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Archive: Mar 2022

Slotted vs. Slotless Brushless Motors

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Slotless motors were first designed when manufacturers needed to create an improved brushless motor design built for low-power applications. Today’s slotless stators present unique advantages such as smooth performance and less cogging. Cogging, which occurs when the rotor and stator slots align and make the motor unable to start, is a common problem with motors at less than 500 rpm. It is also one of the most common reasons why people switch from slotted to slotless brushless motors.

Learn more about the different constructions of these two motor types, the advantages and common applications of each type, and the value of choosing Elinco as your supplier.

Construction of Slotted vs. Slotless Brushless Motors

Slotted and slotless brushless motors have several key differences in their construction that impact performance and longevity.

Slotted Motors

Brushless motors have a rotating, magnetic rotor with fixed windings arranged around the exterior of the rotor. In a slotted motor, the central stator core is built of laminated steel with slots and teeth. The copper wire winds between the teeth in the slots. When the teeth are longer – or closer to the central magnet – the motor has increased torque.

Slotless Motors

Slotless motors are also brushless motors with a rotating, magnetic rotor. However, the steel lamination is smooth and doesn’t have teeth (or slots) for copper wire to wind around. Instead, manufacturers wind the copper coils in a unique cylindrical shape. This configuration gives slotless motors their signature smooth performance, with low noise levels and little to no vibration, while providing high levels of power.

Performance Differences and Applications for Slotted vs. Slotless DC Motors

Because of the different winding configurations, slotted and slotless motors each provide different advantages. Slotted motors, for example, outperform slotless varieties when it comes to generating high levels of constant torque and being able to accelerate quickly. Slotless brushless motors, on the other hand, excel at smooth motion with little to no velocity ripple and having good tour constant (Kt) linearity. These motors also have the largest through holes.

These differences in performance mean they each work best for different applications and industries. 

Parameter Slotted Slotless
Smoothest Motion (Lowest Velocity Ripple)

Highest Torque Constant

Torque Constant (Kt) Linearity

Largest Through Hole

Highest Acceleration Rates

Slotted Motors

Slotted motors work best in applications where compact size isn’t an issue and the machinery needs multiple poles. They can also perform in a variety of adverse conditions and environments, because manufacturers can better protect the windings from future debris or likely damage. This means they’re commonly used in appliances, electric vehicles, and other large electrical machines.

SL Series SlotlessSlotless Motors

Slotless motors work best in small precision tools. Not only do these motors have a compact size, but their smooth torque and movement are much less likely to interfere with performance. Manufacturers often pair slotless motors with medical devices and handheld tools.

Elinco DC Motors

Elinco JPC is a leading designer and manufacturer of slotted and slotless brushless motors. Innovation and long-lasting relationships built on product quality are core tenets of our business. We serve the industrial, office, medical, and military marketing sectors with consistently reliable products that are built to be cost-effective and meet our clients’ quality standards across all fields. 

Our in-house engineering team is focused on developing new solutions and designs for both our slotted and slotless brushless DC motors. We provide assemblies capable of generating power levels from 400W to 8,000W and beyond. Our Elinco slotless SBLDC product line motors can be used in everything from high-torque surgical tools to medium-power medical pumps to fully autonomous vehicles based on our clients’ performance requirements and design considerations.

Order Your Slotted or Slotless Motor From Elinco International JPC

Slotted brushless motors are powerful, rugged assemblies for powering large machinery, while slotless brushless motors are capable of powering fine-tuned control for a wide variety of handheld tools. Our team at Elinco designs and builds DC motors of both classifications to power our clients’ systems and devices. Contact us today to learn more about our products or to place your order.