In the fields of high-speed sorting, packaging, picking and placing, and light load assembly, parallel robots have become important execution units in automated production lines due to their compact structure, fast pace, and high repeatability positioning accuracy. The KUKA KR 15 DELTA-2 V2 series, including applicable variants such as KR 15 D1200-2 and KR 15 D1600-2, continues the high dynamic response characteristics of parallel robots. The installation quality directly affects the stability of subsequent operation, cable life, and maintenance costs. This article focuses on the mechanical installation, cable connection, upper arm leveling, dynamic platform assembly, A4 cable fixation, and inspection points of this series of robots, forming a technical guide for on-site engineers.
Preparation and safety principles before installation
The installation, commissioning, and maintenance of KUKA KR 15 DELTA-2 V2 must be carried out by trained and qualified personnel. Operators should be familiar with safety regulations and able to identify potential risks. Before installation, it should be confirmed that the control cabinet, robot body, cable components, spring components, cable clamps, installation screws, and lifting tools are complete. The robot body usually includes electrical installation, base, upper arm, A4 cable, forearm, moving platform, and installation flange. The installation site should be kept clean, especially the bottom surface of the installation plate and the installation surface of the robot, to avoid chips, oil stains or burrs affecting the positioning accuracy.
In terms of tools, it is recommended to prepare torque wrenches, cranes or hoists, lifting rings, ropes, locating pins, hex wrenches, cleaning agents, dust-free cloths, and zip ties. Special attention should be paid to the fact that some fasteners are provided by the customer, such as the 12 M8x30-10.9 hex socket screws used for installing the robotic arm. All fasteners should be tightened according to the specified torque values and cannot be estimated based on experience. Common torques include: lifting ring 20 Nm, mounting plate M8x30 screw 31 Nm, upper arm cable clamp M4x50 screw 1.2 Nm, forearm cable clamp M4x60 screw 1.2 Nm. Excessive torque may damage threads or castings, while insufficient torque may cause loosening and cable wear.
Lifting and foundation treatment
Before lifting the robot, three lifting rings should be tightened at the indicated position on the base panel. The lifting ring must be fully screwed in to ensure reliable force bearing. Then connect the rope to the lifting ring and lifting equipment, with a tightening torque of 20 Nm at the connection. During the lifting process, the robot should be kept stable to avoid sudden impacts and swings. Due to the multiple forearms and moving platforms of the parallel robot, the A4 moving platform should not be suspended for a long time to bear excessive weight during lifting. If necessary, support fixtures should be used to support the moving platform to prevent the connecting cables from being excessively pulled.
Two grounding cables need to be fixed at the rear of the base. Grounding is the foundation of electrical safety, and it is necessary to ensure that the grounding terminal is clean and in good contact. If the grounding is poor, it not only affects electromagnetic compatibility, but may also pose safety risks in the event of a fault. After completing the lifting, move the robot to the vicinity of the installation position and prepare to dock with the rack and mounting plate.
Cable installation and interface correspondence
Cable installation is a crucial step before debugging. There are usually motor cables and data cables between the control cabinet and the robot body. The motor cable interface corresponds to the markings: the control cabinet side involves interfaces such as XD10. x and XD20. x, and the robot side corresponds to X30. The data cable is connected from XF21 to X31. When wiring on site, it must be strictly inserted according to the cable markings and cannot be interchanged at will. Incorrect connection of motor cables may lead to servo alarms, motor abnormalities, and even damage; Connecting the data cable incorrectly may result in communication failure, abnormal encoder data, or system failure to start.
Before wiring, it should be confirmed that the control cabinet is powered off and the locking and tagging procedure should be executed. Pay attention to the direction when inserting the connector to avoid bending the pins. The cable should have appropriate allowance, but should not form large loops that may be caught by moving parts. Grounding cables, motor cables, and data cables should be routed separately to reduce electromagnetic interference. After completing the wiring, double check if all interfaces are in place and if the locking mechanism is securely fastened.
Upper arm horizontal adjustment
Before fixing the robotic arm to the mounting plate, it is necessary to first adjust the posture of the upper arm. After powering on the control cabinet and starting the system, use a teaching pendant to adjust the upper arms of A1, A2, and A3 to a horizontal position. The purpose of this step is to ensure a smooth fit between the robot installation surface and the installation plate, avoiding difficulties in inserting the positioning pin or installation stress caused by improper angle of the upper arm. When adjusting, slowly jog and observe whether the movement of each axis is stable and whether there is any abnormal noise.
It should be emphasized that when the upper arm is not connected to the forearm or the spring component is not installed, the A1, A2, and A3 upper arms may have a tendency to sag due to gravity. Operators should always hold or support their upper arms to avoid sudden drops that may cause pinch injuries or collisions. After completing the horizontal adjustment, maintain the posture and prepare to dock with the installation board.
