TECHNICAL REPAIR GUIDE

Mastering the IRB 6700 Wrist Replacement

A comprehensive step-by-step expert guide for qualified robotics technicians

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Target Audience

This guide is intended for trained and qualified robotics service personnel who possess the necessary mechanical and electrical skills and are familiar with ABB robot systems and safety procedures.

Overview

The wrist unit is a critical component of the ABB IRB 6700 robot arm, enabling complex movements and tool manipulation. Replacing it is a significant repair task requiring precision, the correct tools, and strict adherence to safety protocols. This guide breaks down the procedure detailed in the official product manual (section 4.5.2), offering insights for qualified technicians undertaking this replacement.

Industrial robot arm

The wrist unit (highlighted) of the ABB IRB 6700 robot. Image depicts approximate location, reference figure xx1300000597 in manual.

Core Value & Intent

While the official manual provides the definitive steps, this article aims to synthesize that information into a more accessible flow, highlighting critical points and potential challenges involved in the wrist replacement process to ensure a safe and successful repair.

Before beginning any work on the robot, ensure that you have thoroughly reviewed the official ABB documentation, including the safety guidelines in section 1.3.4. This guide supplements but does not replace the detailed procedures in the product manual.

Essential Prerequisites: Tools, Parts, and Consumables

Before commencing any work, meticulous preparation is crucial. Ensure you have the correct replacement wrist unit and all necessary tools and consumables as specified in the manual.

Spare Part

  • Wrist Unit: Verify the correct spare part number for your specific IRB 6700 variant using the Product manual, spare parts - IRB 6700.

Required Tools

  • Lifting: Roundsling (1 m, 1000 kg capacity), Overhead crane
  • Alignment: Guide Pins (M12x150, 3HAC13056-2, use in pairs)
  • Mechanical: Standard ABB Robotics Toolkit, Torque Wrench
  • Electrical: 24 VDC Power Supply (for brake release)
  • Calibration: Calibration Pendulum Toolkit (3HAC15716-1)
  • Miscellaneous: Pallet & Cardboard (for safe placement)

Consumables

  • Cable Ties: For securing harnesses
  • Grease: 3HAB3537-1 (for o-rings)
  • O-Ring: 3HAB3772-110 (for axis-5 motor cover)
  • Gasket: 3HAC033489-001 (for axis-6 motor cover)

Always double-check part numbers against the official spare parts list for your specific robot configuration and revision.

The Removal Process: A Methodical Approach

Removing the wrist involves careful disassembly and handling to prevent damage to the robot or injury to personnel. Follow these steps precisely in the given order.

1

Preparation

  • Clear Equipment: Remove any tools or equipment fitted to the turning disk/wrist.
  • Handle DressPack (If Applicable):
    • Remove the complete ball joint housing from the wrist cover bracket.
    • Remove the bracket itself to access wrist cover screws.
    • Remove the DressPack axis-6 cable support if installed.
  • Position the Robot: Jog the robot to the specified safe position:
    Axis 1:

    No significance

    Axis 2:

    -60°

    Axis 3:

    +60°

    Axis 4:

    +90°

    Axis 5:

    +90° (Critical)

    Axis 6:

    No significance

  • SAFETY FIRST:

    DANGER

    Perform a full safety shutdown. Turn off all electric power, hydraulic pressure, and air pressure supplies before entering the robot's working area.

  • Prepare Landing Zone: Set up a pallet with protective cardboard near the robot to safely place the removed wrist unit.
2

Remove Turning Disk(s)

  • Standard Turning Disk: Unscrew the attachment screws securing the standard turning disk and carefully remove it (reference figure: xx1300000492 and xx1300000493).
  • Process Turning Disk (If Applicable): If a process turning disk (DressPack) is fitted, remove its attachment screws (xx1300000599) and the disk itself (xx1300000600).
3

Access Wrist Cabling

  • Position Axis 5: If not already at +90°, use the 24 VDC power supply (Connected to R2.MP5: +=pin 2, -=pin 5) to release the brake and manually move axis 5 to the +90° position. This is critical for access.
  • Remove Wrist Cover: Unscrew and remove the wrist cover (xx1300000486).
  • Remove Heat Shield: Cut cable straps securing the harness to the heat protection plate (xx1300000489). Gently pull the harness aside and remove the heat shield plate (xx1300000490), storing it safely.
4

Disconnect Motor Cables

IMPORTANT

Before disconnecting any cables, ensure all power is fully removed from the system. Double-check that the robot controller is powered off and the main power supply is disconnected.

