Software simplifies servo motor and drive sizing for new machines

Oct. 3, 2019
Design engineers have long struggled with manual calculations and spreadsheets to properly size servo motors and drives for new machines. A recently launched update of Mitsubishi Electric’s Motorizer software simplifies the process, promising to reduce the time and headaches involved in sizing these components in a wide range of applications.

“Motorizer serves as a virtual test chamber, allowing engineers to consider different design approaches and compare the results in seconds. It selects from among Mitsubishi Electric’s extensive catalog of AC servos and inverters,” says Dan Zachacki, senior product marketing engineer.

“When designing complex machines with multiple interconnected or synchronized axes, the math for calculating torque and speed requirements can be very complicated,” he explains. “If you make a change to a single component, it can affect every calculation in your design. If your calculations are wrong your design might not work as expected or you could experience a premature failure. The software assists you with these design calculations automatically, enabling you to quickly identify the motor and drive that best fits the application.”

Applications covered in the Motorizer software include ball screw, rack and pinion, roll feed, rotary table, cart, elevator/hoist, conveyor, fan, pump, generic rotary, generic linear, and linear servo.

Key to making the most out of the software is to enter the correct machine values into the program. Among these factors are physical dimensions, operation pattern, load, inertia, friction, and the motion profile. “If you know the machine side, Motorizer helps you with the motor side,” adds Zachacki.

The software allows you to combine up to 30 elements in a motion profile, or you can import an existing motion profile from third party software. Design a single axis or select components for multiple axes while you explore different motor and amplifier combinations.

“Once you make a selection, a table in the software results window indicates whether these values are the right fit for the application,” he says. “By comparing utilization of the product and using an easy-to-understand color coding system, you can easily select the right product for your requirements.”

The results list shows multiple solutions at once, including motor and drive models, drive capacities, and calculated results of effective load ratio and moment of inertia.

“The usefulness of the software,” says Zachacki, “is not only that it can save you time in the design stage, but it allows you to consider mechanical alternatives and test out your ideas without first having to purchase a component. In addition to testing your work, you can also save and share sizing data with partners or application engineers, or print it out for future reference.”

More accurate sizing calculations based on a better assessment of machine values might also limit the widespread practice of over-sizing, which contributes to higher initial machine costs and excess energy usage for customers over time.

“It’s common for engineers to upsize motors to account for ‘worst-case’ scenarios,” says Zachacki. “This takes away from the bottom line of the machine builder. The key to improving performance and reliability while reducing cost is a properly-sized servo system. If you take sizing seriously, you can use it as a framework for evaluating your machine design and performance through all your design iterations.”

The Motorizer software can be downloaded for free from Mitsubishi Electric’s web site, at this link.