A Machining Allowance is necessary if the optimization optimisation result is manufactured with the Additive Manufacturing processes. After printing the part all functional surfaces are post processed and therefore enough material needs to be available. So the optimization optimisation actually needs to produce different outputs for different requirements of the model - once a norm geometry and once a printing geometry.The optimization
Picture Norm Geometry vs MA Geometry
The optimisation is carried out and calculated without taking the Machining Allowance into consideration. 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 needs to be added to all functional surfaces. The picture below shows an example of the GD-Bracket.
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