Rexroth KSM01.2B-061C-35N-M1-HP2-SE-NN-D7-NN-FW | IndraDrive M Direct Replacement 1-Year Warranty

Description

Key Technical Specifications

• Rated Speed: 3500 RPM (Max speed often 4000-4500 RPM depending on drive config)
• Rated Torque: 6.1 Nm (Continuous)
• Peak Torque: ~18.3 Nm (3x overload capability for short durations)
• Voltage Rating: 400–480 V AC (DC Link)
• Encoder Type: Absolute Multi-turn (Resolution: 20-bit+), Interface: EnDat 2.2 or Hiperface (Check suffix D7)
• Connector Type: M23 (Power), M17 or M23 (Feedback/Encoder) – Verify physical keying
• Protection Class: IP65 (Shaft seal included), IP20 (Connector area without mating plug)
• Insulation Class: F (155°C)
• Brake Option: No holding brake (Suffix indicates “NN” for no brake usually, verify specific build)
• Flange Size: IEC 112 mm (Approximate, matches KSM01 frame)
• Shaft Diameter: 24 mm (Keyed or Smooth? Suffix 35N usually implies smooth with keyway, verify drawing)
• Thermal Sensor: KTY84-130 or PTC (Integrated in winding)

Product Introduction

You don’t find these KSM01 motors sitting on a shelf anymore. When they were new, they were the workhorses of high-speed cartoning machines and robotic pick-and-place cells. I’ve pulled these out of machines that ran 24/7 for a decade, covered in cardboard dust and glue spray, and the windings were still pristine. The “35N” in the model number tells you it’s built for speed—3500 RPM is nothing to sneeze at when you’re indexing a conveyor every 200 milliseconds. The real kicker is the encoder system. If the suffix says “D7”, you’re dealing with a high-resolution absolute encoder that remembers position even after a power cut. That saves you hours of homing routines every morning.But let’s be real: buying this today means you’re likely fixing an old machine because the budget for a full line upgrade got cut. Again. These motors pair specifically with older IndraDrive M or HCS02/03 drives. They aren’t plug-and-play with the newest IoT-ready drives without some parameter massaging. The build quality is typical German engineering—heavy, over-spec’d, and annoying to lift into tight cabinets. But once you bolt it down and tune the current loop, it holds position tighter than a vice. Just make sure your drive firmware knows how to talk to that specific encoder type, or you’ll get a “Encoder Fault” alarm before the shaft even turns.

Quality SOP & Tech Pitfalls (The Reality Check)

The Lab Report (SOP)
We treat these surplus motors like they’re going into a clean room, because one speck of conductive dust can ruin the encoder.

1. Visual & Mechanical Check: We inspect the shaft for any scoring or rust (a dead giveaway of a returned unit). We check the M23 connector pins for bending. The flange mounting surface is cleaned and checked for flatness.
2. Electrical Integrity: Using a Megger (insulation tester) at 500V DC, we verify winding-to-ground resistance is >100 MΩ. We measure phase-to-phase resistance with a Fluke 87V to ensure all three windings are balanced within 1%.
3. Encoder Live Test: This is the big one. We hook the motor up to a test drive (HCS02) and verify the encoder counts. We rotate the shaft by hand and watch the position value change smoothly. No dropouts, no noise.
4. Run-Out Test: We run the motor at 1000, 2000, and 3500 RPM for 15 minutes each. We monitor bearing noise and temperature rise. If the bearings sound like a bag of marbles, it gets rejected.
5. Packaging: The shaft is coated with anti-corrosion oil, capped, and the motor is packed in a custom foam crate to prevent shipping damage to the fragile encoder housing.

