The maximum size of a routing is determined by various factors, e.g. motor power of the drive unit, diameter of the tool, length of the tool shank, stroke height of the router. Under no circumstances should you attempt to cut such routing in one pass. This can lead to overloading of the motor and overheating of the tool cutting edges (causing them to dull). In the worst case, it can also lead to loss of control of the hand router or to the workpiece kicking back. You should always route large and deep routs in several passes, removing only a small amount of material at a time.