To properly specify a direct drive hollow shaft motor, the design engineer needs to: define the move profile that is desired, distance, move time, settling time, duty cycle and the inertia of anything the motor is moving. For continuous moves at a constant velocity like a laser system, the demands on the motor are typically easier unless this happens to be running in a vacuum where the scanner is on a satellite designed to map the surface of a planet. High repetition rate positional moves are sensitive to inertia matching and types of coupling, in addition to harmonic vibrations in the mounting structures.
Specific industrial automation processes where the production machine benefits from a hollow motor include: cable winding, coax cable wrapping, fiber optic depositions, optical systems (where rotating the optic with the beam on centerline is advantageous), custom linear actuators and space-constrained applications where coaxial mountings make a smaller package. Additionally, Empire Magnetics provides hollow-shafted motors for extreme and challenging environments including: vacuum/space, waterproof/deep sea, radiation resistant and others.