Locating Error Analysis for Computer-Aided Fixture Design and Verification

1995 ◽  
Author(s):  
Y. Rong ◽  
W. Li ◽  
Y. Bai
Keyword(s):  
Arbitrary Point ◽  
Geometric Error ◽  
Machining Process ◽  
Fixture Design ◽  
Geometric Errors ◽  
Machining Processes ◽  
Relative Slip ◽  
Locating Error ◽  
Computer Aided ◽  
Position And Orientation

Abstract In this paper, locating error effects are analyzed on geometric errors produced in machining processes, such as the parallelism, perpendicularity, and angularity of machining plane or hole surfaces. Inaccurate placement of locator positions in a fixture design may cause a change of workpiece position and orientation, and in turn, contribute to the geometric error of the products. This effect could be complex even if only the variation of one locator’s position is considered because relative slip motions between the workpiece and locators are usually allowed in fixture design. In this research, locating reference planes are established according to the positions of locators. When the locators’ positions change, the variation of these planes can be estimated. The coordinates of an arbitrary point on a machining surface of the workpiece can be determined relative to these reference planes. The coordinate variations of the points on the machining surface can be identified based on the change of locators’ positions, which is used for estimating the geometric errors produced in a machining process due to the inaccuracy of locators’ positions. This information is utilized in computer-aided fixture design and verification.

Locating error analysis and tolerance assignment for computer-aided fixture design

2001 ◽  
Vol 39 (15) ◽  
pp. 3529-3545 ◽  
Author(s):  
Y. Rong ◽  
W. Hu ◽  
Y. Kang ◽  
Y. Zhang ◽  
David W. Yen
Keyword(s):  
Error Analysis ◽  
Fixture Design ◽  
Locating Error ◽  
Computer Aided ◽  
Tolerance Assignment

Machining Accuracy Analysis for Computer-aided Fixture Design Verification

1996 ◽  
Vol 118 (3) ◽  
pp. 289-300 ◽  
Author(s):  
Y. Rong ◽  
Y. Bai
Keyword(s):  
Manufacturing Systems ◽  
Cnc Machine Tools ◽  
Machining Accuracy ◽  
Fixture Design ◽  
Accuracy Analysis ◽  
Design Verification ◽  
Cnc Machine ◽  
Machining Processes ◽  
Machining Errors ◽  
Computer Aided

This paper presents a machining accuracy analysis for computer-aided fixture design verification. While discussing the utilization of CNC machine tools and machining centers, machining errors are described in terms of deterministic and random components and analyzed on the bases of their sources, where high machining accuracy and multi-operation under a single setup become major characteristics of manufacturing systems. In machining processes, a resultant dimension may be generated in terms of several relevant dimensions. The dependency of variation among these dimensions is examined and the relationships of locating datum and machining surfaces are analyzed. Variation among linear and angular dimensions are considered. Five basic models of dimension variation relationships are proposed to estimate the machining error, where different formulas of resultant dimension variation are given for different combinations of variation among relevant dimensions. A datum-machining surface relationship graph (DMG) is developed to represent the dependent relationships. A matrix-based reasoning algorithm is designed to search for the shortest path in the DMG. Once the relationship between a specified pair of surfaces is identified, different models of corresponding relationships may be utilized to estimate the possible machining errors which can be used to compare the fixturing accuracy requirement.

A Geometric Polygon Based Computer Aided Locating Error Model for Fixture Design

2011 ◽  
Vol 4 (8) ◽  
pp. 3067-3071 ◽  
Author(s):  
Guohua Qin ◽  
Zuxi Yu ◽  
Haichao Ye ◽  
Dong Lu
Keyword(s):  
Error Model ◽  
Fixture Design ◽  
Locating Error ◽  
Computer Aided

scholarly journals Jig and fixture Redesign for Main Bearing Housing Component

2019 ◽  
Vol 5 (2) ◽  
pp. 64
Author(s):  
Asep Indra Komara
Keyword(s):  
Repair Process ◽  
Machining Process ◽  
Fixture Design ◽  
Product Analysis ◽  
Machining Processes ◽  
Main Bearing ◽  
Process Sequence ◽  
Measurement Results ◽  
Housing Component ◽  
Machine Analysis

