Kollmorgen servo motors are now available with our fourth-generation SFD-M smart feedback device. Offered at no additional cost over Kollmorgen’s earlier SFD models, this encoder offers four times greater positioning accuracy and uses energy-harvesting technology to track absolute multi-turn positioning even when the system is powered off.
RADFORD, VA., 03/25/2025 — Kollmorgen, a global leader in motion control and automation systems, today introduced the new SFD-M (Smart Feedback Device, Multi-Turn). It allows machine builders to achieve high-resolution multi-turn feedback with absolute positioning information available at system startup.
Designed to work with AKD™ and AKD2G drives, the SFD-M absolute multi-turn encoder can be integrated into Kollmorgen housed servo motors at no additional charge compared to the SFD-3 single-turn absolute encoder, providing multi-turn performance, four times greater positioning accuracy and fifty times lower EMF noise.
Comparable third-party encoders come with a premium price. With the SFD-M, customers can achieve substantial savings in machine designs that perform at the highest levels of precision, efficiency and effectiveness.
Absolute multi-turn positioning for precise, productive motion
The SFD-M measures the position of the rotor shaft throughout each 360º rotation without requiring reference to a home position, and it registers the total number of rotations the shaft has made in either direction.
This absolute multi-turn positioning capability is ideal when precise tracking of position is required over large rotational distances, such as in machine tool positioning, packaging machines, material handling, satellite tracking and many other applications.
Additionally, the SFD-M maintains absolute positioning information in real time even when the system is powered down, eliminating the need for time-consuming homing sequences upon startup.
Energy-harvesting technology for battery-free operation
Absolute multi-turn encoders from other providers often require a battery to retain positioning information when the system is powered down or during a power failure. These external batteries require replacement and can be subject to failure. Other alternatives use mechanical gear trains, which are noisy, backlash-prone and add size to the motor.
The new Kollmorgen SFD-M eliminates these issues, instead using energy-harvesting technology to reliably maintain positioning information with no need for batteries or gear trains. Battery-free operation eliminates maintenance issues while also supporting efforts to reduce the consumption of natural resources and minimize waste.
Exceptional performance at an exceptional value
The SFD-M is highly accurate, offering these key specifications:
- Resolution
- 24 bits per revolution
- 16,777,216 counts per revolution
- 0.0772 arc-sec per count
- Multi-turn absolute range
- 16 bits = 65,536 motor revolutions
- Accuracy
- < +/– 1 arc-min typical at 25ºC
- < +/– 3 arc-min worst case
“Our new SFD-M encoder provides multi-turn absolute functionality with exceptional position accuracy and resolution at zero additional cost over Kollmorgen motors with single-turn encoders,” said Chris Cooper, Kollmorgen’s Senior Director of Global Product Management.
“That’s a huge benefit for precision and productivity at a savings of hundreds of dollars per motor and potentially several thousand dollars in a complex, multi-axis machine. Single motor-to-drive cable technology with auto drive setup further lowers total costs. We are very proud to offer all of these benefits to our customers as an integral part of Kollmorgen’s industry-leading servo systems.”
About Kollmorgen
Kollmorgen, a Regal Rexnord™ brand, has more than 100 years of motion experience, proven in the industry’s highest-performing, most reliable motors, drives, AGV control solutions and automation control platforms. We deliver breakthrough solutions that combine exceptional performance, reliability and ease of use, giving machine builders an irrefutable marketplace advantage.
Specifications are subject to change without notice. It is the responsibility of the product user to determine the suitability of this product for a specific application. AKD is a trademark of Kollmorgen Corporation. Regal Rexnord is a trademark of Regal Rexnord Corporation.
