In the field of industrial automation, SCARA (Selective Compliance Assembly Robot Arm) robots play a core role in assembly, handling, dispensing and other processes due to their high speed, high precision and compact structure. The KUKA KR SCARA-2 CS series is a 4-axis robot designed specifically for small and medium-sized loads. Its maximum load can reach 6kg, and its maximum arm span covers 500mm to 700mm. For equipment engineers, how to correctly install, debug, and ensure its long-term stable operation is the key to ensuring production line efficiency. This article will provide you with a detailed practical guide from mechanical installation, electrical connections, precision calibration to daily maintenance.
Product positioning and model analysis: from R500 to R700
The KUKA KR SCARA-2 CS series includes multiple sub models, with the main difference being the arm span length. Understanding the naming conventions of models is the first step in selection and maintenance.
KR 6 R500 Z200-2 CS: Maximum arm span of 500mm, Z-axis stroke of 200mm.
KR 6 R600 Z200-2 CS: Maximum arm span of 600mm, Z-axis stroke of 200mm.
KR 6 R700 Z200-2 CS: Maximum arm span of 700mm, Z-axis stroke of 200mm.
Among them, "KR" represents KUKA Robot, "6" represents maximum load of 6kg, "R" represents Reach (arm span), and "Z" represents Z-axis (vertical axis) stroke. All models come standard with KR CS Box-2 controller, with a protection level of IP20, suitable for clean industrial environments.
It is worth noting that the series also offers the C01 variant. The C01 version has undergone specific optimizations based on the standard version, with differences in interface layout and cable configuration. For example, the standard version of interface A1 includes motor cables (X30), data cables (X31), grounding conductors, and four pneumatic interfaces (AIR1-AIR4). The interface A1 of the C01 version is more concise, mainly including the battery, data cable (X31), and motor cable (X30). Its pneumatic interface and user interface have been rearranged on interface A2 (arm). Engineers must first confirm the specific model of the equipment when planning and wiring to avoid installation delays caused by interface mismatches.
Precision cornerstone: installation foundation and mechanical assembly
The accuracy of SCARA robots is highly dependent on the rigidity of the installation foundation. According to technical data, the KR SCARA-2 CS series adopts a ground installation method, with a base installation surface size of 262mm x 190mm and a weight of approximately 20-21kg.
1. Installation foundation requirements
The installation base must be made of steel and the installation surface thickness must be at least 16mm. The flatness tolerance should be controlled within 0.4mm. If the installation surface is not flat, the base may undergo slight deformation when tightening the anchor bolts, directly causing the robot's zero point to shift or vibration during movement, seriously affecting the repeat positioning accuracy (XY axis ± 0.02mm).
2. Installation steps and precautions
The installation process consists of two steps: fixing the installation base and installing the robot body.
Positioning and fixing: First, place the installation base horizontally, with a maximum allowable tilt angle of 5 °. Subsequently, two positioning pins must be inserted into the base to ensure precise alignment between the robot body and the base.
Robot body installation: Use a forklift or two people to work together to vertically and slowly lower the robot onto the installation base. Special attention should be paid here: if the vertical position is not maintained during the descent process, it is highly likely to damage the positioning pin.
Tighten bolts: Use 4 M8 screws, matched with flat washers and spring washers, and tighten diagonally alternately. After 100 hours of initial startup or re debugging, the tightening torque of these 4 M8 screws must be checked.
Electrical Connections and Interface Configuration: Differences between Standard Version and C01 Version
Electrical connections are the nerves and blood vessels of robot systems. The connection cables of KR SCARA-2 CS series mainly include motor cables, data cables, and grounding conductors.
The Importance of Grounding Conductors
According to DIN EN 60204 standard, a low resistance connection must be established between the robot and the control cabinet using a grounding conductor. The grounding conductor is optional and needs to be connected by the user themselves. The connection point is located on the robot base and uses M4 ring cable lugs. Do not rely on emergency or safety stops to cut off power, as some components may still be charged.
2. Layout of interfaces A1 and A2
Interface A1 (rear of base): This is the main electrical and pneumatic interface. The standard version includes:
X30: Motor power interface (WEIPU WS28 series).
X31: Encoder data interface (WEIPU WSF28 series).
X40:15 pin D-sub user I/O expansion interface.
X74: 8-pin M12 X-code Ethernet expansion interface.
AIR1-AIR4: Pneumatic interface, corresponding to Ø 4mm and Ø 6mm trachea respectively.
Interface A2 (Arm): The standard version includes motor indicator lights, brake release buttons (for shaft 3 and shaft 4), as well as X94 (8-pin M12 Ethernet) and X41 (15 pin D-sub) user interfaces.
