Abstract: A blast cleaning machine for impacting workpieces with high speed abrasive particles includes a conveyor in the form of a generally horizontally oriented cylindrical cage. The cage has a hollow center within which workpieces are disposed and a wall in the form of a helix. The inner diameter of the cage and the pitch of the helix are such that the cage supports, rotates, and translates the workpieces. A rod can be secured to the inner surface of the wall in order to assist in rotating the workpieces as they move through the cage. In the preferred embodiment, the ratio of the inner diameter of the cage to the pitch of the helix is approximately 2.2:1.