The accuracy of the CAD model that is imported into EdgeCAM
is a crucial element in defining the accuracy to which the model can be
machined. To ensure that the model is machined to the required accuracy
in EdgeCAM you should ensure that the model is created in the CAD system
to at least the desired machining tolerance.
Also see the notes in Loading of Granite Models (Solid Machinist for Granite licence only)
Please refer to the documentation of your CAD system on how to check and/or configure the accuracy of the model to be exported.