The actual results of the PCB effect (note slot edge) in the different layers of the hole shape are drawn in different layers of the slot shape (note the slot edge)
Many friends asked in the use of Altium designer PCB design, want to open a slot on the board or dig a hole how to operate, is the use of keep-out layer or mechanical layer, today, here to answer, both in the actual operation are used (and large people use), But neither of them is normative and there are hidden dangers. The correct approach is to use the "Board cut" (board cutout) method.
The specific method is to draw a hole in any layer of the shape, and then select the shape of all the lines, select Tools-->convert-->create Board cutout from Selected Primitives. This completes a true hole grooving operation, allowing you to see the effect in the 3D preview.
It is said that it is possible to draw a shape on any layer, and the actual situation is slightly different. If the keep-out layer is drawn, there will be no copper on the edge of the slot after the copper is covered. It is recommended to use the mechanical 1 layer to have copper on the edge of the slot. Please refer to the drawings for more experience.
How to open slots in Altium designer PCB