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Unformatted text preview: The role of this step is to compare the result of FR values obtained in step 4 with the design specifications imposed in the first step. If the assigned FR sought by the designer is not met, the tolerances of critical FE need to be reassigned using tolerances allocation techniques. Calculated FR values can then be adjusted to meet the designer’s intent by tuning the values (equation 4) of the corresponding critical tolerances (largest or smallest contributors). So, if the calculated FR is smaller than the imposed FR, then, by augmenting the smallest contributor tolerance obtained in step 4, we increase the value of the calculated FR. However, if the calculated FR is greater than the imposed FR, then we need to decrease the calculated FR. This can be done through a reduction of the biggest contributor tolerance. Of course it then becomes important to check the values of the manufacturing tolerances on the vendorsupplied parts because these can obviously not be modified. The procedure is repeated until the calculated FR falls within specification. The steps illustrated above describe a comprehensive method for creating and validating assembly tolerances. The procedure can be a...
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This note was uploaded on 08/03/2010 for the course DD 1234 taught by Professor Zczxc during the Spring '10 term at Magnolia Bible.
- Spring '10
- The Land