Contributions for Selected Stackups
In the Contributions area in the Summary table and in the Details table, you can view a list of dimensions and tolerances that impact the Stackup including their relative contributions which are sorted from the largest to the smallest contributor.
Each row contains one of the following combinations:
• The part name and dimension name for standard dimensions.
• The part name, name of the feature being controlled, and the feature control frame including referenced datum features.
In the Stackup Details table, the feature control frame and the basic dimension between the controlled feature and the datum feature are in the same row.
• The Datum Shift contributors from the datum features being referenced and Maximum or Least Material Boundary—(MMB or LMB). In the row, the datum name and the name of the feature that is being controlled are included.
• The Assembly Shift contributors representing clearances between parts along with the names of the features between which the shift occurs.
You can use the information about which features/dimensions are the biggest contributors to the Stackup variation to make some decisions about which tolerances can be adjusted to achieve your cost and quality goals.
• Items with the lowest contributions are good candidates for saving cost by loosening the tolerances. This is because changes to these tolerances will have a relatively small impact on the results.
• Items with the highest contributions are candidates are good candidates for improving the quality metrics by tightening the tolerances. This is because changes to these tolerances will have a relatively large impact on the results.