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Applying SMED to Internal Operations
Published in Shigeo Shingo, Andrew P. Dillon, A Revolution in Manufacturing: The SMED System, 2019
Shigeo Shingo, Andrew P. Dillon
F Precision Instruments is a manufacturer of metal dies for die casting and plastic molding machines. While drawings often showed measurements from a center line, they did not show measurements from a reference plane used in processing. For this reason, it was necessary to place the raw material on the surface plate and then mark off the locations of holes or parts to be cut. The material was first leveled with a spirit level, and then supported with a jack.The height of the upper surface was measured with a height gauge.Drawing values were consulted, the distance to the center position calculated, and the center marked off with a height gauge. Allowance was made, of course, for the top and bottom cutting margins.With this center line as a reference, the positions of holes and sections to be cut were marked off successively. By using the drawings, it was then possible to calculate the values for setting the center line.
Marking out
Published in Roger Timings, Engineering Fundamentals, 2007
The vernier height gauge was introduced in Chapter 6 as a measuring instrument. It is also used for scribing lines parallel to a datum surface in a similar manner to a scribing block. However, unlike a scribing block that has to be set to a separate steel rule, a vernier height gauge has a built-in main scale and vernier scale so that it can be set to a high degree of accuracy. The setting and reading of vernier scales was described in Chapter 6. The height gauge is fitted with a removable, sharpened nib. This is set to the required height by the scales provided. To scribe a line parallel to the datum surface, as shown in Fig. 7.7, the following procedure is used.
Tolerancing
Published in Ken Morling, Stéphane Danjou, Geometric and Engineering Drawing, 2022
Flatness is measured with a height gauge running across the toleranced surface. For that, it is essential to make sure that the reference for the gauge is in parallel. Nowadays, coordinate measuring machines (CMM) are able to compare the measured surface with a virtual plane. A flatness specification is used, for example, for surfaces forming a seal with a mated part or for ensuring a uniform wear of a surface.
Handheld pocket-size Fourier transform profilometry using projector-enabled smartphone
Published in The Imaging Science Journal, 2020
Joewono Widjaja, Sangchai Paichit, Jerasak Kamonboon, Jaroon Wongjaren
After reconstructing the height profiles from 50 columns of the deformed grating patterns by using Equation (4), they were averaged. Figure 5 shows a comparison of the average height of the experimentally reconstructed prism profiles using the CFTP, the NPSFTP and the direct contact measurement, respectively. The latter measurement was done by using a Moore and Wright height gauge (MW190-30DBL), whose resolution and accuracy are 0.01 and 0.04 mm, respectively. The circle symbol corresponds to the height measurement by the direct height gauge measurement, while the dashed and the solid lines denote the reconstruction results using the CFTP and the NSPFTP, respectively.