Rotary Servo – Do You Have the Right One for the Job?

Do you have the right Rotary Servo for the job you have to do? Prime Drives manufactures Rotary Servos and will work closely with you to ensure you have the right Rotary Servo for your application needs. Before deciding if you have the right one, however, it is important to understand what a Rotary Servo is, what applications they might be used for, and what benefits you can receive from using Prime Drives’ Rotary Servos.

What is a Rotary Servo? Also called a Direct Drive Servo, a Rotary Servo is a precision rotary positioning device. It is most often used in robotics, for antenna pedestals, and in medical patient beds. Rotary Servos are also used in machines which automate the placement of integrated circuits, capacitors, resistors and diodes. These are then placed on printed circuit boards and will become computer motherboards as well as the brains behind today’s top smart TVs or your iPad.

What applications use them? Rotary Servos are used in the following applications:

  • Automated pick and place machines
  • Machine tools
  • Robotics
  • Visual inspection machines
  • Medical patient beds for oncology detection and treatment
  • Entertainment/film industry for cameras
  • Military applications would include gun turrets on helicopters and tanks as well as cameras on unmanned aerial vehicles (UAVs)

Why would someone choose one type of Rotary Servo over another? Basically, Rotary Servo is a general term. It can be applied to any of the following: Direct Drive Servo, Parts Sets Servo, or simply a basic rotary table driven by a servo motor. The type of applications for which the Rotary Servo is needed will determine the type the engineers select.

How are the Rotary Servos from Prime Drives different from the competitors? What are the benefits of using them?

  • We have designed our Rotary Servos to be flexible offering more gear ratios and diameters than others available in today’s marketplace. This is what distinguishes ours from our competitors.
  • We design our Rotary Servos with four distinct diameter tables. These range from 4 inch diameter to 12 inch diameter. There are 24 various ratios within each of these diameter series.
  • We offer customization of the table. This can include a machined top plate which eliminates the need for an adapter plate. We can also add custom home sensors. Customization can also be made for the thru hole. This customization alleviates cable management issues or allows for laser pass thru capability.

When you’re ready to purchase a Rotary Servo for your application, contact us at 775-333-5984 or email us at

Achieving Accuracy with Direct Drive Rotary Stages

Achieving Accuracy with Direct Drive Rotary StagesDoes your application require an unusual level of precision? Does your current Direct Drive Rotary Stage meet your current torque requirements? If your answers to these questions was “no,” Prime Drives can design and manufacture Direct Drive Rotary Stages to meet your specific positioning needs.

Direct drive rotary stages can be designed with apertures of nearly any diameter and load capacity. Your application will determine the aperture size and load requirements.

Possible applications might include rotary testing, optical calibration, inertial navigation, electro-optic sensors (single or multi-axis), or antennas. Many fields require precise angular positioning including various electronic assemblies, medical, pharmaceutical, robotics, fiber optics, research institutions, microelectronics, photonics and defense and security.

How does a direct drive rotary stage help with accuracy?

  • Reduce or eliminate backlash
  • Better positioning accuracy
  • Increased speeds
  • Maximize performance related to tilt error
  • Reduce rotating friction
  • Eliminate wear problems connected with belt drives, worm-drive and gear-drive rotary stages
  • Reduced travel
  • Increased repeatability

An added benefit of this type of rotary stage is that it lasts longer and requires less maintenance than other rotary stage types. If space limitations are a factor, Prime Drives is able to design a Direct Drive Rotary Stage to fit within those constraints with a low profile, high precision design. with heights as small as 40 mm.

Aperture size needs may vary depending upon your application. Some factors to consider are the number of wires or vacuum lines routing through the aperture. We can design Direct Drive Rotary Stages with aperture sizes ranging from 10 to 300 mm. For more specification details refer to our product brochure or call our office at 775-333-5984.

Depending upon your specific requirements, often dictated by your industry, our team of experts can design the best possible solution for your company and your application. Whether your Direct Drive Rotary Stage needs are simple or very complex, our engineers will work closely with you to design equipment that will meet those needs.

The Advantages of Using Direct Drive Motors

Advantages of Using Direct Drive Motors graphicDirect Drive motors can be found in nearly every industry in one form or another. While some applications may require belts, chains or gearboxes to enable a product or machine to work properly, there are many benefits of using direct drive motors. Prime Drives manufactures direct drive motors that can be customized to suit your needs. What are the advantages of using direct drive motors over belted (or indirect) drives?

