Volumetric Positioning Errors of CNC Machining Tools and Laser Sequential Step Diagonal Measurement

2006 ◽  
Vol 315-316 ◽  
pp. 98-102 ◽  
Author(s):  
J.H. Shen ◽  
H.T. Zhang ◽  
Hong Tao Cao ◽  
Jian Guo Yang ◽  
C. Wang
Keyword(s):  
Machine Tools ◽  
Measurement Method ◽  
Measurement Data ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Transformation Matrices ◽  
Positioning Errors ◽  
Analysis Measurement ◽  
Key Factor

The volumetric positioning precision of CNC machine tools is the key factor to get high machining precision, so the analysis, measurement and compensation of the volumetric error is becoming more and more important. In this paper, the modeling results of 3-axes CNC machine tools with four different configurations are given based on rigid body theory and homogeneous coordination transformation matrices. An improved sequential step diagonal measurement method is proposed and analyzed because the current laser measurement methods are complex and time cost. At the final section of the paper, the measurement data was applied into the error compensation and the sequential step diagonal measurement method was validated efficient and convenient.

CNC Machine Tools

2009 ◽  
pp. 165-187 ◽  
Author(s):  
Xun Xu
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Manufacturing Industry ◽  
Human Action ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Cnc Machines ◽  
Time Required

The introduction of CNC machines has radically changed the manufacturing industry. Curves are as easy to cut as straight lines, complex 3-D structures are relatively easy to produce, and the number of machining steps that required human action has dramatically reduced. With the increased automation of manufacturing processes with CNC machining, considerable improvements in consistency and quality can be achieved. CNC automation reduced the frequency of errors and provided CNC operators with time to perform additional tasks. CNC automation also allows for more flexibility in the way parts are held in the manufacturing process and the time required to change the machine to produce different components. In a production environment, a series of CNC machines may be combined into one station, commonly called a “cell”, to progressively machine a part requiring several operations. CNC controller is the “brain” of a CNC machine, whereas the physical configuration of the machine tool is the “skeleton”. A thorough understanding of the physical configuration of a machine tool is always a priority for a CNC programmer as well as the CNC machine tool manufacturers. This chapter starts with a historical perspective of CNC machine tools. Two typical types of CNC machine tools (i.e. vertical and horizontal machining centres) are first discussed. Tooling systems for a CNC machine tool are integral part of a CNC system and are therefore elaborated. Also discussed are the four principal elements of a CNC machine tool. They are machine base, machine spindle, spindle drive, and slide drive. What letter should be assigned to a linear or rotary axis and what if a machine tool has two sets of linear axes? These questions are answered later in the chapter. In order for readers to better comprehend the axis and motion designations, a number of machine tool schematics are given.

A unified manufacturing resource model for representation of computerized numerically controlled machine tools

2009 ◽  
Vol 223 (5) ◽  
pp. 463-483 ◽  
Author(s):  
P Vichare ◽  
A Nassehi ◽  
S Newman
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Manufacturing System ◽  
Cutting Tools ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Resource Model ◽  
Machining System ◽  
Manufacturing Resource

The capability of any manufacturing system primarily depends on its available machine tools. Thus machine tool representation is a vital part of modelling any manufacturing system. With the rapid advances in computerized numerically controlled (CNC) machines, machine tool representation has become a more challenging task than ever before. Today's CNC machine tools are more than just automated manufacturing machines, as they can be considered multi-purpose, multi-tasking, and hybrid machining centres. This paper presents a versatile methodology for representing such state-of-the-art CNC machining system resources. A machine tool model is a conceptual representation of the real machine tool and provides a logical framework for representing its functionality in the manufacturing system. There are several commercial modelling tools available in the market for modelling machine tools. However, there is no common methodology among them to represent the wide diversity of machine tool configurations. These modelling tools are either machine vendor specific or limited in their scope to represent machine tool capability. In addition, the current information models of STEP-NC, namely ISO 14649, can only describe machining operations, technologies, cutting tools, and product geometries. However, they do not support the representation of machine tools. The proposed unified manufacturing resource model (UMRM) has a data model which can fill this gap by providing machine specific data in the form of an EXPRESS schema and act as a complementary part to the STEP-NC standard to represent various machine tools in a standardized form. UMRM is flexible enough to represent any type of CNC machining centre. This machine tool representation can be utilized to represent machine tool functionality and consequential process capabilities for allocating resources for process planning and machining.

scholarly journals Positioning Errors Measurement of CNC Machine Tools Based on J-DBB Method

2021 ◽  
Vol 11 (24) ◽  
pp. 11770
Author(s):  
Tao Sun ◽  
Wen Wang ◽  
Zhanfeng Chen ◽  
Yewen Zhu ◽  
Kaifei Xu ◽  
...  
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Degree Of Freedom ◽  
Ball Screw ◽  
Cnc Machine Tools ◽  
Positioning Error ◽  
Cnc Machine Tool ◽  
Spherical Joint ◽  
Cnc Machine ◽  
Positioning Errors

