scholarly journals The Unpredictable Errors of Micro Tactile Metrology – Factors Affecting Stylus tip Contamination

2013 ◽  
Vol 13 (6) ◽  
pp. 305-310 ◽  
Author(s):  
P. Kinnell ◽  
R. Habeb
Keyword(s):  
Surface Finish ◽  
Large Body ◽  
Coordinate Measuring Machine ◽  
Probe Design ◽  
Sample Material ◽  
Factors Affecting ◽  
Material Type ◽  
Measuring Machine ◽  
Accuracy And Repeatability

Abstract In 3D tactile micro-metrology the contamination of probing devices is a major problem that affects the accuracy and repeatability of measured dimensions. Despite a large body of research in the field of micro CMM and micro probe design there is limited research which has been done so far to explain and tackle this problem. In this work, experimental probing on a range of materials using a micro coordinate measuring machine was conducted to investigate the mechanism of stylus tip contamination. In addition the effects of surface finish on the build-up of stylus tip contamination were also studied. The results provide practitioners with guidelines which allow for the likely build-up of stylus tip contamination to be minimized based on sample material type and surface finish.

Computer-Aided Coordinate Metrology

1993 ◽  
Author(s):  
Hong-Tzong Yau ◽  
Chia-Hsiang Menq
Keyword(s):  
Three Dimensional ◽  
Coordinate Measuring Machine ◽  
Computer Integrated Manufacturing ◽  
Integrated Manufacturing ◽  
Coordinate Metrology ◽  
Cad Cam ◽  
Measuring Machine ◽  
Three Dimensional Coordinate ◽  
Inspection Machine ◽  
Accuracy And Repeatability

Abstract Three-dimensional coordinate metrology has gained much attention in recent years. On one hand, the accuracy and repeatability of a coordinate measuring machine (CMM) are approaching the sub-micron level. On the other hand, there is hardly any part that exists of which the dimensions cannot be measured with a CMM. This paper presents the recent development and applications in three-dimensional coordinate metrology. The emphasis has been placed in the utilization of computers and integration with CAD/CAM systems. Three important technologies, namely, CAD-directed inspection, three-dimensional optimal match, and reverse engineering are presented and discussed. With computers and CAD/CAM support, three-dimensional coordinate metrology has become an active part of the computer-integrated manufacturing (CIM). Its versatility and high degree of automation have made the CMM a universal inspection machine for quality control of manufactured parts in computer integrated manufacturing.

Development Trends and Present Situation about the Error Detection of Plane Thread of Three-Jaw Chuck

2012 ◽  
Vol 241-244 ◽  
pp. 36-41
Author(s):  
Rui Ma ◽  
Chang Jing Sun
Keyword(s):  
Error Detection ◽  
Coordinate Measuring Machine ◽  
Present Situation ◽  
Secondary Development ◽  
Detection Level ◽  
Development Trends ◽  
Factors Affecting ◽  
Machining Precision ◽  
Measuring Machine ◽  
Main Factors

Analyzed the main factors affecting machining precision of three jaw self-centring chuck with plane thread. Reviewed the states of detection about the error of three-jaw chuck with plane thread. For the shortcomings of the detection in accuracy and efficiency, proposed development trends of using coordinate measuring machine, based on the secondary development of the software to adapt to the fast and batch detection about the error of different specifications of chucks with plane thread, which has a guiding significance to enhance the error detection level of the plane thread and to ensure its precision.

An Optimization Strategy for Maximizing Coordinate Measuring Machine Productivity, Part 1: Quantifying the Effects of Operating Speed on Measurement Quality

1995 ◽  
Vol 117 (4) ◽  
pp. 601-609 ◽  
Author(s):  
S. D. Jones ◽  
A. Galip Ulsoy
Keyword(s):  
Coordinate Measuring Machine ◽  
Operating Speed ◽  
Production Operation ◽  
Optimization Strategy ◽  
Factors Affecting ◽  
Measurement Quality ◽  
Machine Productivity ◽  
Study Results ◽  
Dimensional Measurements ◽  
Measuring Machine

The ability to quickly obtain precise dimensional information about manufactured parts is vital for any successful mass production operation. Coordinate Measuring Machines (CMMs) can be used to obtain dimensional measurements, but the effects of structural vibrations often limit the speed at which measurements can be obtained. In this, the first of two papers, the effects of operating speed on CMM measurement quality are illustrated, and the factors affecting measurement speed are then analyzed through an Analysis of Variance (ANOVA) study. Results of the illustration and ANOVA show that as operating speed increases, the quality of the measurements obtained decreases, and that the individual axes of the prismatic CMM structure experimentally evaluated react differently to measuring speeds. Also given are results that show the trade-off between measurement time and quality and indicate the existence of optimal operating speeds for certain values of measurement quality. A model is then developed that describes the relationship between measurement speed and measurement quality for use in the optimization strategy presented in Part 2 of this paper.

scholarly journals Evaluation of dimensional accuracy of dental bridges manufactured with conventional casting technique and CAD/CAM system with Ceramill Sintron blocks using CMM

2018 ◽  
Vol 12 (4) ◽  
pp. 264-271 ◽  
Author(s):  
Alireza Izadi ◽  
Fariborz Vafaee ◽  
Arash Shishehian ◽  
Ghodratollah Roshanaei ◽  
Behzad Fathi Afkari
Keyword(s):  
Reference Model ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Three Dimensions ◽  
Casting Technique ◽  
Dimensional Changes ◽  
Conventional Casting ◽  
Cad Cam ◽  
Milling Method ◽  
Measuring Machine

