KUKA KR SCARA HO Assembly and Maintenance

KUKA KR SCARA HO Assembly, Debugging, and Maintenance Practical Guide

KUKA KR SCARA HO is a four axis SCARA robot series designed for sanitary applications, mainly consisting of two models: KR 6 R700 Z170 HO and KR 13 R850 Z340 HO. They are commonly used in tool handling, fixture operation, parts assembly, secondary food packaging, and general industrial handling scenarios. HO stands for Sanitary Oil, suitable for environments such as the secondary food industry that require lubrication and hygiene. This series is usually paired with the KR C5 micro-2 or KR C5 micro controller, and consists of a robotic arm, controller, connecting cable KUKA smartPAD-2、 Software, options, and accessories constitute a complete robot system.

For engineers, what truly affects equipment lifespan and production line stability is often not a single parameter, but rather whether installation, safety integration, cable layout, brake release, maintenance cycles, and troubleshooting are in place. Below, from the perspective of engineering implementation, the assembly, debugging, maintenance, and common problem handling points of KUKA KR SCARA HO are systematically organized.

Security compliance is a prerequisite for integration

KUKA KR SCARA HO is a partially completed machinery that must be integrated into a complete system and meet the EU Machinery Directive and local regulations before it can be put into operation. The system integrator needs to complete risk assessment, implementation of safety functions, installation of safety protection devices, issuance of EC conformity declaration, and CE marking. If the safety function is removed or disabled, it is prohibited to operate the robot.

The danger zone is composed of both the workspace and the stopping distance. The stopping distance is equal to the reaction distance plus the braking distance, and is part of the danger zone. The document provides the stopping distance and time for STOP 0 and STOP 1, which are used for the layout of safety fences, safety gates, and light barriers. The safety protection device must be located outside the danger zone, and during the stopping process, the robotic arm will still move within the danger zone, so the fence cannot be installed directly against the theoretical working boundary.

Special attention should be paid to safety warnings: Do not stand under the robot arm; The motor and brake will generate electromagnetic fields, and the wearer of implantable medical devices should maintain a distance of at least 300 mm from the motor and brake; After the motor runs, the temperature may be high, which may cause burns. Protective gloves should be worn; External keyboards and mice can only be used for debugging or maintenance, with the drive turned off and no one in the danger zone, and must be removed after use. After modifying the robot, program, or external axis, it must be tested in T1 mode first. T1 is in manual deceleration mode, with a speed not exceeding 250 mm/s; T2 is a manual high-speed mode, only used for specific testing and not allowed to be used in teaching and programming.

Technical data and selection comparison

KR 6 R700 Z170 HO and KR 13 R850 Z340 HO are both four axis robots, installed on the ground with a protection level of IP54. The positioning of the two is different, and when selecting, the focus should be on comparing the load, arm span, repeatability, and weight.

Project KR 6 R700 Z170 HO KR 13 R850 Z340 HO

Axis number 4 4

Rated load 3 kg 6 kg

Maximum load 6 kg 13 kg

Maximum arm span 700 mm 850 mm

Weight approximately 22 kg, approximately 55 kg

Repetitive accuracy XY ± 0.02 mm ± 0.025 mm

Repetitive accuracy Z ± 0.01 mm ± 0.01 mm

Repetitive accuracy R ± 0.01 °± 0.01 °

Work envelope volume 0.203 m ³ 0.674 m ³

Noise<75 dB (A)<80 dB (A)

Controller KR C5 micro-2/KR C5 micro KR C5 micro-2/KR C5 micro

The axis motion range of KR 6 is A1 ± 132 °, A2 ± 145 °, A3-170 mm to 0 mm, A4 ± 355 °; The speed under rated load is approximately 420 °/s for A1, 720 °/s for A2, 0.95 m/s for A3, and 2000 °/s for A4. The A2 speed of KR 13 is approximately 645 °/s, 1.1 m/s for A3, and 2700 °/s for A4. The load diagram shows that the larger the load, the smaller the allowable distance between the center of gravity of the load. KR 6 has a rated load of 3 kg, with a maximum of 6 kg; KR 13 has a rated load of 6 kg, with a maximum of 13 kg. If the load center of gravity deviates significantly, the mass moment of inertia must be recalculated, otherwise it will accelerate the wear of the motor and gearbox, and even cause vibration and positioning abnormalities.

