Understanding variation caused on account of Geometric Tolerances
As a designer, you often face difficulties visualizing the variation caused by Geometric (GD&T) tolerances.
We bring you this free multimedia guide to overcome this difficulty. This guide will help you evaluate tolerance stacks, and make your designs more predictable.
In mechanical assemblies, individual components are assigned dimensions and tolerances. When the individual components go into an assembly, component tolerances interact to produce a resultant variation on the assembly. The impact of component tolerances on assemblies is called Tolerance Stackup. A structured analysis of Tolerance Stacks is Dimensional Variation Analysis (DVA).
CAD-based DVA softwares are a pain!
You probably have at hand several advanced DVA software to perform DVA. You must have already realized that these software programs require an underlying 3D CAD model. This 3D CAD model has to be built with very strict Datum progression definitions and GD&T Tolerances. Any variation in such definitions and errors of assumptions may lead to a wrong DVA. Pre-analysis model preparation becomes a very tedious and time-consuming process.
Also, 90% of the DVA cases do not require 3D analysis! Majority of the DVA cases you would encounter are Linear ones. You will therefore find that visualization and spreadsheet-based analysis is usually a reliable, inexpensive and the quickest method to do DVA.
This multimedia guide enables you to visualize variation caused by Geometric tolerances. Navigate through the various cases of Geometric Tolerances using the menus provided on the left. DVA is always focused on evaluating a target Gap. The cases shown here address such target Gaps.