Accuracy Analysis of Machining Process Using a Spindle Probe and a CMM to Reduce the Scrap

2005 ◽  
Author(s):  
Yongjin Kwon
Keyword(s):  
Machine Tool ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Machining Process ◽  
Inspection Time ◽  
Cnc Machine ◽  
Part Quality ◽  
Post Process ◽  
Measuring Machine ◽  
Touch Probe

In-process part inspection using a spindle touch probe has gained a significant importance, mainly because parts can remain on the machine without disrupting the machine setup while inspection is being conducted. This practice leads to a shorter inspection time, improved part accuracies, and reduction of scraps. Recently, intense domestic and international competition has put more importance on part quality in terms of producing parts right the first time and maintaining the consistent quality standards. A literature review revealed that a comparative analysis between in-process gauging using a touch probe and post-process inspection using a coordinate measuring machine (CMM) to ascertain part quality has not been adequately studied. Therefore, there is a need for a study to measure the characteristics of the two inspection techniques. To address the problem, cutting experiments were conducted and measurement data were analyzed using a state-of-the-art CNC machine, a CMM, a touch probe, and a high-precision ballbar system. The experimental data show that machined features and touch probe measurements are affected by the inherent shortcomings in machine tool structure, suggesting a machine tool capability analysis be undertaken in tune with the required tolerance specifications prior to machining operations, rather than solely relying on the touch probe inspection for part quality assessment.

The Research of Five-Axis NC High Efficient Machining Technology for UAV Integral Impeller

2014 ◽  
Vol 598 ◽  
pp. 189-193
Author(s):  
Hui Zhao ◽  
Yu Jun Cai ◽  
Guo He Li
Keyword(s):  
Process Analysis ◽  
Coordinate Measuring Machine ◽  
Machining Process ◽  
Machining Parameters ◽  
Program Optimization ◽  
Cnc Machine ◽  
Rough Machining ◽  
High Efficient ◽  
Measuring Machine ◽  
Five Axis

In this paper, a very detailed process analysis for UAV integral impeller was made. According to the specific processing requirements, the appropriate CNC machine, blank and cutting tools have been choosing. In the rough machining process, various machining strategies have been used for comparing and analyzing, finally a more efficient roughing method with the accurate machining parameters will be obtained. At the same time the machining method have been improved and the processing parameters also have been determined in the semi-finishing process. Through the simulation processing in VERICUT, the possibility of the existence of interference which is usually occurred in the actual processing can be ruled out and the program optimization will be finished in the meantime. Finally, using intelligent three-coordinate measuring machine the consequence will be verified and inspected in the actual machining process.

REAL-TIME MACHINING QUALITY INSPECTION FOR DESIGN FOR MANUFACTURING (DFM)

2005 ◽  
Vol 04 (01) ◽  
pp. 21-36 ◽  
Author(s):  
YONGJIN KWON ◽  
TERESA WU
Keyword(s):  
Real Time ◽  
Measurement Data ◽  
Response Speed ◽  
Design For Manufacturing ◽  
Product Development Process ◽  
Inspection Time ◽  
Quality Inspection ◽  
Positional Accuracy ◽  
Measuring Machine ◽  
Touch Probe

A dynamic, globalized and customer-driven market brings opportunities and threats to companies, depending on the response speed and production strategies. One strategy is Concurrent Engineering (CE) that focuses on improving the product development process, by considering various factors associated with the life cycle of the product from the early stages of the product design. Design for Manufacturing (DFM) has proven to be an effective approach to implement CE concept. Recently, an important DFM concept in machining (i.e. a real-time inspection) has drawn much attention from both academia and industry. This is because intense domestic and international competition has put more emphasis on the part quality to achieve a shorter inspection time, improved part accuracies, and reduced scrap. The current methodology, using a machine mounted touch probe, suffers from the fact that the measurement accuracy is affected by the individual machine tool's positional accuracy and positioning system. To address this concern, the cutting experiments were conducted to collect touch probe measurement data. The data were analyzed to verify whether using a touch probe is suitable for real-time inspection. The analysis results show the touch probe has the higher capability index numbers and consistencies than the coordinate measuring machine (CMM), suggesting that the touch probe can be integrated into DFM as a means of real-time quality inspection.