In terms of flange load, KR 6 has axial force F (a) of about 116 N, radial force F (r) of about 203 N, overturning moment M (k) of about 24 Nm, and flange torque M (g) of about 5 Nm during operation; F (a) of about 309 N, F (r) of about 297 N, M (k) of about 20 Nm, and M (g) of about 12 Nm during emergency stop. KR 13 has F (a) of about 150 N, F (r) of about 600 N, M (k) of about 30 Nm, and M (g) of about 25 Nm during operation; F (a) of about 500 N, F (r) of about 600 N, M (k) of about 30 Nm, and M (g) of about 25 Nm during emergency stop. g) About 40 Nm. The tool design must be able to withstand these loads for a long time.

In terms of basic load, when installing KR 6 on the ground, the normal vertical force is about 319 N, with a maximum of 562 N, the normal horizontal force is about 497 N, with a maximum of 586 N, the normal overturning moment is about 214 Nm, with a maximum of 314 Nm, and the normal torque around A1 is about 143 Nm, with a maximum of 284 Nm. KR 13 has a normal vertical force of about 650 N, with a maximum of 1000 N, a normal horizontal force of about 1250 N, with a maximum of 1650 N, a normal overturning moment of about 650 Nm, with a maximum of 650 Nm, and a normal torque around A1 of about 350 Nm, with a maximum of 580 Nm. When designing and installing the foundation, sufficient safety margin must be left.

Installation base and mechanical installation

The installation base must be prepared by the user, usually using a steel structure with a minimum installation surface thickness of 16 mm and a maximum allowable deviation of 0.4 mm in flatness. KR 6 uses 4 M8 screws, and KR 13 uses 4 M12 screws. Before installation, it should be confirmed that the robot is in the transport position, the foundation surface is flat, the connecting cables and ground wires have been arranged near the robot, and forklifts or lifting equipment can freely approach.

The installation steps include: determining the base position according to the work envelope; Place the base on the base and check for levelness, with a maximum allowable deviation of 5 °; Insert the positioning pin and confirm its firmness; Use lifting equipment to vertically lower the robot onto the base to avoid tilting and damaging the positioning pin; Insert washers and screws; Tighten diagonally. KR 6 uses M8 screws, KR 13 uses M12 screws. Screws with a strength grade of 10.9 or above, stainless steel grade 70 or 80 screws, and screws with testing certification can usually only be tightened once to the rated torque, and should be replaced after loosening.

Connecting cables, air interfaces, and interface layout

The connecting cables include motor cables, data cables, and grounding conductors. The motor cable corresponds to controller side XD20.1/XD20.2 and mechanical arm side X30; The data cable corresponds to XF21 to X31; The grounding conductor is connected through M4 ring cable terminals with a standard torque of approximately 2.8 Nm. The grounding conductor is not within the standard supply range and can be ordered as an option, but must be connected by the customer to ensure a low resistance connection between the robotic arm and the control cabinet. The equipotential connection should be checked according to VDE 0100 and EN 60204-1.

When wiring, the bending radius of fixed motor cables should not be less than 55 mm, and the bending radius of data cables should not be less than 45 mm. Cables should avoid mechanical stress, and connectors should not be subjected to tension. The cable must be installed indoors, with a fixed installation temperature range of about -30 ° C to+80 ° C. The motor cable and data cable should be laid separately in metal cable trays and EMC measures should be taken. It is recommended to reserve at least 200mm of space behind the A1 interface.

In terms of air interface, KR 6 provides AIR1, AIR2, AIR3, and AIR4; KR 13 provides AIR1, AIR2, and AIR3. The maximum pressure is 0.7 MPa (7 bar), and the vacuum is atmospheric pressure minus 0.095 MPa (0.95 bar). AIR0 can be used for continuous air extraction in HO models, forming a negative pressure environment with good sealing to reduce dust leakage. The recommended air flow rate is about 70 L/min, with an outer diameter of Ø 12 mm and an inner diameter of Ø 8 mm. If the suction is insufficient or the seal is damaged, insufficient negative pressure can lead to a decrease in cleaning performance or even failure.

