The cyclonic action of your nutribullet requires the use of liquids to make blasts and other nutritious beverages. It is not intended to be used as an ice crushes, and not without liquids.
If you want to make a great, cold NutriBlast, we suggest you use frozen fruit and chilled liquids. Alternatively, you may add crushed ice, up to 25% of the total cup volume, with water or other liquid filled up to the "MAX--" line. Do not crush ice or other hard items without liquid, as such prolonged use may dull or damage your blades. Always inspect your blades before each use.