Companies are transferring digital data and the official master document is no longer a physical master but the 3D CAD model digital format.
The advantages of this situation are clear to everybody: less paper, quicker transfer of data using internet, and lots of other flashy advantages. When we talk about the 3D models, of course, one of the main advantage all of us indicate is that a 3D model is complete and has all the needed information; there is no need for interpretation such as when using 2D drawing. This is true, and having a 3D model puts manufacturers in a more competitive situation. There are, however, some hidden dangers that many engineers are ignoring for different reasons.
One big danger is related to changes that are happening to a digital model without notice. How could a 3D digital model be changed without notice? There are lot of situations where this could happen, and it could happen much more frequently than what you could think.
The most common unexpected change happens when a 3D digital model is transferred from one system to another - even with using the same software. Sometimes software updates also bring changes to algorithms that will interpret a model defined with a previous version in a different way. These are changes that normally happen between different software as each system could define part of the models using different type of mathematics. In general, this does not result in big changes, but if we add up multiple transfer errors of microns, it could easily become large enough to be noticed or to make the part fail quality assurance tests.
Another situation where unexpected changes happen is data translation, especially when neutral file formats are used. Every system reads and writes these files in the most convenient way for themselves, so a cylinder written in IGES could be represented in lot of different ways. When it is read back it could result with a different topology, even if it is still a cylinder. But these changes are usually small changes that are allowable inside the tolerances. But today, files are easily transferred from one department to another and then from one supplier to another. In most cases, each location is reading the file in their system and exporting it again-with a risk of gradually changing the model to an incorrect state.
Another hidden danger is given inside parametric systems. In this type of software, the user can easily make changes to a complex model; most engineers are happy with this system. What could happen, however, is that the designer who is applying a small change would not notice that constrains and parameters are also applying that change to an area of the model that should not be changed. The user simply forgets the relationships of the parametric data.
If you understand these 'technology failures' or 'human errors', you can see how often a model could fully get out of control. And with its lack of quality control, it brings with it errors in production where it becomes even more difficult to pinpoint the cause of the error.
Kubotek has produced a software called Validation Tool that allows users to easily validate and compare models in order to be sure no changes were applied to the Model Digital Definition of the part they are producing. The software can be applied in any situation where the risks of changes exist: data translations, software migrations, revision changes and simple human error.
Validation Tool can completely certify the quality of the model versus the master in a few simple steps. The user is able to check dynamically where changes happened in order to apply the needed correction before the part is produced.
Quality managers can apply this validation through the supply chain, but also inside the same company where data is transferred between different software.
Project managers can use Validation Tool to document revision changes, avoiding any 'forgotten' changes.
Companies who are working as suppliers can validate different versions of files received from their customers in order to be sure they get all the changes applied (even if they are not documented).
Kubotek Validation Tool is Windows-based and can read native files of most of the CAx systems and a wide list of neutral file formats. This makes it independent from any CAD system and usable in any environment.
Kubotek used the technologies developed through the years for its CAD system, KEYCREATOR (previously known as CADKEY). Technologies and algorithms such as Face Logic, pattern recognition, and editable, pure geometry allows the system to give answers in minutes with very high precision.
Luca Cariglia is with Kubotek Europe srl, Cosostabissara, Italy. www.kubotekeurope.com