A Method for Measuring the Systematic Errors of CNC-Machine Tools

2012 ◽  
Vol 271-272 ◽  
pp. 1770-1775
Author(s):  
Qi Gao
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Tool Path ◽  
Laser Interferometer ◽  
Coordinate Measuring Machine ◽  
Calibration Method ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Measuring Machine ◽  
Error Calibration

The method used for measurement and calibration of machine tool errors should be general and efficient. With this method, the machine tool status can be completely identified and its accuracy can be enhanced by software error compensation. The point compensation method can be used as a means for modifying the nominal tool path and on-machine inspection where the machine tool is used as a coordinate measuring machine. The validity of the error calibration method proposed in this' paper was shown using a vertical 3-axis CNC machine with a laser interferometer and a ball bar technique.

scholarly journals Traceability on Machine Tool Metrology: A Review

2017 ◽  
Author(s):  
Unai Mutilba ◽  
Eneko Gomez-Acedo ◽  
Gorka Kortaberria ◽  
Aitor Olarra ◽  
José Antonio Yagüe-Fabra
Keyword(s):  
Machine Tool ◽  
Manufacturing Process ◽  
Machine Tools ◽  
Nuclear Power ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Manufacturing Processes ◽  
Scientific Objective ◽  
Measuring Process ◽  
Measuring Machine

Errors during manufacture of high value components are not acceptable nowadays in driving industries such as energy and transportation. Sectors such as aerospace, automotive, shipbuilding, nuclear power, large science facilities or wind power manufacture complex and accurate components that demand close measurements and fast feedback into manufacturing processes. New measuring technologies are already available in machine tools, including integrated touch probes and fast interface capabilities. They shall provide the possibility to measure the workpiece during or after the manufacturing process, maintaining the original setup of the workpiece and avoiding the manufacturing process from being interrupted to transport the workpiece to a measuring position. However, the traceability of the measurement process on a machine tool is not ensured yet and measurement data is still not fully reliable for process control or product validation. Due to the similarity between a coordinate measuring machine and a machine tool, some of the methods applied for a correct assessment of uncertainty in coordinate measuring machines are adapted to the challenges of a machine tool. The scientific objective is to determine the uncertainty on a machine tool measurement and, in this way, convert it into a machine integrated traceable measuring process. This paper reviews the fundamentals of machine tool metrology.

scholarly journals Measurement Accuracy Assessment for Laser Triangulation 3D Scanning Machine

2020 ◽  
Vol 8 (6) ◽  
pp. 2789-2793
Keyword(s):  
Measurement Accuracy ◽  
Accuracy Assessment ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
3D Scanning ◽  
Laser Triangulation ◽  
Cnc Machine ◽  
3D Scanner ◽  
Calibration Block ◽  
Measuring Machine

Laser triangulation 3D scanning machine is one of many types of 3D scanning technologies that are currently available in the current market. It is mainly use to capture object profiles as well as for measurement. Therefore, the measurement accuracy of laser triangulation 3D scanner was assessed and presented in paper. Three solid aluminum calibration block with known dimensions were fabricated by using CNC machine and these samples were named based on its profiles which are round, square and complex. Besides the laser triangulation 3D scanning machine, two more measuring equipment which are Vernier caliper and coordinate measuring machine were used as benchmarks. Three profiles were chose for each calibration block samples that made up of 9 profiles that have been measured and the deviation between the measuring values were analyzed. The results shown that the lowest deviation values for most of the profiles are from coordinate measuring machine and Vernier caliper measurement data. Nevertheless, the measurement deviation for laser triangulation 3D scanner are found to be comparable with other equipment.