The A1 interface is located behind the base and includes user connector X40, Ethernet X74, MEMD X32, data cable X31, motor cable X30, grounding M4 stud, additional shaft XP5.1, and air interface. The A2 interface is located on the arm and includes a motor indicator light, user connector X41, Ethernet X94, air interface, and brake release button. The A2 interface of KR 13 also includes X94 and X41. Correctly identifying interfaces can reduce wiring errors.

Transportation and Handling

The robot must be placed in the transport position before transportation. The transportation positions of KR 6 are A1 0 °, A2-140 °, A3 0 mm, A4 0 °; KR 13 is A1-90 °, A2-90 °, A3-100 mm, A4 0 °. Vibration and impact must be avoided during transportation, and the robot should maintain its transportation position until it is fixed.

KR 6 can be carried by two people and must be properly secured, slowly moved, and equipped with protective gear. KR 13 recommends using forklifts or lifting equipment. Three transport devices, three M10 rotating lifting rings, transport connecting plates, lifting ropes with sufficient load-bearing capacity, and a crane are required for lifting. The length of the sling should be greater than 1000 mm. The transportation device should be installed using M6x25-12.9 screws with a torque of 9.5 Nm; M5x25-12.9 screws with a torque of 5.6 Nm; M10 lifting rings with a torque of 45 Nm. Do not stand under the robotic arm.

Startup and Debugging

Before starting, it should be confirmed that the robot has been correctly installed, all safety equipment is available, the power supply voltage is consistent with the nameplate, the grounding and equipotential connections are correct, and the connecting cables are locked. If there is a significant difference between the internal temperature of the controller and the ambient temperature, wait for temperature equilibrium to avoid condensation. The default password for system software must be changed before startup and only authorized personnel should be informed.

The usual debugging sequence is: installing the base; Install the robotic arm; Connect ground wires, air ducts, motor cables, and data cables; Check the equipotential; Installation tools; Start the system according to the controller operation instructions; Test run in T1 mode. When starting or restarting for the first time, all safety circuit functions should be checked to confirm that there is no damage, foreign objects, or loose parts. If the startup is incomplete, temporary alternative measures must be taken, such as safety fences, warning signs, main switch locking, etc.

Manual movement and brake release

The brake release button on the A2 interface can be used for axis 1 to axis 4. When the button is pressed, the four axis brakes are released, allowing for manual movement of the robotic arm; Release the button to restore the brake. When using, the load must be supported by hand to prevent it from falling off. Attention: Improper use of brake release while the robot is powered on or off may result in loss of mastering position and require recalibration.

For emergency movements after accidents or malfunctions, an optional brake release device can be used. The controller must be turned off and locked before operation. The steps are: unplug XD20.1 and XD20.2 from the controller; Insert the two connectors into the adapter box; Insert the adapter box X20 into the brake release device; Insert handheld device X1 into the brake release device; Select the axis to be released by selecting the switch; Press the handheld device button, release the brake, and the robotic arm can be manually moved. This operation is only for exceptional and emergency situations, such as rescue personnel. Do not stand below the motion axis during operation.

Maintenance plan and lubrication

Maintenance work can only be carried out according to the document description, and any work beyond the scope should be completed by KUKA training personnel. Before maintenance, power should be cut off, locked, and tagged, and emergency stop devices should be kept effective. If it is necessary to work with electricity, it can only be carried out in T1 mode and additional safety measures should be taken. After the controller is powered off, some components may still carry a voltage of 50 V to 780 V for several minutes and must wait for discharge. ESD regulations must be followed.

KR 6 maintenance plan: Check the tightening torque of the four screws on the installation base for 100 hours, only to be executed after the first start-up or re commissioning; Lubricate the A3/A4 spline shaft for 1500 hours using Kl ü bersynth UH1 14-151, approximately 5 g; replace the bellows for 4000 hours or at least annually, and visually inspect for wear and cracks. This task must be completed by authorized personnel from KUKA.

KR 13 maintenance plan: 100 hour inspection of 4 screws on the base; 1500 hours of lubrication for A3/A4 spline shaft, approximately 10g; 4000 hours or at least annual replacement of bellows, A3/A4 toothed belt, lubricating cable assembly, using Kl ü berfood NH1 34-401, approximately 20g; 20000 hours or at least every 5 years to replace A1 gearbox lubricant, using Cassida Fluid GL150, initial filling amount of approximately 0.31 L; annual inspection of base screws. The replacement of toothed belts and corrugated pipes must be completed by authorized personnel.

