An apparatus comprising: a shaft, an actuator controlling translation of the shaft, and a pneumatic shaft positioning system (100; 200) comprising: a first pressure chamber (109; 141) and a second pressure chamber; a pressurized gas source (135; 405) coupled to the first pressure chamber and connected to the second pressure chamber; a first valve (137; 407) controlling flow of gas from the pressurized gas source into the first pressure chamber and into the second pressure chamber; and a first piston (113, 115; 143) protruding into the first pressure chamber (109; 141) and slidably coupled to the first pressure chamber, wherein the first piston contacts said shaft and forces said shaft in a first direction into a predetermined position when the gas from the pressurized gas source (135; 405) fills the first pressure chamber (109; 141), a second piston (117, 119) protruding into the second pressure chamber and is slidably coupled to the second pressure chamber, and wherein the second piston (117, 119) contacts the shaft and forces the shaft in a second direction into the predetermined position when the gas from the pressurized gas source fills the second pressure chamber, such that the first direction is opposite to the second direction, characterised in that the first pressure chamber and the second pressure chamber are separated by a second valve preventing flow of the gas from the second pressure chamber to the first pressure chamber, and wherein the first pressure chamber comprises a release valve configured to reduce a pressure in the first pressure chamber relative to the second pressure chamber. a shaft, an actuator controlling translation of the shaft, and a pneumatic shaft positioning system (100; 200) comprising: a first pressure chamber (109; 141) and a second pressure chamber; a pressurized gas source (135; 405) coupled to the first pressure chamber and connected to the second pressure chamber; a first valve (137; 407) controlling flow of gas from the pressurized gas source into the first pressure chamber and into the second pressure chamber; and a first piston (113, 115; 143) protruding into the first pressure chamber (109; 141) and slidably coupled to the first pressure chamber, wherein the first piston contacts said shaft and forces said shaft in a first direction into a predetermined position when the gas from the pressurized gas source (135; 405) fills the first pressure chamber (109; 141), a second piston (117, 119) protruding into the second pressure chamber and is slidably coupled to the second pressure chamber, and wherein the second piston (117, 119) contacts the shaft and forces the shaft in a second direction into the predetermined position when the gas from the pressurized gas source fills the second pressure chamber, such that the first direction is opposite to the second direction, characterised in that the first pressure chamber and the second pressure chamber are separated by a second valve preventing flow of the gas from the second pressure chamber to the first pressure chamber, and wherein the first pressure chamber comprises a release valve configured to reduce a pressure in the first pressure chamber relative to the second pressure chamber. a first pressure chamber (109; 141) and a second pressure chamber; a pressurized gas source (135; 405) coupled to the first pressure chamber and connected to the second pressure chamber; a first valve (137; 407) controlling flow of gas from the pressurized gas source into the first pressure chamber and into the second pressure chamber; and a first piston (113, 115; 143) protruding into the first pressure chamber (109; 141) and slidably coupled to the first pressure chamber, wherein the first piston contacts said shaft and forces said shaft in a first direction into a predetermined position when the gas from the pressurized gas source (135; 405) fills the first pressure chamber (109; 141), a second piston (117, 119) protruding into the second pressure chamber and is slidably coupled to the second pressure chamber, and wherein the second piston (117, 119) contacts the shaft and forces the shaft in a second direction into the predetermined position when the gas from the pressurized gas source fills the second pressure chamber, such that the first direction is opposite to the second direction, characterised in that the first pressure chamber and the second pressure chamber are separated by a second valve preventing flow of the gas from the second pressure chamber to the first pressure chamber, and wherein the first pressure chamber comprises a release valve configured to reduce a pressure in the first pressure chamber relative to the second pressure chamber.