Study on Generation and Optimization Methodology of On-Machine Measurement Schemes for Multi-Axis CNC Machine Tool

2017 ◽  
Author(s):  
Zhao Bohan ◽  
Gao Feng ◽  
Li Yan ◽  
Zhang Dongya ◽  
Zhang Wanli ◽  
...  
Keyword(s):  
Machine Tool ◽  
Large Scale ◽  
Coordinate Measuring Machine ◽  
Measuring Error ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Real Time Control ◽  
Position Detection ◽  
Volumetric Errors ◽  
Measuring Machine

Quality Control (QC) is one of the most important phases in the production process. In tradition, the workpiece must be inspected for dimension and shape errors in the QC lab or Coordinate Measuring Machine (CMM) after being machined, which is time-consuming and labor-intensive, especially for large scale parts. Thus the only practical way to do that is to migrate the critical primary inspection operations upstream from the QC lab or CMM to the production floor, and that’s what On-Machine Measurement (OMM) does. OMM technology can inspect the workpiece on its operating station by motion control and the position detection function of CNC machine tool, by which the measuring error caused by the misalignment between measuring datum and manufacturing datum can be avoided accurately. Therefore, it is a feasible way to achieve the real-time control of the manufacturing process and improve the manufacturing accuracy and efficiency. The servo axes of multi-axis CNC machine tool might be redundant for being used in OMM, which will result in that one measurement task could be done by different servo motion schemes. In addition, the map between the machine accuracy and measuring accuracy has not been found out previously. Thus, how to determine metering schemes to measure a workpiece with high accuracy and efficiency is one of the most important problems and also a hotspot for everybody. To solve this problem, a generation method of task-oriented OMM scheme is proposed. Utilizing multi-body system theory and transformation of homogeneous coordinates, a function relationship between the geometrical characteristic of workpiece as independent variables and motions of machine tool as dependent variables is established. All possible metering schemes are obtained by analyzing the solution of functional equation. Then the performance of measurement scheme can be evaluated by comparing the measuring errors of each scheme after building a mapping relationship between the machine tool volumetric errors and measuring errors. In the end, a case study was accomplished, and the correctness and efficiency of the methodology has been verified.

scholarly journals Study of Machining of Gears with Regular and Modified Outline Using CNC Machine Tools

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2913
Author(s):  
Rafał Gołębski ◽  
Piotr Boral
Keyword(s):  
Machine Tools ◽  
Coordinate Measuring Machine ◽  
Optical Microscope ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Cnc Milling ◽  
Cnc Machine ◽  
Cylindrical Gears ◽  
Measuring Machine ◽  
Five Axis

Classic methods of machining cylindrical gears, such as hobbing or circumferential chiseling, require the use of expensive special machine tools and dedicated tools, which makes production unprofitable, especially in small and medium series. Today, special attention is paid to the technology of making gears using universal CNC (computer numerical control) machine tools with standard cheap tools. On the basis of the presented mathematical model, a software was developed to generate a code that controls a machine tool for machining cylindrical gears with straight and modified tooth line using the multipass method. Made of steel 16MnCr5, gear wheels with a straight tooth line and with a longitudinally modified convex-convex tooth line were machined on a five-axis CNC milling machine DMG MORI CMX50U, using solid carbide milling cutters (cylindrical and ball end) for processing. The manufactured gears were inspected on a ZEISS coordinate measuring machine, using the software Gear Pro Involute. The conformity of the outline, the tooth line, and the gear pitch were assessed. The side surfaces of the teeth after machining according to the planned strategy were also assessed; the tests were carried out using the optical microscope Alicona Infinite Focus G5 and the contact profilographometer Taylor Hobson, Talysurf 120. The presented method is able to provide a very good quality of machined gears in relation to competing methods. The great advantage of this method is the use of a tool that is not geometrically related to the shape of the machined gear profile, which allows the production of cylindrical gears with a tooth and profile line other than the standard.

scholarly journals On the Application of Impeller in Multi Axis CNC Machine Tools

