High-precision Milling Robotic Arm with Secondary Encoders for innovative Manufacturing

The MABI robot arm was developed for milling processes and should therefore have a high level of accuracy. Milling robots from other manufacturers are often converted standard products, which is why they lag behind in terms of accuracy and rigidity. The milling robots from the MAX series are designed to absorb the process forces of milling operations. When compared with similar robots, the differences lie primarily in the high-precision kinematics, the increased rigidity, the use of secondary encoders and the CNC control. Another difference lies in the factory calibration with a measurement protocol specially developed for the milling robots. The system can also be supplied "ready to run".

Our robot arms have been developed for precise machining processes. Materials that are processed by MABI robots are wood, aluminum, steel and CFRP. We can test other materials you require. Due to its precision, the milling robot can of course also be used in other areas. A large area of application is in additive manufacturing. For example, the robot arm can be used to switch between a laser deposition welding head and a milling spindle. This means that work processes can be carried out with one robot arm instead of two machines. At the moment, many of our milling robots are used in companies that have to machine large components, such as in the aviation or automotive industries. Perhaps you have a new area of application for our milling robots. We will be happy to support you in clarifying your application.

Standard robotic systems usually use a single encoder mounted on the motor. The encoder provides speed and position feedback to the controller. This gives us precise position information from the drive side. Due to the backlash of the gears, there is a small deviation on the output side, which increases with each additional axis. To increase the accuracy of the milling robots, the output side is measured with a second encoder. This allows the difference caused by backlash etc. to be readjusted. A secondary encoder and high-precision kinematics are therefore required for an accurate robot arm.

Programming is carried out using NX CAD and CAM software from Siemens. As with CNC machines, the program is created in CAM and then converted into G-code using a post-processor. Alternatively, conventional programming is also possible for simple applications — the SINUMERIK controller offers a variety of standardized cycles that can be used flexibly.

The open Siemens architecture also enables close integration between CAD, CAM and control, which allows complex milling processes to be efficiently mapped. Since the milling robot arm is integrated into the Siemens ecosystem, users benefit from consistent workflows, reduced set-up costs and a high level of process reliability. The robot arm can be fully programmed with G-code, which allows CNC-experienced integrators a seamless introduction to robot-based milling processing.

Each robot arm is measured and calibrated before delivery. To do this, we use a high-precision Leica laser tracker, which precisely detects the robot in various positions.

By means of this measurement method, the kinematic structure of the robot arm is determined with high precision. The parameters determined flow directly into the controller and ensure that the milling robot achieves a high level of repeatability right from the factory. The system is calibrated not only in a static state but also under real movement conditions — a decisive advantage for demanding milling applications with tight tolerances.

Factory calibration includes measuring selected DH parameters and adjusting the kinematically ideal zero position of the axes. The optional ISIOS system supplements this basic calibration with additional functions such as model-based active compensation, dynamic gravity correction and precise recalibration options in the operational environment.

ISIOS offers advantages, particularly for complex milling processes: Plant-based model measurement not only increases accuracy, but also improves their stability over longer operating cycles. ISIOS represents an important extension for users who use the milling robot arm in particularly precise or temperature-critical environments.

Our robotic arm has been specially optimized for milling processes and, with its structural stiffness and repeatability, achieves values that are close to modern portal milling machines. At the same time, it remains flexible to use — our milling robot is an economically attractive alternative, especially for large components.

However, the achievable component accuracy depends largely on the complexity of the processing process, the spindle used, the milling tool and the material properties. In certain cases, classic CNC centers can still be an advantage when it comes to extreme precision requirements. Our milling robot arms, on the other hand, offer an ideal balance between precision, flexibility and investment costs — especially for large-volume or geometrically complex parts.

The selection of a suitable spindle depends largely on the specific application. Both the weight of the spindle and its performance characteristics are decisive. In order to be able to better absorb the dynamic forces during the milling process, we recommend — where technically possible — the use of a spindle that is as lightweight as possible.

It is important that the spindle characteristic (torque, power and speed range) is tailored to the material to be processed and the process. For highly dynamic processing, such as processing plastics or aluminum, spindles with high speeds and low weight are generally preferred. Under Accessories, you will find a selection of spindles that are offered as standard. On request, we can also check the integration of specific spindle models for your application — especially if your milling robot arm is to be used in highly specialized processes.

Yes, we offer feasibility studies to evaluate individual applications. Specially equipped robot cells with the MAX100 and MAX200 models are available for this purpose, in which tests are carried out under real conditions.

Our studies include both geometric and procedural analyses, for example with regard to tool path strategy, processing times and achievable tolerances. After carrying out the tests, we create detailed documentation and discuss the results with you. On request, we can develop a tailor-made test concept that is precisely tailored to your requirements. For companies that want to integrate the milling robot arm into new or non-standardized areas of application, a feasibility study is a valuable planning step.

We deliver our milling robots as completely preconfigured ready-to-run systems. You get the robot arm including control cabinet, milling spindle and SINUMERIK ONE controller — fully coordinated with the associated Siemens software.

Start-up only requires the connection of the prepared components. All system parameters are preconfigured so that no time-consuming basic programming is necessary. The documentation provided and our technical support make initial start-up even easier. For more extensive projects, we recommend working closely with one of our integration partners in order to efficiently utilize the full potential of the milling robot — even for complex automation.