Preferences - Fixtures Tab
Max Top Thickness: The maximum thickness of the top surface.
Min Top Thickness: The minimum thickness of the top surface. The lower this value is, the better the fixture will cradle the part.
Wall Thickness: Sets the thickness of the Fixture wall.
Distance between walls by X: The distance between the Fixture walls in the X direction.
Distance between walls by Y: The distance between the Fixture walls in the Y direction.
Base Grid Thickness: Determines how high the part is moved from the bottom of the build box to accommodate the fixture base.
Accuracy coefficient: Set the value for separating the part and the fixture for parts that have vertical, or nearly vertical, walls. The smaller the degree of separation, the better the fixture will follow the shape of the part. Run Collision Detection to see if the fixture is touching the part. If it is, increase the Accuracy Coefficient by a small amount and rerun Collision Detection.