When to Use DMP Flatness

In this Question Line video, Brandon answers the following question regarding the use of Flatness for a width feature of size: 

My colleagues and I are having a dispute about Flatness applied to a width dimension. Some are saying that I need to add Flatness to the surfaces because when applied to the dimension the surfaces are uncontrolled. Is this true? If so, when should I apply Flatness to the dimension instead of the surface?

Brandon explains the application of derived median plane (DMP) Flatness and discusses its frequent misuse and potential issues when used for stacking parts. He also provides an alternative for controlling flatness for stacking or symmetrical parts. 

For more information regarding Flatness, check out this article: Flatness – Surface vs. Feature of Size.

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