Background. Recently, non-presintered chromium-cobalt (Cr-Co) blocks with the commercial name of Ceramill Sintron were introduced to the market. However, comprehensive studies on the dimensional accuracy and fit of multi-unit frameworks made of these blocks using the coordinate measuring machine (CMM) are lacking. This study aimed to assess and compare the dimensional changes and fit of conventional casting and milled frameworks using Ceramill Sintron. Methods. A metal model was designed and scanned and 5-unit frameworks were fabricated using two techniques: (I) the conventional casting method (n=20): the wax model was designed, milled in the CAD/CAM machine, flasked and invested; (II) the milling method using Ceramill Sintron blocks (n=20): the wax patterns of group 1 were used; Ceramill Sintron blocks were milled and sintered. Measurements were made on the original reference model and the fabricated frameworks using the CMM in all the three spatial dimensions, and dimensional changes were recorded in a checklist. Data were analyzed with descriptive statistics, and the two groups were compared using one-way ANOVA and Tukey test (α=0.05). Results. The fabricated frameworks in both groups showed significant dimensional changes in all the three dimensions. Comparison of dimensional changes between the two groups revealed no significant differences (P>0.05) except for transverse changes (arch) that were significantly greater in Ceramill Sintron frameworks (P<0.05). Conclusion. The two manufacturing processes were the same regarding dimensional changes and the magnitude of marginal gaps and both processes resulted in significant dimensional changes in frameworks. Ceramill Sintron frameworks showed significantly greater transverse changes than the conventional frameworks.

scholarly journals The Influence of Automated Machining Strategy on Geometric Deviations of Machined Surfaces

2021 ◽  
Vol 11 (5) ◽  
pp. 2353
Author(s):  
Ján Varga ◽  
Teodor Tóth ◽  
Peter Frankovský ◽  
Ľudmila Dulebová ◽  
Emil Spišák ◽  
...  
Keyword(s):  
Control System ◽  
Surface Quality ◽  
Coordinate Measuring Machine ◽  
Geometric Tolerance ◽  
Geometric Tolerances ◽  
Significant Difference ◽  
Geometric Deviations ◽  
Measuring Machine ◽  
Overlap Parameter ◽  
Total Average

This paper deals with various automated milling strategies and their influence on the accuracy of produced parts. Among the most important factors for surface quality is the automated milling strategy. Milling strategies were generated from two different programs, CAM system SolidCAM, with the help of workshop programming in the control system Heidenhain TNC 426. In the first step, simulations of different toolpaths were conducted. Using geometric tolerance is becoming increasingly important in robotized production, but its proper application requires a deeper understanding. This article presents the measurement of selected planes of robotized production to evaluate their flatness, parallelism and perpendicularity deviations after milling on the coordinate measuring machine Carl Zeiss Contura G2. Total average deviations, including all geometric tolerances, were 0.020 mm for SolidCAM and 0.016 mm for Heidenhain TNC 426. The result is significantly affected by the flatness of measured planes, where the overlap parameter of the tools has a significant impact on the flatness of the surface. With interchangeable cutter plate tools, it is better to use higher overlap to achieve better flatness. There is a significant difference in production time, with SolidCAM 25 min and 30 s, and Heidenhain 48 min and 19 s. In accordance with these findings, the SolidCAM system is more suitable for production.

scholarly journals Experimental study on the factors affecting torque of beam-type implant torque wrenches

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hiroki Shiba ◽  
Yuji Sato ◽  
Junichi Furuya ◽  
Tokiko Osawa ◽  
Akio Isobe ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Leading Edge ◽  
Beam Width ◽  
Factors Affecting ◽  
Tightening Force ◽  
Torque Wrench ◽  
Screw Breakage ◽  
Beam Type ◽  
Accuracy And Repeatability ◽  
Excellent Accuracy

Abstract Background Screw breakage and loosening are the most common mechanical complications associated with implant treatment, and they may occur due to excess or inadequate screw tightening torque. When fastening and fixing the implant superstructure, screws are tightened using a torque wrench, which is essential for an accurate tightening force. However, the characteristics of the torque wrench have not been fully verified. Therefore, we aimed to clarify the factors affecting the torque with a focus on beam-type torque wrenches, which are the main types of wrenches. Methods The torque values generated by beam-type torque wrenches from eight manufacturers were measured using a torque gauge. To investigate the influence of the location of the beam relative to the scale, measurements were performed with a scale aligned with the trailing edge, center, and leading edge of the beam respectively. Additionally, measurements were taken at 90°, 60°, and 30° to examine the effect of the angle at which the examiner read the torque value. Under each condition, a single examiner applied the recommended torque to each manufacturer's screws five times in a clockwise direction. The average measured torque, standard deviation, bias, and coefficient of variation were calculated and compared accordingly. Results Wrenches from six manufacturers demonstrated excellent accuracy for measurements at the center of the beam (bias within ± 4%). For measurements at 90°, equipments from five manufacturers displayed excellent accuracy (bias within ± 7%), and seven showed excellent repeatability (coefficient of variation ≤ 2%). Conclusion The scale should be aligned with the center of the beam and read from 90° while using a torque wrench. The accuracy and repeatability torques generated by the wrenches differed according to the manufacturer, scale width, scale line width, beam width, and distance between the scale and beam center. Based on these results, we suggest that a torque wrench must be selected after determining the difference in the structure of the torque wrench.

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