Main bearing housing is one of the gear transmission product components. The production process of this component needs to be repaired. The repair process is carried out on the fixture construction used today. Redesign is done as one of the solution to improve of the existing fixture design. The measurement results of the products that are machined with the existing fixture are still not in accordance with the requirements of the released product drawing. This is thought to occur because of an error in determining the operating procedur of the machining process that has an impact on the design of the fixture, especially in determining the reference to each machining processes carried out. Therefore, the new fixture needs to be designed so that the resulting product can fit the drawing demands. The repair process is carried out through a gradual study that refers to the methodology of the SME in order to be systematic and structured. Each stage of the design is carried out in detail starting from the study of product analysis, machining analysis, machine analysis, operator analysis and economic analysis. Based on the results of a product analysis study, a new machining process sequence has been produced. The new fixture design has been produced based on this sequence of machining processes. Based on the results of the study, it shows that the results of the redesign of the fixture repair show the conditions that are in accordance with the demands of the product images of the main bearing housing

Tool path error prediction of a five-axis machine tool with geometric errors

2002 ◽  
Vol 216 (5) ◽  
pp. 697-712 ◽  
Author(s):  
Y A Mir ◽  
J R R Mayer ◽  
C Fortin
Keyword(s):  
Machine Tool ◽  
Computer Aided Design ◽  
Tool Path ◽  
Kinematic Model ◽  
Dimensional Accuracy ◽  
Geometric Error ◽  
Geometric Errors ◽  
Computer Aided Process Planning ◽  
Computer Aided ◽  
Five Axis

Predicting the actual tool path of a machine tool prior to machining a part provides useful data in order to ensure or improve the dimensional accuracy of the part. The actual tool path can be estimated by accounting for the effect of the machine tool geometric error parameters. In computer aided design/computer aided manufacture (CAD/CAM) systems, the nominal tool path [or CL (cutter location) data] is directly generated from the curves and surfaces to be machined and the errors of the machine tool are not considered. In order to take these errors into consideration, they must first be identified and then used in the machine tool forward kinematic model. In this paper a method is presented to identify the geometric errors of machine tools and predict their effect on the tool-tip position. Both the link errors (position-independent geometric error parameters) and the motion errors (position-dependent geometric error parameters) are considered. The nominal and predicted tool paths are compared and an assessment is made of the resulting surfaces with respect to the desired part profile tolerance. A methodology is also suggested to integrate this tool within a CAD/CAPP (computer aided process planning)/CAM environment.

Studying The Effect of a New Mixed Cutting Fluid on Surface Roughness

2020 ◽  
Vol 38 (11A) ◽  
pp. 1593-1601
Author(s):  
Mohammed H. Shaker ◽  
Salah K. Jawad ◽  
Maan A. Tawfiq
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Cutting Parameters ◽  
Machining Process ◽  
Cutting Fluid ◽  
Depth Of Cut ◽  
Cutting Fluids ◽  
Machining Processes ◽  
Dry Cutting ◽  
Cutting Speeds

This research studied the influence of cutting fluids and cutting parameters on the surface roughness for stainless steel worked by turning machine in dry and wet cutting cases. The work was done with different cutting speeds, and feed rates with a fixed depth of cutting. During the machining process, heat was generated and effects of higher surface roughness of work material. In this study, the effects of some cutting fluids, and dry cutting on surface roughness have been examined in turning of AISI316 stainless steel material. Sodium Lauryl Ether Sulfate (SLES) instead of other soluble oils has been used and compared to dry machining processes. Experiments have been performed at four cutting speeds (60, 95, 155, 240) m/min, feed rates (0.065, 0.08, 0.096, 0.114) mm/rev. and constant depth of cut (0.5) mm. The amount of decrease in Ra after the used suggested mixture arrived at (0.21µm), while Ra exceeded (1µm) in case of soluble oils This means the suggested mixture gave the best results of lubricating properties than other cases.

