Hi y'all,
I have a sort of dilemma.
In our mechanical tem, there are designers like me who are convinced that top-down design (skeleton models) is the best way to use Pro/Engineer. Interfaces between parts are modeled in the skeleton model first and then in the parts,attaching the features to those of the skeleton model. This way, every interface has to bedimensionned once and all parts sharing it are modified accordingly, eliminating the risk of incoherence. Therefore, every feature is dimensionned to the nominal dimension. A shaft, for example, has a nominal diameter of 10 mm with a tolerance of +0, -0.1. The hub, also modeled to the 10 mm nominal value, has a tolerance of +0.1, +0.2. This has always worked very well for us as long as we had 2D drawings where the tolerances are displayed.
Unfortunately, there are some other peoplewho think more in terms of manufacturing and whosay that our 3D models should be modeled to the dimension in the middle of the tolerance range. Then, my shaft would have a diameter of 9.95
I have a sort of dilemma.
In our mechanical tem, there are designers like me who are convinced that top-down design (skeleton models) is the best way to use Pro/Engineer. Interfaces between parts are modeled in the skeleton model first and then in the parts,attaching the features to those of the skeleton model. This way, every interface has to bedimensionned once and all parts sharing it are modified accordingly, eliminating the risk of incoherence. Therefore, every feature is dimensionned to the nominal dimension. A shaft, for example, has a nominal diameter of 10 mm with a tolerance of +0, -0.1. The hub, also modeled to the 10 mm nominal value, has a tolerance of +0.1, +0.2. This has always worked very well for us as long as we had 2D drawings where the tolerances are displayed.
Unfortunately, there are some other peoplewho think more in terms of manufacturing and whosay that our 3D models should be modeled to the dimension in the middle of the tolerance range. Then, my shaft would have a diameter of 9.95