Product Core Brief
- Model: MSK030C-0900-NN-M1-UG1-NNNN, OEM part number R911308684
- Brand: REXROTH (Bosch Rexroth Indramat IndraDyn S MSK series)
- Series: MSK compact permanent magnet synchronous servo motor family
- Core Function: Deliver ultra-low inertia high-speed positioning for vertical pick-and-place, small vertical gantries, and lifting axes with integrated power-off brake and multiturn absolute position feedback.
- Product Type: 030 frame C-length compact servo motor, natural convection cooling, 1 Nm 24 V holding brake, plain sealed shaft, M1 Hiperface multiturn encoder
- Key Specs: 0.8 Nm continuous stall torque | 9000 rpm max mechanical speed | 6.8 A peak current | 1 Nm integral holding brake | IP65 full housing protection | Condition: New Unused Surplus
- Suffix breakdown: 030 = frame size; C = extended stator stack; 0900 = unique winding electrical code; NN = natural convection, no auxiliary blower; M1 = optical Hiperface multiturn absolute encoder; U = 240° rotatable side connector housing; G1 = smooth plain sealed shaft + integrated 1 Nm 24 V holding brake; NNNN = no optional add-on hardware
Product Introduction
The REXROTH is a compact high-speed servo built for vertical load axes that require power-off load retention, paired with HMD dual-axis inverters and coordinated by CML40 SERCOS motion PLCs. Its built-in multiturn Hiperface encoder eliminates mandatory homing after every full machine power cycle.This unit differentiates from UG0 brake-less variants by adding a factory-integrated 1 Nm fail-safe holding brake for vertical lifting axes, though unit mass rises by 0.2 kg due to the brake coil assembly. OEM field data lists its rated MTBF at 47,000 operating hours under continuous 9000 rpm cyclic light vertical loading at 40 °C cabinet ambient.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Continuous stall torque (100 K temp rise) | 0.8 N·m |
| Peak short-duration overload torque | 4.0 N·m (0.5 s maximum duty cycle) |
| Maximum mechanical rotational speed | 9000 rpm |
| Continuous RMS standstill current | 1.7 A |
| Peak overload RMS current | 6.8 A |
| Winding inductance (20 °C) | 14.1 mH |
| Rotor moment of inertia | 0.00003 kg·m² ultra-low inertia |
| Cooling system | Natural surface convection (NN suffix, no blower) |
| Encoder model (M1) | Optical Hiperface multiturn absolute |
| Encoder resolution | 128 signal periods single-turn, 4096 full revolutions multiturn tracking |
| Electrical connector housing | U-type side exit, 240° rotational adjustment for cable routing clearance |
| Output shaft (G1) | 9 mm diameter smooth plain shaft, integrated IP65 contact seal |
| Holding Brake Full Specs | 1 Nm static holding torque; 24 V DC coil; 0.79 A coil draw; power-off engaged fail-safe design |
| Flange mounting dimensions | 030 standard compact square flange, four M3 mounting hole pattern |
| Full unit net weight | 2.1 kg |
| Enclosure environmental rating | IP65 full motor housing and shaft seal |
| Winding insulation class | F grade (155 °C maximum winding operating temperature) |
| Continuous operating ambient temp | 0 °C to +40 °C full rated speed; linear performance derate above +40 °C |
| Storage / transport temperature range | -20 °C to +70 °C, non-condensing 5–95% RH |
| Compliance certifications | CE, UL, SEMI S2, EN61000 industrial EMC filtering for cleanroom plasma processing equipment |
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Cross-reference serial number against Rexroth OEM R911308684 part database; inspect factory red shaft protective cap seal integrity, check connector housing for cracks, encoder rear cover for scratches, and brake coil terminal pins for oxidation. Photograph rotatable connector side exit orientation for field installation reference.
- Live Functional Test: Mount motor to low-inertia dynamometer bench paired with HMD01.1N dual-axis drive simulator; run 24 hour cyclic 0–9000 rpm speed ramp and 0–4 Nm overload load profiles. Use a Fluke 115 signal logger to track three-phase winding current balance, absolute encoder position retention, and brake coil pull-in/release timing.
- Electrical Parameter Test: 500 V Megger insulation test between stator windings, brake coil, and motor chassis ground (pass threshold >10 MΩ); verify three-phase winding resistance imbalance stays below 2% at 25 °C ambient temperature.
- Encoder & Brake Verification: Establish full Hiperface bidirectional communication handshake with servo drive firmware; test full 240° connector housing rotation without pin strain or signal dropout; validate 1 Nm static brake holding capacity with torque fixture after 12 hour power-off retention test.
- Final QC & Packaging: Retain factory plastic shaft and connector dust caps; seal unit in anti-static PE foam lined bag, apply dated QC Pass label listing torque linearity, encoder position error, and brake holding torque test metrics before rigid carton shipping.
Replacement Pitfall Guide
❗ UG0 / UG1 Brake Variant Mismatch Risk: UG0 brake-less motors cannot replace this UG1 braked unit on vertical axes. Removing the brake circuit wiring will trigger persistent brake open-circuit fault codes on the paired servo drive, and unlatched vertical loads will drop during power loss events. Only deploy UG0 hardware on strictly horizontal non-falling-load axes.❗ Connector Rotation Cable Interference Risk: The U-type 240° rotatable side connector must be pre-positioned to avoid cabinet structural interference. Fixed-side non-rotatable motor variants require full cable harness rework if routing paths conflict post-swap. Photograph original cable bend radius before disconnecting wiring.❗ Plain Shaft Seal Damage Hazard: Removing the factory red plastic shaft cap prior to coupling installation scratches the integral IP65 contact seal. Damaged seals allow cleanroom particulate ingress that accelerates bearing wear and creates periodic positioning jitter within 3,000 operating hours.❗ Drive Winding Parameter Mismatch Risk: Winding code 0900 has unique resistance and inductance values. Installing this motor into drives loaded with alternate MSK030C winding parameter sets creates unstable current loops, audible stator vibration, and overcurrent trips during fast acceleration to 9000 rpm.❗ ESD Encoder Circuit Damage: The rear Hiperface optical encoder ASIC has low electrostatic discharge tolerance. Always rest the unit on a grounded anti-static mat during connector disconnection or encoder housing inspection, especially in low-humidity cleanroom production environments.Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
Compatibility Matrix
- MSK030C-0900-NN-M1-UG0-NNNN → : Needs Adaptation — add 24 V brake control wiring to servo drive logic, enable brake sequence logic inside motion program for vertical load safety
- HMD01.1N-W0020-A-07-NNNN → : Direct — native Hiperface encoder input and 6.8 A peak per-axis drive rating fully matches motor electrical specs
- CML40.2-SP-330-NA-NNNN-NW → : Direct — SERCOS II motion bus natively processes M1 multiturn absolute position data without auxiliary signal conditioning
- DKC11.1-040-7-FW → : Direct — ECODRIVE firmware includes pre-stored parameter library for winding code 0900 MSK braked motors
