Feed Rate Influence on Motion Error Characteristics of CNC Vertical Milling Machine

2013 ◽  
Vol 393 ◽  
pp. 36-41
Author(s):  
Azman Ahmad Bakir ◽  
Zainal Abidin Ahmad ◽  
Mazlan Mohamed ◽  
Mohd Nor Hakim Hassan ◽  
Muhamad Iqbal bin Ahmad

The increasing number of the Computer Numerical Control (CNC) machines usage in the manufacturing field appears to suggest that they are expected to be in good running condition. Machine tools such as CNC vertical milling machines are meant to produce precise work parts. Motion errors are factors which can directly affect the accuracy of the machine. This study presents an opportunity for interested parties to understand the characteristics of motion errors that exist in the CNC vertical milling machines with different feed rate settings. The purpose of this project is to find out any abnormalities apparent to the machine performance as the feed rate setting is increased. The motion errors of the CNC machines were examined by using a measuring device, namely Double Ball Bar (DBB). This equipment is designed to examine machine performance by measuring the accuracy of its movements. This device, which has two balls of identical size at the end of the bar, was mounted on a spindle and onto a special holder which is mounted on the working table. The machine is programmed to move in a circular motion, clockwise and anti-clockwise in three planes, XY, YZ and ZX. Any deviation from the standard data will represent the imperfection of the machines condition, especially mechanical components such as the slide bearing, spindle bearing or servo motor responses. By knowing the most significant error origin, the corrective countermeasures can then be carried out.

Author(s):  
V. A. Bahvalov

The article describes the process of honing the details of command artillery systems, in particular the process of honing planes wedge gate of medium-caliber guns. The article is an analysis of the kinematic scheme of the device and the selected gear ratio device that provides even wear a uniform honing stones and metal removal with a flat machined surface of the work piece due to the commission of the cutting grains honing stones complex movements in the horizontal plane. Next each of the cutting grains will not be repeated for the entire processing cycle. Kinematic diagram of the device with the established and enshrined in the radial grooves of the disc honing stones is implemented in the design and manufacture of devices for honing on vertical milling machines planes wedge gate artillery systems. Investigation of the process of honing the flat specimens made of high-strength gun steels viscous with plan dimensions 130x240 mm possible to determine the rational parameters of flat honing process.Production testing device for honing planes wedge gate of one of the artillery pieces on a vertical milling machine performed at one of the engineering confirmed the efficiency of the device for a flat honing. Honing wedge planes shutter serial products (76 mm caliber gun) on a vertical milling machine using the apparatus discussed in the article improves the processing performance in comparison with conventional processing means 20…35 %. In this case, stability is regulated product design documentation form accuracy and size of the part and the surface roughness of the planes of the wedge gate Ra £ 0,32 microns.


Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8431
Author(s):  
Arturo Yosimar Jaen-Cuellar ◽  
Roque Alfredo Osornio-Ríos ◽  
Miguel Trejo-Hernández ◽  
Israel Zamudio-Ramírez ◽  
Geovanni Díaz-Saldaña ◽  
...  

The computer numerical control (CNC) machine has recently taken a fundamental role in the manufacturing industry, which is essential for the economic development of many countries. Current high quality production standards, along with the requirement for maximum economic benefits, demand the use of tool condition monitoring (TCM) systems able to monitor and diagnose cutting tool wear. Current TCM methodologies mainly rely on vibration signals, cutting force signals, and acoustic emission (AE) signals, which have the common drawback of requiring the installation of sensors near the working area, a factor that limits their application in practical terms. Moreover, as machining processes require the optimal tuning of cutting parameters, novel methodologies must be able to perform the diagnosis under a variety of cutting parameters. This paper proposes a novel non-invasive method capable of automatically diagnosing cutting tool wear in CNC machines under the variation of cutting speed and feed rate cutting parameters. The proposal relies on the sensor information fusion of spindle-motor stray flux and current signals by means of statistical and non-statistical time-domain parameters, which are then reduced by means of a linear discriminant analysis (LDA); a feed-forward neural network is then used to automatically classify the level of wear on the cutting tool. The proposal is validated with a Fanuc Oi mate Computer Numeric Control (CNC) turning machine for three different cutting tool wear levels and different cutting speed and feed rate values.


2009 ◽  
Vol 407-408 ◽  
pp. 155-158
Author(s):  
Takekazu Sawa ◽  
Masayuki Okabe ◽  
Akio Siga ◽  
Masami Mutoh ◽  
Takayuki Kurihara ◽  
...  

