A substrate transport apparatus (26B, 26i, 2080, 11013, 11014) comprising: a frame; and a drive section connected to the frame, the drive section including: a multi-drive shaft spindle, with at least one coaxial shaft spindle (450, 451), more than one different interchangeable motor module (401A, 401B, 401C) arranged in a stack, each having a motor (401M, 401M') operably coupled to a corresponding shaft (450, 451) of the multi-drive shaft spindle and defining a corresponding independent drive axis of the drive section, the motor (401M, 401M') of each motor module (401A, 401B, 401C) respectively having a motor stator (401S, 401S'), fixed to the frame, and a motor rotor (401R, 401R') joined to the corresponding coaxial shaft spindle (450, 451), and a can seal disposed between the motor stator (401S, 401S') and motor rotor (401R, 401R') of each motor module (401M, 401M') and hermetically sealing the respective motor stator (401S, 401S') and motor rotor (401R, 401R') from each other; wherein at least one of the different interchangeable motor modules (401A, 401B, 401C) in the stack is selectable for placement in the stack from other different interchangeable motor modules (401A, 401B, 401C) capable of placement in the stack, each having a different predetermined characteristic, independent of placement in the stack, the different predetermined characteristic of the motor module (401A, 401B, 401C) defining a different predetermined drive characteristic of the corresponding independent drive axis, independent of coaxial shaft spindle (450, 451) location, so that selection of the at least one of the different interchangeable motor modules (401A, 401B, 401C) determines the different predetermined drive characteristic of the corresponding independent drive axis different from another of the independent drive axis. a frame; and a drive section connected to the frame, the drive section including: a multi-drive shaft spindle, with at least one coaxial shaft spindle (450, 451), more than one different interchangeable motor module (401A, 401B, 401C) arranged in a stack, each having a motor (401M, 401M') operably coupled to a corresponding shaft (450, 451) of the multi-drive shaft spindle and defining a corresponding independent drive axis of the drive section, the motor (401M, 401M') of each motor module (401A, 401B, 401C) respectively having a motor stator (401S, 401S'), fixed to the frame, and a motor rotor (401R, 401R') joined to the corresponding coaxial shaft spindle (450, 451), and a can seal disposed between the motor stator (401S, 401S') and motor rotor (401R, 401R') of each motor module (401M, 401M') and hermetically sealing the respective motor stator (401S, 401S') and motor rotor (401R, 401R') from each other; a multi-drive shaft spindle, with at least one coaxial shaft spindle (450, 451), more than one different interchangeable motor module (401A, 401B, 401C) arranged in a stack, each having a motor (401M, 401M') operably coupled to a corresponding shaft (450, 451) of the multi-drive shaft spindle and defining a corresponding independent drive axis of the drive section, the motor (401M, 401M') of each motor module (401A, 401B, 401C) respectively having a motor stator (401S, 401S'), fixed to the frame, and a motor rotor (401R, 401R') joined to the corresponding coaxial shaft spindle (450, 451), and a can seal disposed between the motor stator (401S, 401S') and motor rotor (401R, 401R') of each motor module (401M, 401M') and hermetically sealing the respective motor stator (401S, 401S') and motor rotor (401R, 401R') from each other; wherein at least one of the different interchangeable motor modules (401A, 401B, 401C) in the stack is selectable for placement in the stack from other different interchangeable motor modules (401A, 401B, 401C) capable of placement in the stack, each having a different predetermined characteristic, independent of placement in the stack, the different predetermined characteristic of the motor module (401A, 401B, 401C) defining a different predetermined drive characteristic of the corresponding independent drive axis, independent of coaxial shaft spindle (450, 451) location, so that selection of the at least one of the different interchangeable motor modules (401A, 401B, 401C) determines the different predetermined drive characteristic of the corresponding independent drive axis different from another of the independent drive axis.