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Unformatted text preview: signer. As a result, the contribution chart is consulted again to adjust another tolerance in the dimensional chain. The critical contributor is now FE3 (contribution of 13.89%) so the tolerance te and tf are reassigned values (see section 3 in table I, H11 and h8) and the corresponding FR finally increases to ±1.032. After three iterations, the FR computed (±1.032) by the unified model is in line with the designer’s specification of ±1mm. The corresponding tolerance values shown in the last section (section 3) of table I are then accepted accordingly. 6. CONCLUSION A unified Jacobian-Torsor model with intervals has been used to allocate tolerances in a dimensional chain. Through a numerical (percentage contribution) and graphical (chart, histogram) approach, the proposed methodology guides the designer into choosing the proper tolerances. The percentage contribution chart tells the designer how each tolerance has contributed to the total FR. Once these contributions have been identified, the designer proceeds to modify the most critical tolerance zones so as to respect the Functional...
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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