For version C01, interface A1 has removed the pneumatic interface and user interface, retaining only the battery, X30, and X31. This means that in version C01, all pneumatic and user I/O connections need to be made through interface A2 on the arm. This design reduces the cable density at the back of the base, making it easier to route cables in narrow spaces.
3. Cable wiring specifications
Bending radius: When fixing and laying motor cables, the minimum bending radius shall not be less than 55mm; for data cables, it shall not be less than 45mm.
Electromagnetic compatibility: Motor cables and data cables must be separately laid in their respective metal cable trays to prevent electromagnetic interference.
Reserved space: It is recommended to reserve at least 200mm of space behind interface A1 for connecting cables.

Core maintenance: Zero point calibration and battery replacement
The absolute accuracy of SCARA robots depends on the zero position of each axis. After replacing the motor, reducer, cable, or battery, the zero point may shift and must be recalibrated.
1. Zero point calibration (Mastering)
Calibration of A1 and A2 axes requires specialized calibration tools (Article number: 0000-396-617). The steps are as follows:
Insert the calibration tool into the calibration slots of A1 and A2 axes.
Gently move the robot to align the two calibration slots and fully embed the calibration tool.
In the calibration page of KUKA. ControlStudio or smartPAD touch, select "Set Current" to set the zero point.
Remove the calibration tool and test the program in T1 mode.
2. Battery replacement
The KR SCARA-2 CS series is equipped with a backup battery inside the base for storing encoder data in the event of a power outage. According to the maintenance schedule, the battery unit needs to be replaced once a year. If the battery is depleted, the zero point data will be lost and a new zero point calibration must be performed. Therefore, it is recommended to include battery replacement in the annual preventive maintenance plan.
Manual movement and brake release operation
In debugging or emergency situations, it may be necessary to manually move the robot. KR SCARA-2 CS offers two ways:
Servo Free mode: activated through KUKA. ControlStudio. In this mode, the brake of axis 1 and axis 2 can be released through software.
Brake release button: located on the arm (interface A2). Press and hold this button to release the brake of shaft 3 and shaft 4.
Safety warning: When the brake release button is pressed, axis 3 (Z-axis) may fall freely due to the weight of the load. When operating, it is necessary to hold the load or tool with your hands to prevent falling and causing personal injury or equipment damage. In addition, when manually moving axis 1 and axis 2, it is also important to note that the robot may experience unexpected movements due to gravity or inertia.
Stopping distance and time: core data for safety design
When planning safety fences and assessing risks, stopping distance and stopping time are key parameters. According to DIN EN ISO 10218-1 standard, stopping distance=reaction distance+braking distance.
KUKA provides two types of stop category data:
Stop 0 (Category 0): The driver immediately loses power, and the short-circuit brake and electromechanical brake engage simultaneously. Usually triggered by robot power outage, CPU failure, or fatal drive system failure.
Stop 1 (Category 1): The robot is controlled to stop along the original path, and then the drive is powered off and the brake is applied. Usually triggered by emergency stop, safety input, or control failure.
Taking KR 6 R500 Z200-2 CS as an example, under 100% project and rated load:
Stop 0: Axis 1 stops at a distance of approximately 46.42 ° with a stop time of 0.21s; Axis 3 stops at a distance of 58.47mm with a stop time of 0.08s.
Stop 1: Axis 1 stops at a distance of approximately 46.56 ° with a stop time of 0.17s; Axis 3 stops at a distance of 85.07mm with a stop time of 0.12s.
Engineering suggestion: The actual stopping distance may vary due to load, speed, and wear. It is recommended to check the stopping distance at least once a year, especially in high load or high-frequency Stop 0 shutdown applications. The design of safety fences must be based on the worst-case stopping distance and combined with personnel response time to ensure sufficient safety clearance.
Scrap and Disposal: Environmental Protection and Compliance
When the robot reaches the end of its service life, it must be disassembled and recycled according to the material type. The main material composition of KR SCARA-2 CS includes:
Metal: cast aluminum (base, arm, connecting rod), copper (cable), steel (gearbox, ball screw, screw).
Plastic: ABS, PC (cover plate), NBR (O-ring), PU (hose), PUR (cable sheath).
Electronic components such as EDS and motors need to be treated as electronic waste and do not require further disassembly.
Special attention: The gearbox and ball screw contain lubricating grease (such as Harmonic Drive 4B No.2, THK AFB-LF), and local environmental regulations should be followed when disposing of them. The latest safety data sheet can be obtained from the manufacturer.
