What do you mean by "slanted?" Anyway, as long as the opening of the hinge slot is centered in the TE of the wing and the LE of the aileron I don't think it matters if the slot is "slanted." (I assume, by slanted you mean the slot angles upward or downward if viewed from a cross-section.)

Or, as long as the aileron aligns with the wing, you'll be fine (providing there is enough "meat" around the hinge to hold it securely).