Easier to build easier to assemble, right? Well not in this case. All of the designs I reviewed were delineated in simple limit tolerances of plus and minus .020. Dimension and tolerances were not arranged with respect to functional or interfacing surfaces. Ultimately, we did change the agenda to review the importance of properly defining mechanical tolerancing on engineering drawings.
DFM/DFMA training did help my customer understand their manufacturing requirements but the followup ASME GD&T training helped the designers to define tolerances and tolerance relationships that were both manufacturing centric and assured that true interchangeable part and assemblies were manufactured.
What is Geometric Dimensioning and Tolernacing?
Geometric Dimensioning and Tolerancing (GD&T) is a language used on mechanical engineering drawings and is composed of symbols that define specific geometric and tolerance requirements for features and assemblies.
- Provides a clear and concise technique for defining a reference coordinate system (datum's) on a component or assembly to be used throughout the manufacturing and inspection processes.
- Proper application of geometric dimensioning closely dovetails accepted and logical mechanical design process and design for manufacturing considerations.
- Geometric dimensioning dramatically reduces the need for drawing notes to describe complex geometry requirements on a component or assembly by the use of standard symbology that accurately and quickly defines design, manufacturing and inspection requirements.
- GD&T concepts such as MMC (maximum material condition) when applied properly will facilitate and simplify the design of cost saving functional check gages, manufacturing fixtures and jigs.
No comments:
Post a Comment