A state-of-art review on chatter and geometric errors in thin-wall machining processes

2021 ◽  
Vol 68 ◽  
pp. 454-480
Author(s):  
Ge Wu ◽  
Guangxian Li ◽  
Wencheng Pan ◽  
Izamshah Raja ◽  
Xu Wang ◽  
...  
Keyword(s):  
Thin Wall ◽  
Geometric Errors ◽  
Machining Processes ◽  
State Of Art

scholarly journals Temperature monitoring in the subsurface during single lip deep hole drilling

2020 ◽  
Vol 87 (12) ◽  
pp. 757-767
Author(s):  
Robert Wegert ◽  
Vinzenz Guski ◽  
Hans-Christian Möhring ◽  
Siegfried Schmauder
Keyword(s):  
Cutting Parameters ◽  
Drill Hole ◽  
Machining Process ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Machining Processes ◽  
Deep Hole Drilling ◽  
Feed Force ◽  
Cutting Zone

AbstractThe surface quality and the subsurface properties such as hardness, residual stresses and grain size of a drill hole are dependent on the cutting parameters of the single lip deep hole drilling process and therefore on the thermomechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. In this contribution, the main objectives are the in-process measurement of the thermal as-is state in the subsurface of a drilling hole by means of thermocouples as well as the feed force and drilling torque evaluation. FE simulation results to verify the investigations and to predict the thermomechanical conditions in the cutting zone are presented as well. The work is part of an interdisciplinary research project in the framework of the priority program “Surface Conditioning in Machining Processes” (SPP 2086) of the German Research Foundation (DFG).This contribution provides an overview of the effects of cutting parameters, cooling lubrication and including wear on the thermal conditions in the subsurface and mechanical loads during this machining process. At first, a test set up for the in-process temperature measurement will be presented with the execution as well as the analysis of the resulting temperature, feed force and drilling torque during drilling a 42CrMo4 steel. Furthermore, the results of process simulations and the validation of this applied FE approach with measured quantities are presented.

scholarly journals Influence of a closed-loop controlled laser metal wire deposition process of S Al 5356 on the quality of manufactured parts before and after subsequent machining

2021 ◽  
Author(s):  
Dina Becker ◽  
Steffen Boley ◽  
Rocco Eisseler ◽  
Thomas Stehle ◽  
Hans-Christian Möhring ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Closed Loop ◽  
Deposition Process ◽  
Metal Wire ◽  
Machining Process ◽  
Machining Processes ◽  
Initial State ◽  
Additive Process ◽  
Shape Accuracy ◽  
Loop Control

AbstractThis paper describes the interdependence of additive and subtractive manufacturing processes using the production of test components made from S Al 5356. To achieve the best possible part accuracy and a preferably small wall thickness already within the additive process, a closed loop process control was developed and applied. Subsequent machining processes were nonetheless required to give the components their final shape, but the amount of material in need of removal was minimised. The effort of minimising material removal strongly depended on the initial state of the component (wall thickness, wall thickness constancy, microstructure of the material and others) which was determined by the additive process. For this reason, knowledge of the correlations between generative parameters and component properties, as well as of the interdependency between the additive process and the subsequent machining process to tune the former to the latter was essential. To ascertain this behaviour, a suitable test part was designed to perform both additive processes using laser metal wire deposition with a closed loop control of the track height and subtractive processes using external and internal longitudinal turning with varied parameters. The so manufactured test parts were then used to qualify the material deposition and turning process by criteria like shape accuracy and surface quality.

Modeling and Identification of Geometric Error Based on Screw Theory

2014 ◽  
Vol 941-944 ◽  
pp. 2219-2223 ◽  
Author(s):  
Guo Juan Zhao ◽  
Lei Zhang ◽  
Shi Jun Ji ◽  
Xin Wang
Keyword(s):  
Machine Tool ◽  
Laser Interferometer ◽  
Screw Theory ◽  
Geometric Error ◽  
New Method ◽  
Geometric Errors ◽  
Volumetric Error ◽  
B Spline ◽  
The Individual

In this paper, a new method is presented for the identification of machine tool component errors. Firstly, the Non-Uniform Rational B-spline (NURBS) is established to represent the geometric component errors. The individual geometric errors of the motion parts are measured by laser interferometer. Then, the volumetric error for a machine tool with three motion parts is modeled based on the screw theory. Finally, the simulations and experiments are conducted to confirm the validity of the proposed method.

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