The pilot was familiarizing himself with the home built helicopter. After hovering in one general area for about 45 minutes, he decided to hover to an open area by crossing a fence. He stated that he entered translational lift at about 20 knots while hovering forward. At this time, the helicopter began rolling to the left. Full right cyclic failed to correct the roll. The helicopter continued to roll left and struck the ground with the main rotor blade and left skid. For solo flight, the ship's battery must be repositioned in the nose, and lead weights must be attached to the right skid for proper weight and balance control. The pilot stated that he had made those alterations prior to flight. An on-site investigation indicated that the battery and lead weights were thrown free of the helicopter. Insufficient data was available to ascertain the aircraft's center-of-gravity at the time of the accident. The flight controls had retained their continuity. The elevation was about 3700 ft.