Types of burr-drills:
Steel burrs with very deep grooves, these are the roughest ones. They are suggested to apply on very funguous nails.
Rakers: these are less deeply grooved (are grooved longitudinally), can be used for polishing rough nails and are suitable for removing yellowness, too.
Polishers: polishers with diamond powder. There is no rule for what kind of polisher should be used as it always depends on the foot of the guest.
It is not allowed to store the machine without the burr-drill!
IT IS FORBIDDEN to take it apart in case of a fault! (Leave it to a specialist!!!)