After maintenance, functional testing must be conducted to confirm that all safety functions are functioning properly. If the security function is disabled during maintenance, it must be restored immediately after the work is completed.

Common faults and troubleshooting ideas

The faults of KUKA KR SCARA HO are often related to safety circuits, connecting cables, load data, brake release, negative air pressure, and maintenance deficiencies. The following are common problems and solutions for engineering sites.

Possible causes and suggestions for handling the phenomenon

Robot unable to enable or move safety door, enabling device, T1/T2 mode, emergency stop circuit abnormality check safety circuit, confirm correct mode, test enabling device and emergency stop function

Error in connection of motor cable, data cable, and grounding conductor during startup. Check XD20.1/XD20.2, X30, XF21, X31 to confirm locking

Abnormal positioning or large vibration load data not input, load center of gravity too large, inertia moment exceeding limit. Input correct load data into the controller and check the load diagram

Motor overheating, high ambient temperature, high duty cycle, excessive load, frequent emergency stops. Check the ambient temperature, reduce the load or duty cycle, and confirm that the motor temperature does not exceed 95 ° C

After releasing the brake, the position is lost. If the brake release button or device is not recalibrated and the master is not executed again, check the zero point

Insufficient negative air pressure, AIR0 insufficient suction, damaged seal, pipeline leakage. Check the flow rate of about 70 L/min and inspect the seal and pipeline

The corrugated pipe has cracked and reached the replacement cycle. If the environment wears out, it should be replaced after 4000 hours or every year. Authorized personnel should operate it

KR 13 abnormal toothed belt reaches the replacement cycle, with a load impact of 4000 hours or annual replacement of A3/A4 toothed belt

Stop running immediately if there is an error in the collision or collision mechanical limit program, interference, or insufficient safety distance. Contact KUKA for inspection before putting it back into use

The temperature difference between the internal condensation temperature of the controller and the environment is large. Wait for temperature balance to avoid immediate start-up

After the security function was modified abnormally, all new programs were not tested or modified programs were tested under T1 first

External device interference EMC wiring is not standardized, motor cables and data cables are separated in metal cable trays, and shielding and grounding are checked

If a robot collides or impacts with external forces, even if there is no obvious damage to its appearance, there may still be invisible damage, such as gradual loss of motor power transmission. Dents, paint wear, motors, and balance systems must be inspected, and damaged components must be replaced.

End flange installation

KR 6-end flange is used for connecting tools. During installation, align the end flange hole with the spindle hole and place it on the spindle end; Insert A3A4 zero point positioning pin; Rotate the positioning pin until it cannot rotate; Insert 2 M4x12-12.9 screws; Adjust the position of the end flange to insert the positioning pin into the spindle hole; Tighten the M4 screws diagonally to 2 Nm; remove the locating pin; Tighten diagonally to 4.4 Nm. Finally, test run in T1 mode and observe any abnormalities.

KR 13 end flange is installed on the spline end of the ball screw. The steps are similar: align the end flange hole with the ball screw flower key hole; Insert positioning pin; Insert 2 M5x16-12.9 screws; Adjust the position to insert the positioning pin into the hole; Tighten diagonally to 4.5 Nm; remove the locating pin; Tighten to 9 Nm again. Test in T1 mode after completion.

Retirement, storage, and disposal

When retiring, first release and unplug all peripheral connections, unplug motor cables, data cables, and grounding conductors, remove screws and washers, carefully lift the robotic arm and transport it away. If the robot gets stuck on the installation surface, the fastening materials and adhesives should be thoroughly removed to avoid sudden detachment and injury.

Before storage, tools and equipment should be removed, the robot should be cleaned and dried, checked for foreign objects and corrosion, all cover plates should be installed and sealed, electrical connections and hose connections should be sealed, covered with plastic cloth and sealed at the base to prevent dust, and desiccants should be placed if necessary. The storage environment should be dry, dust-free, avoid temperature fluctuations, avoid direct sunlight, and maintain an allowable temperature range. When discarded, classify by material: aluminum base, arm, connecting rod; Copper cable; Steel gearbox, ball screw splines, screws; Electronic components, motors, plastics, rubber, polyurethane, cable sheaths, etc. should be treated according to regulations. Lubricating grease and adhesives should refer to the latest safety data sheet.