One of the main advantages of using direct drive motors is increased accuracy. Rather than dealing with a coupling, gearbox, belts or chains, a direct drive motor attached directly to the load thus there is not hysteresis in any direction of movement.

A direct drive motor also offers higher resolution feedback devices which allows you to attain the absolute accuracy required in precision applications.  Encoders can be configured to provide from 11,000 counts/rev to more than 4,000,000 counts per rev; all customized to fit the need of your application.  This allows our Direct Drive motors to achieve +/- 3 arc-seconds of absolute accuracy in extremely demanding applications.

Along with having fewer parts that could create noise and vibration, a direct drive motor will provide a unique packaging option not found in typical servo motors.  Prime Drives Direct Drive Motors can be packaged to provide a large thru hole in the middle of the motor which can be used for cable management, laser positioning pass thru or pneumatic hose management.  Direct drive motors can also be designed to have a large diameter and short height in a ‘pancake’ style or we can offer a taller configuration with a smaller diameter for applications which are restricted in larger diameter package configurations.

Direct drive motors can also provide higher torque at lower revolutions per minute (rpm). Some applications require a higher torque but need this at a lower speed. Prime Drive’s Direct Drive Motors are customizable so they can provide the needed torque at lower rpm speeds. The torque-to-inertia ratio is also higher in direct drive motors, specifically where it is needed most – at the load. Because there is a low electrical time constant for torque motors, the torque can develop quickly when voltage is provided. This quick response aid servo stiffness and angular positions.

Elimination of torque ripple is another advantage of the direct drive motor as we can offer non-cogging rotor-stator sets which provide large pole counts and are staggered to eliminate cogging normally found in competitors direct drive models. When your application requires the absolute elimination of any torque ripple, our slotless designs can provide your application a solution.

If these advantages are what you need for your application, give us a call at (775) 333-5984. We’ll discuss your needs and determine how we can help meet them with a customized direct drive motor.

Applications Where Direct Drive Motors Are Used

Applications Where Direct Drive Motors are Used GraphicDirect Drive Servo Motors are used in a wide range of today’s automation tasks. Since automation is employed in a number of industries, you might wonder which applications the Direct Drive Servo Motor is used most often.

Direct Drive Servo Motors are small and compact. They can be customized to match the speed, inertia, torque and accuracy requirements for your application. How do you know if a Direct Drive Servo Motor is right for your particular job?

Consider the needs of the automotive industry. Automotive manufacturing facilities use a variety of robotic units. These robots can duplicate specific, controlled motions repeatedly for the life of the robot. The movements are dictated by the Direct Drive Servo Motors within the robot and they control the speed of the movements, torque, accuracy and repeatability. You may find robots being used for paint booths, machining centers, assembly conveyors, welding robots and punch presses. If your industry uses robots to manufacture your products, Prime Drive’s Direct Drive Servo Motors may be the right choice for your application. Both brushed and brushless motors will be used in industrial robots.

Solar manufacturing companies also use Direct Drive Servo Motors. These motors, however, will be required to perform minute movements for etching the surface of the wafers for solar cells. Direct Drive Servo Motors will also be used for custom robotics solutions and to control movements of the solar panels once they are installed.

Does your application require accuracy and repeatability? Our Direct Drive Servo Motors are also used in medical equipment, inspection equipment, food packaging, prescription drug packaging equipment and the film industry. You can also find these motors in use in the homeland security and grinding industry along with semiconductor equipment, aviation automation and metrology equipment.  +/- 3 arc-sec absolute accuracy is achievable.

It is important that we understand your needs as a new client. Our engineers will meet with you to learn what configuration is needed and initiate the design process. We’ll need to know what speed is needed for the motor including the top speed and low speed. How much torque will be required for the motor? What is the absolute accuracy needed? Will package size constraints including maximum diameter or maximum length be a concern? Our engineers will work with you to design a motor around the space your application has available.

Other features you may need to consider for your application are feedback options, custom winding, environmental concerns (whether the motor will operate outdoors), move profile needed and load. When your application requires direct drive servo motors, call Prime Drives. We’ll work with you to deliver the solution your application requires.