Shafted: A shafted encoder requires two special interfaces to properly mount the unit: the encoder mount and flexible coupling.
Hubshaft encoders are similar to the hollowshaft configurations except the shaft does not extend through the encoder.
Hollowshaft: The motor or machine shaft extends through the hollow encoder shaft and is affixed by a concentric clamp.
Bearingless: NEMA motors come with standard interface dimensions on the face for mounting aligning accessories.
Kit/Modular encoders offer a modular assembly, eliminating the bearings, similar to the frameless resolver.
Housed: This design eliminates the normal brushslop ring sliding contact used in conventional resolvers.
Frameless: Designed for standard resolver motor mounts, the resolver rotor mounts to the shaft and the resolver housing mounts to the motor face.