The Engineer’s Warning (Pitfalls)
Here is the trap that kills weekends: The Encoder Protocol Mismatch. The suffix “-D7-” specifies a very particular encoder interface and parameter set. If you swap this motor into a system that previously had a “-D6-” or a different manufacturer’s motor, the drive will likely throw an “F2022 Encoder Error” or worse, spin uncontrollably because the commutation angle is off. I once saw a technician force a mismatched motor to run by tweaking the commutation offset manually. It worked for an hour, then the motor overheated and demagnetized the rotor because the field orientation was wrong. Also, check the shaft key. Some KSM01 variants come with a smooth shaft and a clamp hub, others have a traditional keyway. If your gearbox has a keyed shaft and you order the smooth version, you’re stuck. Always match the mechanical suffix exactly.

Installation & Configuration Guide

Swapping a servo motor is delicate. One wrong move and you scrap a $3,000 encoder.

1. Pre-Installation (⚠️ CRITICAL): Lock out the main 480V AC supply. Wait 10 minutes for the drive capacitors to discharge (LED on drive must be off). Take photos of the motor wiring colors and the encoder pinout if the cables aren’t labeled. Note the mechanical coupling setup.
2. Removal: Support the motor weight! These are heavy. Unbolt the flange carefully. Disconnect the power and feedback cables. Inspect the cable connectors; if the pins are green (corroded), replace the cable assembly, don’t just clean it.
3. Installation: Align the new KSM01 motor. Do not hammer on the shaft end; you will destroy the internal encoder. Bolt the flange evenly in a star pattern. Connect the power (U, V, W) matching the phase sequence. Double-check the encoder cable; forcing the wrong pinout can fry the encoder electronics instantly.
4. Power-On & Tuning: Restore control power (24V) first. Then main power. The drive will detect the motor code (if stored). If not, you must manually enter the motor data sheet values (Rn, Ln, Ke, etc.) from the Rexroth catalog. Run the “Auto-Commissioning” routine. Listen for weird noises. If it vibrates, stop immediately. Verify the holding brake (if equipped) releases correctly.

Compatible Replacement Models

Frequently Asked Questions (FAQ)

Q: Can I use this motor with a Siemens S120 drive?
A: Technically, yes, but it’s painful. You would need to configure the S120 for “1FT7/1FK7 compatible” mode or manually enter all motor parameters (resistance, inductance, back-EMF constant). The encoder (EnDat/Hiperface) might not be natively supported without a specific sensor module. It’s usually cheaper and safer to stick with a Rexroth drive or buy a Siemens motor.Q: My motor makes a grinding noise at high speeds. Is it the bearings?
A: Likely. The KSM01 series uses precision angular contact bearings. If the machine was subjected to high axial loads (e.g., a misaligned belt tensioner), the bearings wear out. At 3500 RPM, a worn bearing sounds like a jet engine. You can replace the bearings, but it requires special tools to preload them correctly. Often, swapping the whole motor is more cost-effective than a botched bearing job.Q: What does the “FW” at the end of the model number mean?
A: “FW” typically indicates a specific winding version or factory modification for a particular OEM (like a packaging machine builder). It shouldn’t affect basic electrical compatibility, but it might indicate a custom shaft length or special paint. Always compare the dimensional drawing of the “FW” unit with your existing one before buying.Q: Is the encoder battery-replaceable?
A: No. The multi-turn absolute encoder in the KSM01 usually relies on a gear mechanism or non-volatile memory that doesn’t require a battery, OR it has a sealed battery pack inside the motor housing. If the “absolute position” is lost, it often means the internal backup failed or the gear slipped. You can’t just pop a CR2032 in there; the motor usually needs to go back to the factory or be replaced.Q: How do I identify if the shaft is keyed or smooth?
A: Look at the 14th/15th character of the model number or check the datasheet. In your model ...35N..., the “N” often denotes a specific shaft configuration. However, visual inspection is king. If the shaft has a slot cut along its length, it’s keyed. If it’s perfectly round with a flat spot for a clamp, it’s smooth. Mismatching this means your coupling won’t transmit torque.Q: Can I run this motor without a feedback cable (open loop)?
A: No. This is a synchronous servo motor. It requires the encoder feedback for commutation. Without the encoder connected, the drive will fault immediately (Commutation Error) and will not energize the phases. Attempting to force it could damage the drive IGBTs.