In this study, covering for the skill training centers in Japan, we performed surveillance study about the functions required for the general purpose milling machines for educational skill training. As a result, it was found that the function of recognizing machining state is desired for milling machines besides higher stiffness, higher accuracy, and the ease of chip treatment. Based on this fact, the general purpose vertical milling machine was developed for educational skill training. First, a beginner's work analysis was conducted and the functions which control the mishandling were developed. The operation mistake has decreased by this function. In addition, the cutting power inspection system was built by using high sensitive micro-wattmeter. And, the possibility of judgment of tool wear was found by inspecting the change of the wave profile in the wattmeter.


2021 ◽  
Vol 5 (4) ◽  
pp. 129
Author(s):  
Matthew J. Triebe ◽  
Fu Zhao ◽  
John W. Sutherland

Lightweighting is a design strategy to reduce energy consumption through the reduction of mass of a product. Lightweighting can be applied to machine tools to reduce the amount of energy consumed during the use phase. Thus, the energy cost of machine operation will be reduced. One might also hypothesize that since a lighter-weight machine tool requires less material to build, the cost to produce such a machine will be less. However, it may also be the case that lightweighting a machine tool increases its complexity, which will likely drive up the cost to manufacture the machine. To explore the cost drivers associated with building a machine tool, data on the features associated with a wide variety of vertical milling machine tools are collected. Then, empirical cost models are fit to this data. The results from the cost models show that the machine tool mass is a significant cost driver; other key drivers are the number of axes and spindle power. The models are used to predict the cost benefits of lightweighting in terms of mass, which are compared to potential increased manufacturing costs associated with complexities introduced due to lightweighting.


Author(s):  
J R Rivera-Guillen ◽  
R J Romero-Troncoso ◽  
R A Osornio-Rios ◽  
A Domínguez-González

High-quality material manufacture requires the improvement of the computer numerical control (CNC) machine performance. Such task can be achieved by considering the tool trajectory, in which it is important to minimize the acceleration and jerk levels. Previous research works are focused on providing smooth movements at most with C2 continuous trajectories, and the results of using C3 continuity in the trajectory are not evaluated. The contribution of this study is the design of a methodology for obtaining C3 tool trajectories while acceleration and jerk levels are constrained through adaptive feed-rate. C3 and C2 trajectories are executed in a CNC machine. Speed, acceleration, and jerk are monitored in order to validate the proposed methodology and to analyse and quantify the differences between using C2 and using C3 trajectories.


1976 ◽  
Vol 98 (2) ◽  
pp. 614-619 ◽  
Author(s):  
F. A. Burney ◽  
S. M. Pandit ◽  
S. M. Wu

The machine tool dynamics is evaluated under actual working conditions by using a time series technique. This technique develops mathematical models from only one signal, viz., the relative displacement between the cutter and the workpiece. Analysis of the experimental data collected on a vertical milling machine indicates that the new methodology is capable of characterizing the machine tool structure and the cutting process dynamics separately. Furthermore, it can also detect and quantify the interaction between these two subsystems.


2018 ◽  
Vol 8 (11) ◽  
pp. 2232 ◽  
Author(s):  
Chuanchen Bao ◽  
Qibo Feng ◽  
Jiakun Li

Error measurement of a rotary axis is the key to error compensation and to improving motion accuracy. However, only a few instruments can measure all the motion errors of a rotary axis. In this paper, a device based on laser collimation and laser interferometry was introduced for simultaneous measurement of all six degrees-of-freedom motion errors of a rotary axis. Synchronous rotation of the target and reference rotary axes was achieved by developing a proportional–integral–derivative algorithm. An error model for the measuring device was established using a homogeneous transformation matrix. The influences of installation errors, manufacturing errors, and error crosstalk were studied in detail, and compensation methods for them were proposed. After compensation, the repeatability of axial and radial motion errors was significantly improved. The repeatability values of angular positioning error and of tilt motion error around the y axis and x axis were 28.0″, 2.8″, and 3.9″. The repeatability values of translational motion errors were less than 2.8 μm. The comparison experiments show that the comparison errors of angular positioning error and tilt motion error around the y axis were 2.3″ and 2.9″, respectively. These results demonstrate the effectiveness of our method and the error compensation model.


2016 ◽  
Vol 1136 ◽  
pp. 651-654
Author(s):  
Hideki Aoyama ◽  
Duo Zhang

It is frequently the case that the feed rate indicated in a numerical control (NC) program does not obtain in actual machining processes and the cutting tool does not path the points indicated in the NC. A reason underlying such problems is that control gains are not optimized, which causes issues with acceleration and deceleration in the control of machine tools. To address these problems, in this paper, we propose a method for the optimization of control gains using the MATLAB and Simulink software by considering the weight of the workpiece, the controlling distance, and the controlling speed. Simulations confirmed the effectiveness of our proposed optimization.


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