Abstract: A rotary atomiser drive spindle for use as part of a rotary atomiser, the drive spindle comprising a shaft which carries a turbine and a body which comprises at least one supply channel for supplying gas to the turbine for rotatingly driving the shaft relative to the body. The turbine comprises a rotor body portion, which is ring shaped, and a plurality of blades projecting from one of the generally flat surfaces of the rotor body portion. Generally radial gas paths through the turbine are defined by adjacent pairs of blades. The at least one supply channel comprises a nozzle portion from which, in use, gas leaves the body of the spindle towards the turbine. Each nozzle comprises an outlet and the cross sectional area of the gas passage through the nozzle portion decreases monotonically from the inlet of the nozzle to the outlet. Two turbines may be provided and exhaust air may be used for cooling.