A method of making a rotor yoke includes preparing a cured composite rotor yoke preform on a single-sided curing tool and machining at least one portion of the cured rotor yoke preform to form a rotor yoke. In one embodiment, preparing the cured composite rotor yoke is accomplished by applying successive layers of uncured polymeric composite material to a single-sided tool in a configuration to produce an uncured rotor yoke preform; disposing a semi-rigid caul to an untooled side of the uncured rotor yoke preform; enclosing the uncured rotor yoke preform and the semi-rigid caul by substantially hermetically sealing a vacuum bag to the tool; substantially evacuating a volume defined by the vacuum bag and the tool of air; and heating the uncured rotor yoke preform, sometimes under pressure, to form the cured composite rotor yoke preform.