Motors support several different feedback devices including optical absolute encoders, sine encoders, resolvers, and optical commutation encoders. A smart feedback device, the SFD, contains motor identification and automatically sets up the drive for specific motor characteristics. One end-bell is used for several different motors, simplifying assembly and augmenting motor quality.

There are more than 75 industry-standard motor mounts currently in use worldwide. Two of the more common ones come from the National Electrical Manufacturers Association (NEMA) and the International Electrotechnical Commission (IEC). Manufacturers typically make motors with a common set of castings that fit a wide variety of standards such as the Japanese metric, European metric, and North American NEMA standards.

For example, the casting for the basic 58-mm AKM motor from Danaher also fits the Japanese 60-mm standard and the North American NEMA-23 standard. The required mounting-hole drill modifications take place during machining before final assembly. One casting, one process, and one procedure now make 75 different motor mounts among seven different motor sizes. This method simplifies quality control and manufacturing processes. The large variety of mountings adapt easily to different mechanical components or machine configurations.

A flange mount is the most common form used with gear-boxes. Flange-mount motors, like many motors that mount directly to machinery, have a raised circular surface on their face concentric with the output shaft. This is called the pilot. A pilot recess is machined in the mounting surface of the machine or mechanism. The pilot and pilot recess guarantee that motor and machine shafts align accurately.

Occasionally an output shaft needs modification to mate with another manufacturer's mechanism or specific load. It might require a special keyway, different diameter or length, a spline, or a taper. The factory should make these modifications to ensure the machining is accurate.

A commutating encoder provides output signals with resolutions from 1,000 to 5,000 lines/rev. The outputs for the Danaher AKM series can sink or source 40 mA max with a frequency response of 300 kHz at a maximum speed of 12,000 rpm.

Any reductions in shaft diameter should get scrutiny from engineering. Small diameter shafts can fail prematurely when subjected to peak torques. In addition, reducing shaft diameter also reduces shaft torsional resonant frequency (TRF). Lower TRF can degrade overall system response. Designers may have to reduce drive gain to prevent exciting resonances that can produce excessive vibrations. Similarly, longer shafts require engineering evaluation with regard to bending limits and bearing loads.

Seals protect servomotors against solids or liquids that can enter and hamper performance or life. Seals guard the motor body and electrical connections as well as the output shaft. Motors exposed to liquids should use seal materials that do not deteriorate in their presence.

Motor seals reverse their function in clean-room environments like those in semiconductor manufacturing. They protect the environment from possible contaminants the motor emits. Brushless motors have an inherent advantage over brushed servomotors in clean environments. They don't produce carbon dust from brush wear.

A brake holds an axis of motion in position without servocontrol. The most common application is a vertical axis driven with a ball screw or other mechanism that can fall when the servo is not energized. But brakes can provide static parking and emergency braking on any axis. They are considered fail-safe, meaning they mechanically engage when they are electrically off. So power failures automatically engage the braking system.

Unlike automotive disc brakes, fail-safe brakes are not intended for repetitive operation in a dynamic mode. They do not have the surface area to endure nor the heat sinking ability to dissipate a lot of energy continuously. An application needing a dynamic brake for more than an emergency should have an external brake designed for that purpose.

The most common types of feedback devices used for servo-motors are resolvers, incremental encoders, and sine encoders. They come in wide ranges of accuracy, resolution, and repeatability.