Can ISO GPS and ASME Tolerancing Systems Define the Same Functional Requirements?

Geometrical tolerances are defined in the ISO Geometrical Product Specification system that is used worldwide, but on the other hand, the ASME Y14.5 standard is used in American companies to define how far actual parts may be away from their nominal geometry. This paper aimed to investigate whether specifications defining acceptable geometrical deviations in one system can be transformed to specifications in the other system. Twelve selected cases are discussed in the paper. Particularly, two cases of size tolerance, three cases of form tolerances, one case of orientation tolerance, four cases of position tolerance (including position tolerance with MMR for the pattern of five holes) and, finally, two cases of surface profile tolerance (unequally disposed tolerance zone and dynamic profile tolerance). The issue is not only in the several different symbols and a set of different defaults, but also in the different meanings and different application contexts of some symbols that have the same graphical form. The answer to the question raised in the paper title is yes for the majority of indications specified according to ASME Y14.5 when new tools from the 2017 edition of ISO 1101 are applied.

Micro-ECM of the Aerodynamic Surface Understating

This paper demonstrates that 18 μm deep surface understating with a tolerance of 4.5 μm and a roughness Ra=0.4 μm can be produced to the required accuracy by electrochemical die-sinking if configured appropriately.Theoretical analysis shows that the bottom profile error can be presented as a superposition of the errors of surface alignment (non-parallel bottom) and shape (non-flat bottom). In this case, the alignment error accounts for a greater part of the size tolerance (3 μm out of 4.5 μm). This is why the attainment of desired accuracy revolves around the development, analysis, and assessment of ways to reduce this error.

Research on Redesign and Manufacturing of an Automatic Roll Cutting Machine

Textile-and-garment industry is one of the largest economic sectors in Vietnam, with 4000 enterprises and a turnover of 20 billion USD/year. Therefore, designing and manufacturing are essential tasks for roll fabric cutting machines to serve the textile and garment industry. First of all, theoretical calculations are formulated for an automatic roll cutting machine. Then, simulations are conducted by a combination of MITcalc and Catia software. A prototype of a fabric cutting machine is manufactured and experiments are implemented. The experimental results show that the machine stably works and overcomes the disadvantages of the popular cutting machines with the core-free roll on the market. The results also found that the size tolerance is achieved about ± 0.5 mm, and this ensures good working quality. The designed machine has a significant contribution to the textile and garment area in decreasing the cost of the cutting process. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

Study on the Extraction Simulation of the Cylindrical Features

The extraction simulation method and theory of cylindrical components were promoted in this paper. According to the manufacturing principle of the cylindrical components, the main influence factors of their precision manufacturing were analyzed, and their extraction models of cylindrical features were built under the analysis of the errors of the slideway and the spindle as well as the parallelism error between the slideway and the spindle rotary axis. The determination principle of modeling parameters of cylindrical features was studied. According to the extraction strategies of the roundness profiles, generatrix profiles, birdcage profile, and single spiral profile, some cylindrical features were simulated by using the established models, and their corresponding global sizes, calculated sizes, and form errors were evaluated and compared. The simulation experiments showed that the simulation models can meet the needs for the research of the relationship among the size tolerance, the form tolerance, the waviness, and the roughness, and can be taken as the theoretic base for the error budgets of the slideway and the rotation spindle in the design of precision machine tools.

ANALYSIS OF THE ACCURACY OF ELECTROMECHANICAL MICROMACHINING

The achieved accuracy in the electrochemical performance of understatement with a depth of 18 mcm with a tolerance of 4.5 mcm in a flow-through interelectrode channel is studied. The primary error of the size. The allowed absolute and relative errors of processing mode parameters are set. Keywords: UNDERSTATEMENT, ELECTROCHEMICAL MACHINING, ERROR, PRECISION SIZE, TOLERANCE, PROCESSING MODE. [email protected]

Разработка эталона для поверки системы автоматизированной морфометрии клинических изображений новообразований кожи

The article is devoted to the technological and metrological features of creating a measurement standard for calibration and verification of the system of automated morphometry of skin neoplasms images in the diagnose skin melanoma. The requirements for the measurement standard has been formulated. The technological process of manufacturing the measurement standard based on thermal-transfer printing has been developed. The main technological parameters of printing has been defined: the temperature should be 180ºC, the image transfer speed should be 2.0 sec/inch. The color difference in the manufacture of the standard is not more than ΔE*ab=2.5 (CIELAB 1976), the image size tolerance is not more than 0.02%.

Temporal contiguity training does not affect size-tolerant representations in object-selective cortex

The human visual system has a remarkable ability to reliably identify objects across variations in appearance, such as variations in viewpoint, lighting and size. Here we used fMRI in humans to test whether temporal contiguity training with natural and altered image dynamics can respectively build and break neural size tolerance for objects. Participants (N = 23) were presented with sequences of images of “growing” and “shrinking” objects. In half of the trials, the object also changed identity when the size change happened. According to the temporal contiguity hypothesis, and studies with a similar paradigm in monkeys, this training process should alter size tolerance. After the training phase, BOLD responses to each of the object images were measured in the scanner. Neural patterns in LOC and V1 contained information on size, similarity and identity. In LOC, the representation of object identity was partially invariant to changes in size. However, temporal contiguity training did not affect size tolerance in LOC. Size tolerance in human object-selective cortex is more robust to variations in input statistics than expected based on prior work in monkeys supporting the temporal contiguity hypothesis.