GD&T Symmetry Symbol (Gone in 2018!) скачать в хорошем качестве

GD&T Symmetry Symbol (Gone in 2018!)

Symmetry is essentially the flat version of concentricity, and establishes a TZ composed of two parallel planes, in which the median datum points of non-cylindrical opposing features must fall. This measurement can be done for slots and cutouts, as well as tabs or parallel surfaces. The TZ will again look similar to flatness since the TZ is between two parallel planes. However, the key difference is that the symmetry is in relation to a datum plane. Just as with concentricity, symmetry is a control that is difficult to measure, requiring the calculations of as many midpoints is as realistic for a given cross section, and then again for as many cross sections as is realistic. These median points then need to be compared to a derived datum. This process is typically only practical to do with a Coordinate Measuring Machine, or CMM, which is a high precision 3D scanner. Symmetry, which controls only median points, allows for typically undesired results. For instance a slot drawn like this and controlled only for symmetry allows for variations along both horizontal axes. The part could pass inspection with an angled cut along its depth, like this or this, or an angled cut along its width, like this or this, as long as the top and bottom were symmetrically angled. Similarly, the symmetry control would also allow for symmetrically wavy cuts along either axis. Again, both of these strange cuts pass symmetry, and cost much more to inspect, while simply controlling the position of the slot, or the flatness of the two surfaces, likely would have been cheaper and more effective. Like concentricity, symmetry is almost always not the control you want to use, due to limitations in what it’s controlling, and increased costs of inspection. About us – i GET IT provides online self-paced training for engineers that is a better way to take training and share knowledge. i GET IT provides the largest library of online training and tutorials for the leading design software like AutoCAD, Autodesk Inventor, Fusion 360, NX, CATIA V5, 3DEXPERIENCE, Teamcenter, PTC Creo and SOLIDWORKS and additional topics based on the manufacturing industry. i GET IT also enables you to publish your own training content to share knowledge within your organization as a complete learning management system. Visit the i GET IT website at https://www.myigetit.com for more information. About i GET IT Platform -    • A Look at i GET IT Learning for Engineers   Why choose i GET IT Learning? -    • Why choose i GET IT Learning? | myigetit.com   _____________________________________________________ Explore the Playlists to learn – GD&T -    • Geometric Dimensioning and Tolerancing (GD&T)   3DEXPERIENCE -    • 3DEXPERIENCE - CATIA   Solidworks -    • SOLIDWORKS   PTC Creo -    • PTC Creo   ________________________________________________________ For Daily Technical Updates, follow us – Tech Blogs - https://plmtechtalk.com/ Facebook Page -   / myigetit   LinkedIn Account -   / i-get-it   Twitter Handle -   / myigetit   ________________________________________________________ For training and certification or for any query, please write us back https://support.myigetit.com/hc/en-us...