Rev. 1/2010 Tolerance Stack-Up Analysis - ttc …

1 Tolerance Stack-Up Analysis Rev. 1/2010 Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Finding the mean:Calculate the sum and the difference between theMMC and LMC and divide each by two Maximum Material Condition (MMC): Themaximum material condition of a feature of sizeis the maximum amount of material within thestated limits of size. For example, the maximumshaft diameter or the minimum hole diameter. Least Material Condition (LMC): The leastmaterial condition of a feature of size is the leastamount of material within the stated limits ofsize. For example, the minimum shaft diameteror the maximum hole Stack-Up Analysis Example Limit dimension 20 22 MMC/LMC2222 LMC/MMC+ 20 202) 42 2) 2 21 1 Equal BilateralTolerance ( ) of part21 1 Tolerance Stack-Up Analysis Example Unequal bilateral Tolerance +1 50 3 MMC/LMC5151 LMC/MMC+ 47 472) 98 2) 4 49 2 Equal BilateralTolerance ( ) of part49 2 Tolerance Stack-Up Analysis Boundaries Virtual ConditionThe virtual condition of a feature specified at MMC is aconstant boundary generated by the collective effects ofthe MMC limit of size of a feature and the specifiedgeometric condition calculations:External Features (Pin)Internal Features (Hole)MMCMMCPlus Geo.

2 Tol. @ MMCM inus Geo. Tol. @ MMEqualsVirtual ConditionEqualsVirtual ConditionTolerance Stack-Up Analysis Resultant ConditionThe resultant condition of a feature specified at MMC isa variable boundary generated by the collective effectsof the LMC limit of size of a feature, the specifiedgeometric Tolerance , and any applicable bonus resultant condition calculations:External Features (Pin)Internal Features (Hole)LMCLMCM inusGeo. Tol. @ MMCPlusGeo. Tol. @ MMCM inusBonus TolerancePlusBonus ToleranceEqualsResult. ConditionEqualsResult. ConditionTolerance Stack-Up Analysis Tolerance Stack-Up Analysis Virtual and Resultant Conditions, HoleVC/RC5454RC/VC+ 48 482)102 2) 6 51 3 Equal BilateralTolerance ( ) of part51 3 Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis Virtual and Resultant Conditions, PinVC/RC4848RC/VC+ 42 422) 90 2) 6 45 3 Equal BilateralTolerance ( ) of part45 3 Tolerance Stack-Up Analysis Tolerance Stack-Up Analysis