side milling tests of CFRP (carbon fiber reinforced plastics) containing thermosetting resin are carried out by TiAlN/AlCrN-coated, H2-free DLC (diamond-like carbon)-coated, and CVD diamond-coated carbide end mills without coolant. Two types of end mills having different helix angles of 30° and 60° are used. The film thickness and surface smoothness are varied for the DLC-coated end mills. The cutting characteristics are evaluated by tool wear and surface integrity (i.e., 3D profiles of the machined surface, generation of fluffing, delamination, and pull-out of the carbon fibers). The cutting force and tool flank temperature are also examined for the two types of CFRP composites and the helix angle of the end mill. “Inclination milling,”in which the end mill is tilted so that the resultant cutting force acts parallel to the work surface, is proposed as a novel technique to be used with a high-helix angle end mill. This unique approach enables the reduction of tool wear and improves the surface integrity of machined CFRP surfaces.


Fractals ◽  
2018 ◽  
Vol 26 (05) ◽  
pp. 1850078 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG

It is known that geometry of cutting tool affects the cutting forces in machining operations. In addition, the value of cutting forces changes during machining operations and creates a chaotic time series (signal). In this paper, we analyze the variations of the complex structure of cutting force signal in rough end milling operation using fractal theory. In fact, we analyze the variations of cutting force signal due to variations of tool geometry (square end mill versus serrated end mill). In case of each type of end mill, we did the machining operation in wet and dry conditions. Based on the results, the fractal structure of cutting force signal changes based on the type of milling tool. We also did the complexity analysis using approximate entropy to check the variations of the complexity of cutting force signal, where the similar behavior of variations between different conditions was obtained. The method of analysis that was used in this research can be applied to other machining operations to study the influence of different machining parameters on variations of fractal structure of cutting force.


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