Only straight slots can be recognized. They are recognized from straight, parallel side surfaces. You must select surfaces on both sides of the slot. In the example below, the shaded surfaces are the selected surfaces. The extent of the slot is defined by these surfaces. Note that the flat bottom surface is ignored.
For interrupted slots, select surfaces on each end. In the picture below, the slot is interrupted, but can be created by selecting the wall surfaces at either end.
If the feature you are trying to recognize is a straight cut that extends off the side of the part, as in the yellow region of the part shown below , use a side feature. You cannot recognize such a feature as a slot, since there are not two opposing side walls.
Note that chamfers, draft angles and bottom radii cannot be recognized, but you can add these parameters to the slot in the Dimensions page of the New Feature wizard. See Slot feature for more general information on slots. See How to recognize features from surfaces for a description of the overall process. See Feature recognition surface requirements for further information on how surfaces are used in feature recognition.