The REXROTH R911308683 MSK030C-0900-NN-M1-UG0-NNNN is a compact synchronous servo motor from the IndraDyn S MSK family, developed for high-speed and high-precision motion control in modern industrial automation systems. It is designed for applications where machine builders need responsive dynamic behavior, stable torque delivery, compact installation dimensions, and reliable long-term operation. As part of the MSK030C-0900 platform, this motor combines a maximum speed of 9000 min⁻¹ with low rotor inertia and a lightweight structure, making it particularly suitable for fast indexing systems, compact handling units, small servo axes, packaging machinery, electronic assembly equipment, and other precision-driven machines where control quality is more important than oversized output.
Unlike general-purpose motors, the MSK030C-0900 is built for servo-controlled environments in which positioning accuracy, speed stability, and fast acceleration are critical. The technical data published for the MSK030C-0900-NN version shows a continuous standstill torque of 0.8 Nm, a maximum torque of 4.0 Nm, a maximum speed of 9000 min⁻¹, and a rotor inertia of 0.00003 kg·m². These values indicate a motor optimized not for sheer size, but for responsive axis movement and precise motion behavior. Its verified motor weight is approximately 1.9 kg for the basic version, which is an advantage for machine concepts that must reduce moving mass and simplify mechanical integration.
Key Technical Data
| Item | Specification |
|---|---|
| Brand | Rexroth |
| Order Number | R911308683 |
| Model | MSK030C-0900-NN-M1-UG0-NNNN |
| Product Family | IndraDyn S MSK |
| Motor Type | Synchronous servo motor |
| Maximum Speed | 9000 min⁻¹ |
| Continuous Torque at Standstill 60 K | 0.8 Nm |
| Maximum Torque | 4.0 Nm |
| Continuous Current at Standstill 60 K | 1.5 A |
| Maximum Current | 6.8 A |
| Torque Constant at 20 °C | 0.58 Nm/A |
| Voltage Constant at 20 °C | 35.6 V/min⁻¹ |
| Rotor Inertia | 0.00003 kg·m² |
| Thermal Time Constant | 12.0 min |
| Sound Pressure Level | <75 dB[A] |
| Net Weight | 1.9 kg |
| Operating Ambient Temperature | 0 to 40 °C |
| Protection Class | IP65 |
| Insulation Class | 155 |
The specifications in the table above are based on the published MSK030C technical data and Rexroth product reference for R911308683. The documentation also notes that the weight value for the basic motor is 1.9 kg, while higher values may apply to versions equipped with a holding brake.
Engineering Value in Real Machine Design
A major strength of the REXROTH MSK030C-0900 motor is the balance it offers between high rotational speed and compact mechanical design. In small and medium machine axes, designers often face a trade-off between dynamic performance and installation space. A motor that is too large adds inertia and limits acceleration, while a motor that is too small may struggle with overload peaks. The MSK030C-0900 sits in a useful engineering position: its maximum torque of 4.0 Nm provides short-term overload capability, while its low rotor inertia supports quick response during start-stop cycles, speed changes, and repeated positioning tasks. Based on the published speed and inertia values, this configuration is especially suitable for axes that require agile motion rather than heavy-duty continuous torque. That is a practical advantage in feeders, rotary tables, light conveyors, dosing systems, and compact servo modules.
Another important benefit is mass reduction. With a verified basic motor weight of around 1.9 kg, the MSK030C-0900 can help lower the moving weight of a machine assembly. This is relevant not only for robot end axes and compact handling devices, but also for machine builders working on energy efficiency and vibration control. Lower moving mass usually makes it easier to achieve faster cycle times, reduce structural stress, and improve control stability when paired with a properly matched drive and tuning strategy. In practical terms, this means the motor is not simply “small”; it supports a more efficient motion system architecture.
Application-Oriented Benefits
| Application Need | How MSK030C-0900 Helps |
|---|---|
| Fast cycle time | High maximum speed supports rapid motion sequences |
| Precise positioning | Servo design supports accurate closed-loop motion control |
| Compact machine layout | Small frame and low mass simplify integration |
| Responsive acceleration | Low rotor inertia favors dynamic axis response |
| Clean industrial operation | IP65 protection supports use in demanding environments |
| Stable thermal behavior | Documented thermal characteristics support predictable operation |
| Reduced mechanical burden | Light motor mass helps reduce moving load |
The application value listed above is derived from the published motor characteristics such as maximum speed, low rotor inertia, weight, and IP65 protection. The performance conclusions are engineering inferences based on those verified values, not unsupported marketing claims.
Suitability for Precision Automation
In packaging and light assembly equipment, servo motors are often selected not by headline power alone, but by how well they support repeatable motion. The MSK030C-0900 is a strong candidate for machines that must execute short repetitive movements with accurate timing. Examples include label feed mechanisms, indexing star wheels, small transfer systems, medical device assembly modules, semiconductor support equipment, and precision inspection stations. In these environments, engineers typically prefer motors that can accelerate quickly, settle smoothly, and avoid excessive size. The combination of 9000 min⁻¹ maximum speed and low inertia gives this model a clear advantage where rapid motion transitions matter.
The motor also offers a practical environmental specification. The technical data lists IP65 protection and an operating ambient temperature range of 0 to 40 °C. For machine builders, this matters because it supports installation in enclosed industrial machinery where dust resistance, splash resistance, and stable thermal behavior are important. It does not mean the motor is intended for every extreme environment, but it does indicate a robust protection level for normal industrial automation use. The insulation class is listed as 155, which further supports dependable operation under properly engineered electrical and thermal conditions.
Selection Considerations for Buyers and Integrators
When purchasing a servo motor such as the REXROTH R911308683, the most important selection principle is not simply whether the motor can run, but whether it matches the load profile, drive system, feedback requirements, and installation envelope of the target machine. The published MSK030C-0900-NN data indicates a motor designed for compact, high-speed, precision-oriented applications. That makes it a good fit for buyers seeking original Rexroth servo technology for retrofits, spare parts replacement, or new machine builds where low weight and dynamic motion are priorities. At the same time, engineers should still confirm shaft, connector, encoder, flange, and drive compatibility before final ordering, especially in projects where the exact suffix configuration matters.
For procurement teams, the order number R911308683 is the most direct reference when identifying this motor in documentation, quotations, and technical discussions. Using the exact order number together with the full model code reduces the risk of mismatch during sourcing and replacement. This is particularly important in industrial service work, where one missing suffix can affect compatibility with the original drive package or machine harness.
Conclusion
The REXROTH R911308683 MSK030C-0900-NN-M1-UG0-NNNN is a compact and technically refined synchronous servo motor for modern precision automation. Its verified data shows a lightweight 1.9 kg motor platform, 9000 min⁻¹ maximum speed, 0.8 Nm continuous standstill torque, 4.0 Nm maximum torque, IP65 protection, and low rotor inertia. These characteristics position it as an effective solution for high-speed, space-sensitive, and precision-controlled machine axes. Rather than competing as a large power motor, it delivers value through responsiveness, integration efficiency, and motion quality. For buyers, integrators, and machine builders seeking an original Rexroth servo motor for compact automation systems, this model represents a practical and high-quality choice.