Install the robotic arm onto the mounting plate
When installing the robotic arm onto the rack mounting plate, first clean the bottom surface of the hexagonal mounting plate. If there are impurities on the bottom surface of the installation board, it will cause uneven force on the robot base, affecting accuracy. Then use a crane to lift the robotic arm near the frame and insert the three positioning pins into the interface board. The function of the positioning pin is to pre position and ensure that the robot base is aligned with the mounting plate hole. After inserting the positioning pin, use 12 M8x30-10.9 hex screws to fix the robotic arm to the frame with a tightening torque of 31 Nm.
When tightening screws, a diagonal cross sequence should be used, gradually increasing the torque step by step to avoid deformation of the base caused by excessive tightening on one side. During the installation process, it is necessary to support the A4 moving platform to avoid the weight of the moving platform hanging on the connecting cables. The A4 platform is usually connected to the upper arm through forearm and spring components. If it is suspended and subjected to force, it may cause internal cable damage, ball head wear, or spring deformation. After installation, check if the base and mounting plate are in good fit and if there are any gaps.

Installation of forearm, spring components, and moving platform
The forearm and spring components are important components of the parallel robot motion chain. Install the spring component onto the casting first during installation. Then install the first forearm and connect it to the upper arm and the motion platform, paying attention that the orange mark on the forearm should be close to the upper arm. Then install the second forearm, also bringing the orange mark closer to the upper arm. The ball head D20 must be coordinated with the upper arm and the moving platform to ensure a good fit of the ball head.
When installing the moving platform, install the spring component on the casting of the moving platform, with the spring opening facing upwards. Do not fully stretch the spring to avoid exceeding its elastic range. Connect the two forearms to the moving platform in the order of A1, A2, and A3 axes, and ensure that the direction of the cable outlet conforms to the diagram. The opening direction of the spring at different positions must be strictly followed according to the markings. Some views indicate that the spring opening is facing downwards, while others require it to be facing upwards. Reversing the installation can cause abnormal force, abnormal noise, or even breakage of the spring.
After installation, visually inspect whether the ball head snugly fits the upper arm and A4 platform. If gaps are found, do not forcefully tighten and contact KUKA support. The clearance between the ball heads can cause return errors, vibrations, and noise, affecting the accuracy and lifespan of the robot.
A4 cable and cable clamp layout
The A4 cable must be installed on the A1 arm. Customers can adjust the direction of the base board according to the working environment to avoid wiring interference, but must not change the basic path on the A1 arm. When installing the upper arm cable clamp, place the cable clamp at the white marked line on the A1 upper arm and fix it with 4 M4x50 screws with a torque of 1.2 Nm. Then align the white mark of the A4 cable with cable clamp ① and fix it with 2 M4x50 screws with a torque of 1.2 Nm. Ensure that the cable is parallel to the upper arm before installing cable clamp ②. The installation direction of cable clamps must avoid friction between cables and other structures.
When installing the forearm cable clamp, align the white cable with the white marking line ① on the A1 forearm, and fix the forearm cable clamp with 2 M4x60 screws with a torque of 1.2 Nm. Ensure that the cable is parallel to the forearm, and then install cable clamps ② and ③ in sequence. The direction of the cable clamp is also based on the principle of avoiding friction. If the direction is incorrect, the cable of the robot may interfere with the forearm, spring or protective plate during high-speed movement, causing insulation damage, signal interruption or even short circuit.
User wiring must not bundle, cross, or interfere with A4 cables. It is recommended to bundle the user cable onto other axes and reserve sufficient length for moving parts. The A4 cable is crucial for communication and power supply on the mobile platform, and any additional pulling may shorten its lifespan. After completing the wiring, the robot should be manually moved at a slow speed to observe whether the cable moves smoothly, whether there are scratches or excessive bends.
Inspection, Testing, and Common Problems
After installation, perform a system check. Firstly, confirm that all screw torques meet the requirements, especially the M8 screws on the mounting plate with a torque of 31 Nm, lifting rings with a torque of 20 Nm, and cable clamps with a torque of 1.2 Nm. Secondly, check whether the grounding cable, motor cable, and data cable connections are correct and secure. Then power on, run each axis at low speed, and observe for any abnormal noise, vibration, or alarm. The teaching pendant can display the position and current of each axis. If the current of a certain axis is abnormally high, it may be due to mechanical installation stress or cable interference.
Common problems include: cable friction caused by incorrect cable clamp direction; Reverse or twisted installation of spring components; The ball head is not properly attached; The upper arm is not leveled, resulting in misalignment of the installation hole; Poor grounding leads to communication interference; Insufficient torque of screws leads to looseness. The treatment method is to readjust according to the identification, replace the damaged cable, recalibrate the upper arm level, and tighten it according to the torque table. If the gap between the ball heads cannot be eliminated, the use should be stopped and KUKA support should be contacted.