2021 ◽  
Vol 2066 (1) ◽  
pp. 012113
Author(s):  
Weiwen Ye
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Complex Surface ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Surface Processing ◽  
The Third ◽  
Machining Characteristics

Abstract Multi axis CNC machine tool has good linkage processing effect. Through the application of integral impeller in CNC machine tools, to improve the adaptability of CNC machine tools to complex surface processing parts, to improve the accuracy of multi axis CNC machine tools. The first part of this paper introduces the integral impeller and its machining characteristics; the second part introduces the basic NC machining process of integral impeller; the third part discusses the application of impeller in multi axis CNC machine tools from the creation of guide track, the simulation of integral impeller, software processing and generation. The purpose is to provide some reference for the processing and production of integral impeller.

Evaluation of Actual Geometric Tolerances Using Coordinate Measuring Machine Data

1989 ◽  
Author(s):  
W. H. ElMaraghy ◽  
Z. Wu ◽  
H. A. ElMaraghy
Keyword(s):  
Three Dimensional ◽  
Measurement Data ◽  
Simulated Data ◽  
Coordinate Measuring Machine ◽  
Optimization Techniques ◽  
Test Cases ◽  
Tolerance Zone ◽  
Geometric Tolerances ◽  
Measuring Machine

Abstract This paper focuses on the development of a procedure and algorithms for the systematic comparison of geometric variations of measured features with their specified geometric tolerances. To automate the inspection of mechanical parts, it is necessary to analyze the measurement data captured by coordinate measuring machines (CMM) in order to detect out-of-tolerance conditions. A procedure for determining the geometric tolerances from the measured three dimensional coordinates on the surface of a cylindrical feature is presented. This procedure follows the definitions of the geometric tolerances used in the current Standards, and is capable of determining the value of each geometric tolerance from the composite 3-D data. The developed algorithms adopt the minimum tolerance zone criterion. Nonlinear numerical optimization techniques are used to fit the data to the minimum tolerance zone. Two test cases are given in the paper which demonstrate the successful determination of geometric tolerances from given simulated data.

A Technique for Enhancing Machine Tool Accuracy by Transferring the Metrology Reference From the Machine Tool to the Workpiece

2006 ◽  
Vol 129 (3) ◽  
pp. 636-643 ◽  
Author(s):  
Bethany A. Woody ◽  
K. Scott Smith ◽  
Robert J. Hocken ◽  
Jimmie A. Miller
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
High Speed ◽  
Large Scale ◽  
Thermal Environment ◽  
Coordinate Measuring Machine ◽  
Shop Floor ◽  
Finished Part ◽  
Measuring Machine ◽  
Monolithic Components

High-speed machining (HSM) has had a large impact on the design and fabrication of aerospace parts and HSM techniques have been used to improve the quality of conventionally machined parts as well. Initially, the trend toward HSM of monolithic parts was focused on small parts, where existing machine tools have sufficient precision to machine the required features. But, as the technology continues to progress, the scale of monolithic parts has continued to grow. However, the growth of such parts has become limited by the inability of existing machines to achieve the tolerances required for assembly due to the long-range accuracy and the thermal environment of most machine tools. Increasing part size without decreasing the tolerances using existing technology requires very large and very accurate machines in a tightly controlled thermal environment. As a result, new techniques are needed to precisely and accurately manufacture large scale monolithic components. Previous work has established the fiducial calibration system (FCS), a technique, which, for the first time provides a method that allows for the accuracy of a coordinate measuring machine (CMM) to be transferred to the shop floor. This paper addresses the range of applicability of the FCS, and provides a method to answer two fundamental questions. First, given a set of machines and fiducials, how much improvement in precision of the finished part can be expected? And second, given a desired precision of the finished part, what machines and fiducials are required? The achievable improvement in precision using the FCS depends on a number of factors including, but not limited to: the type of fiducial, the probing system on the machine and CMM, the time required to make a measurement, and the frequency of measurement. In this paper, the sensitivity of the method to such items is evaluated through an uncertainty analysis, and examples are given indicating how this analysis can be used in a variety of cases.

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