A Machining Allowance is necessary if
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the optimization result is manufactured with the Additive Manufacturing processes. After printing the part all functional surfaces are post processed
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and therefore enough material needs to be available. So the optimization actually needs to produce different outputs for different requirements of a norm geometry and a printing geometry.
The optimization is carried out and calculated without taking the Machining Allowance into consideration
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So the MA is put on top of the design after the optimization step has taken place.
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Scheme how the material is distributed with MA
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. It is added after the calculation process is done but before any smoothing algorithm has run over the geometry to guarantee a design without any transition problems between these different geometries.
The Machining Allowance need to be added to all functional surfaces. The picture below shows an example of the GD-Bracket.
GD Bracket Model Browser with MA
Touching faces should always be selected in one Machining Allowance because only then the Machining Allowance is one connected volume instead of just several offsets of the faces. The picture below shows the difference of the selections:
One MA vs. several for connecting faces.