This disclosure describes methods and systems for remote control of stroke length and frequency of percussion apparatus, such as a rock hammer drill. At a high level, the hammer drill is allowed to stay at a default low stroke length and high frequency to avoid applying excessive cyclic stress to the housing of the hammer drill and can be controlled to operate at a long stroke length and low frequency when the hammer drill has engaged the target material. The long stroke length and low frequency during operation can be initiated when a sufficient forward feed pressure is provided. While the hammer drill is idling or retracting, the forward fee pressure is not sufficient for the long stroke length operation and thus the drill operates at the default state and at a safe stress level to avoid premature damage.