Due to the errors of the servo system and the errors of the ball screw drive system, the positioning errors inevitably occur in the process of CNC machine tools. The measurement of traditional equipment is limited by a fixed measurement radius and a single degree of freedom, which can only be measured within a fixed plane. In this paper, four different positioning errors of CNC machine tools are first measured at full scale by using J-DBB (a modified double ball bar with one spherical joint connecting two bars) method. The J-DBB device uses a three-degree-of-freedom spherical joint as a connecting part, which realizes that the measurement radius can be continuously changed, and the measurement space is a spatial sphere. First, the principle of the J-DBB method is briefly introduced. Next, four typical positioning errors of CNC machine tools are analyzed and examined, which contain the uniform contraction error of ball screw and linear grating, periodic error of the ball screw and linear grating, interference of measurement devices error, and opposite clearance error. In the end, the trajectories of the CNC machine tool spindle with a single positioning error are simulated by using the J-DBB method. The results reveal that this method can be used for the positioning error of machine tools, which helps to better understand the spatial distribution of CNC machine tool errors and provides guidance for the reasonable selection of working areas to improve the machining accuracy of parts.

Research on Machining Method of Complex Surface Face Gears

2012 ◽  
Vol 163 ◽  
pp. 233-237
Author(s):  
Yan Zhong Wang ◽  
Liang Wei Hou ◽  
Yan Qiang Liu ◽  
Rong Shen ◽  
Can Hui Wu ◽  
...  
Keyword(s):  
Machine Tools ◽  
Surface Characteristics ◽  
Complex Surface ◽  
Transformation Process ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Face Gear ◽  
Five Axes ◽  
Complex Parts

This paper describes the machining method of complex surface face gear used CNC machine tools and hob cutter, Based on surface characteristics and gear hob principle. A coordinate transformation process is explained in detail in the five axes CNC machining of complex parts. A CNC hob method is proposed about surface orthogonal gear. An experiment is done for validating the method.

Reliability Study of CNC Machining Centers

2011 ◽  
Vol 418-420 ◽  
pp. 581-584
Author(s):  
Yan Ma ◽  
Wei Li ◽  
Dan Ping Li
Keyword(s):  
Machine Tools ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Feed Speed ◽  
The Finite Element Method ◽  
Cnc Machine ◽  
Spindle System ◽  
Machining Center ◽  
Criticality Analysis ◽  
Cnc Machining Center

CNC machining centers were analyzed by the failure mode, effect and criticality analysis (FMECA) method for identifying the weakest links of a CNC machining center and obtaining that the spindle system is the primary factor that affects the reliability of CNC machining centers. The spindle system was analyzed at different feed speed by the finite element method. The results have important guiding significance for the reliability research of CNC machine tools.

Reform of CNC Machine Tool and Programming Based on CDIO Model

2012 ◽  
Vol 214 ◽  
pp. 939-943
Author(s):  
Jing Ping Liu ◽  
Yu Zhong Li
Keyword(s):  
Machine Tools ◽  
Core Curriculum ◽  
Active Role ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Practical Capacity ◽  
Machinery Manufacturing ◽  
Teaching Ideas

CNC machine tools and programming is a professional core curriculum of the vocational colleges in machinery manufacturing and automation, and CNC machining technology. This course involves teaching and professional practice, which requires us to improve teaching methods, improve the quality of teaching to promote students 'understanding of CNC machine tools and programming course and mastery, in order to develop students' practical capacity. In this paper, we use the conception, design, implementation, and operation of the CDIO model implementation of teaching reform, providing engineering teaching model with a new teaching ideas, and this also plays an active role in the training to cultivate innovative talents.

scholarly journals Deflection Error Prediction and Minimization in 5-Axis Milling Operations of Thin-Walled Impeller Blades

2020 ◽  
Author(s):  
Mohsen Soori ◽  
Mohammed Asmael
Keyword(s):  
Machine Tools ◽  
Turbine Blades ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Machining Parameters ◽  
Cnc Machine ◽  
Virtual Machining ◽  
Machining System ◽  
Thin Walled ◽  
Machining Operations

Abstract To enhance accuracy as well as efficiency in process of machining operations, the virtual machining systems are developed. Free from surfaces of sophisticated parts such as turbine blades, airfoils, impellers, and aircraft components are produced by using the 5-axis CNC machine tools which can be analyzed and developed by using virtual machining systems. The machining operations of thin walled structures such as impeller blades are with deflection errors due to cutting forces and cutting temperatures. The flexibility of thin walled impeller blades can cause machining defects such as overcut or undercut. So, the desired accuracy in the machined impeller blades can be achieved by decreasing the deflection error in the machining operations. To minimize the deflection of machined impeller blades, optimized machining parameters can be obtained. An application of virtual machining system in predicting and minimizing the deflection errors of 5-Axis CNC machining operations of impeller blades is presented in the study to increase accuracy and efficiency in process of part production. The finite element analysis is applied to obtain the deflection error in machined impeller blades. In order to minimize the deflection error of impeller blades in the machining operations, the optimization methodology based on the Genetic algorithm is applied. The impeller is machined by using the 5-axis CNC machine tool in order to validate the developed virtual machining system in the study. Then, the machined impeller is measured by using the CMM machines to obtain the deflection error. As a result, the deflection error of in machining operations of impeller by using 5-Axis CNC machine tools can be decreased in order to enhance accuracy and efficiency of part manufacturing.

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