How to Choose an Electric Motor: Custom Built Electric Motors

Video Transcript

Hi, this is Janette and Joe with Groschopp and this is the eighth video in our series, “How to Choose an Electric Motor.” In this video we hope to ease any concerns you may have about what’s involved in customizing a motor to fit your application. The biggest advantage of customization is that you don’t have to take a standard off-the-shelf motor and then try to make it “fit” your application.

We offer two types of customizations here at Groschopp. The first is modifying a standard motor and the second is creating a custom “blank sheet” design.

Modifying a standard design is typically the simpler, faster and more cost-effective way to get a custom motor that is optimized for your application. This includes things like custom windings, modified output shafts, end bells, and mounting faces. Changes to motor housings and mountings, as well as adding accessories such as brakes, encoders and power cords, are all part of the modification process.

Essentially, motor modifications include changes made to a motor’s design that doesn’t alter the frame size. Using a standard frame size can save time and money that would otherwise be needed for tooling on a custom size. There are many options to tailor the performance and mechanical interface of a motor without investing in new frame sizes.

An experienced motor designer can tweak motor performance by changing the winding, altering some of the speed or torque points; and if we start talking about intermittent duty applications, we may even be able to increase output horsepower without making the motor any larger.

In comparison, a “blank sheet design,” it is typically created for someone needing a high volume of motors outside our standard frame size. Often, these customers already own the proper tooling or are in need of an extremely proprietary unit. In these instances, it makes the most sense to ‘start from scratch’ and design a completely custom motor. Although the initial investment can be significant, the lower cost of production motors leads to a relatively short payback time as you’re only paying for the motor you need.

Talk to an experienced motor designer and manufacturer for help determining if a modified or custom motor is the better option for you.

Before we wrap up, I’d like to introduce you to a great little formula that is a part of our toolbox to help determine which type of design should be pursued.

It’s the “D-Squared-L rule.” In general, a motor’s relative ability to supply a certain level of continuous output power is dependent on this “D-squared-L” rule. “D-squared-L” means that the diameter of the stator squared, is multiplied by the length of the stator, to give you a value that represents the relative output power of a motor. You can calculate this for the motors you’re considering and compare them.

So, if you need a motor with higher continuous output power, you will either need a larger diameter motor, a longer motor, or a different motor type that has a higher power density.

Keep watching, in the next video: “Case Studies,” we’ll give you real life examples of all we’ve talked about up until now. And for more information about Groschopp or any of our products, check out our website at www.groschopp.com.

How to use the Motor Search Tool

Narrow your search by selecting motor type, gearbox, voltage, and phase options for your desired motor.

Select a dominant variable: choose one of the three parameters to narrow your search. The selected variable determines which slider bar you will be able to manually move.

Use the slider corresponding to your dominant variable to further narrow your motor selection. The other sliders will automatically move to show available ranges based on the range of your selected variable.

Results will upload as your search criteria changes. If you have any questions regarding your results or how to use the search tool, you can chat with us using the green tab on the left-hand side of your screen.


Note: Groschopp Universal motors are custom built to fit your application so no additional options are available to narrow the search. Selecting the Universal motor type will prompt a message taking you to the Universal product page.

Not sure what you need?

One of our team members would be happy to help. Contact us at 800-829-4135 or by email at sales@groschopp.com. You can also chat with us using the green tab on the left side of your screen.

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Universal Motors

Groschopp Universal motors are custom built to fit your application so no additional options are available to narrow the search. Standard frame sizes and motor features can be found on the Universal page.

go to Universal page