The pilot had built the single seat aircraft himself and had previously only flown it on one occasion. After completing the first circuit, the aircraft was taxied back to the threshold and the second take-off commenced. Just after lift-off the aircraft was observed to pitch nose up. The right wing dropped and the aircraft turned to the right before impacting the ground. When the aircraft tail came up during the take-off roll, the pilot became concerned that it was too high and that the propeller might strike the ground. In attempting to avoid this, excessive back pressure was applied to the control column. The aircraft became airborne prematurely and then stalled.