we describe a method of manufacturing a housing for the stator of an axial flux permanent magnet machine , the machine having a stator comprising a set of coils wound on respective stator bars and disposed circumferentially at intervals about an axis of the machine , and a rotor bearing a set of permanent magnets and mounted for rotation about said axis , and wherein said rotor and stator are spaced apart along said axis to define a gap therebetween in which magnetic flux in the machine is generally in an axial direction , the method comprising : fabricating a radial wall for said stator housing to be located in said gap between said rotor and said stator by : placing a resin membrane into a mould of an injection moulding machine ; injection moulding a set of reinforcing features onto said membrane using a thermoplastic polymer bondable when molten with said resin ; and manufacturing said housing using said radial wall .