Axis 6 Motor:

  • Ensure power is off.
  • Remove the motor cover screws and cover (xx1200001080).
  • Disconnect the motor power and resolver cables (xx1300000488).

Axis 5 Motor:

  • Ensure power is off.
  • Remove the motor cover screws/washers and cover (xx1200001135).
  • Disconnect the motor power and resolver cables (xx1200001066).
  • Carefully remove the cable gland cover (xx1300000656), noting its orientation and ensuring the gasket isn't damaged.
  • Gently pull the motor cables out through the gland opening.
5

Lift and Remove the Wrist

CRITICAL SAFETY WARNING

The wrist unit weighs approximately 110 kg. Improper lifting can cause serious injury or damage to equipment. Follow these instructions precisely and ensure all lifting equipment is properly rated.

  • Attach Lifting Sling:
    • CRITICAL: Attach the 1m roundsling exactly as shown in figure xx1300000673. Incorrect placement poses a significant risk of the wrist becoming unbalanced and causing damage or injury.
    • Do not sling around the axis-5 gearbox.
    • Ensure the sling is taut and supporting the wrist's weight (approx. 110 kg). Use an overhead crane or suitable lifting device.
  • Use Guide Pins: Remove two opposing M12 attachment screws from the wrist-arm interface and replace them with M12x150 guide pins (3HAC13056-2). Lightly grease the pins.
  • Remove Remaining Screws: Unscrew the rest of the wrist attachment screws (xx1300000748).
  • Extract Cables: Carefully pull the wrist slightly out onto the guide pins (xx1300000749). Gently pull the disconnected axis 5 and 6 motor cabling out of the wrist housing (xx1300000769), ensuring no snagging or damage.
  • Lift Away: Slide the wrist completely off the guide pins and carefully lower it onto the prepared pallet.

The Refitting Process: Precision is Key

Reinstalling the wrist requires careful alignment, connection, and securing of all components. The process essentially reverses the removal steps, with specific additional considerations.

1

Preparation

  • Clean Surfaces: Thoroughly clean all mating surfaces on the arm tube and the new/repaired wrist unit. Ensure surfaces are free of debris, old gasket material, or contaminants.
  • Install Guide Pins: Fit two M12x150 guide pins into opposing holes on the arm tube flange. Grease pins lightly to facilitate smooth wrist insertion.
2

Attach Lifting Gear & Position Wrist

  • Lift Safely: Attach the 1m roundsling to the wrist exactly as done during removal (figure xx1300000673). Lift the wrist (110 kg) using the overhead crane.
  • Position on Pins: Carefully guide the wrist onto the guide pins (xx1300000770), leaving a small gap initially.
  • Feed Cables: Gently feed the axis 5 and 6 motor cables back into the wrist housing, avoiding pinching or forcing.
  • Slide into Place: Slide the wrist fully onto the guide pins until it mates with the arm tube flange (xx1300000749).
3

Secure Wrist

  • Initial Screws: Fit the M12 attachment screws into the accessible holes and tighten lightly.
  • Remove Pins & Final Screws: Remove the guide pins and install the remaining M12 screws.
  • Torque Down: Tighten all attachment screws progressively and evenly to the specified torque: 115 Nm (xx1300000748).

    Use a cross-pattern sequence to ensure even pressure distribution.

  • Position Axis 5: If necessary, use the 24 VDC power supply (R2.MP5) to release the brake and manually position axis 5 to +90°.
4

Reconnect Motor Cables

Axis 5 Motor:

  • Feed cables through the gland opening (xx1300000738).
  • Refit the cable gland cover (xx1200001016), ensuring the gasket is intact and orientation is correct.
  • Reconnect power and resolver cables (xx1200001016). Check o-ring (3HAB3772-110), lubricate with grease (3HAB3537-1), and ensure it's seated correctly (xx1200001021).
  • Refit the motor cover (xx1200001013), excluding screws for the heat shield initially. Do not reuse self-threading screws; replace with standard M4 machine screws if applicable.

Axis 6 Motor:

  • Ensure axis 5 is at +90°.
  • Push the cable harness carefully into the wrist recess and up towards the axis-6 motor.
  • Push the cable carrier into position (xx1300000667) and secure it with its M4 screw (xx1300001113, xx1300000485). Ensure it's level.
  • Secure the cable bracket (xx1300000484).
  • Reconnect power and resolver cables (xx1300000488), placing the resolver cable under the motor cable.
  • Check the motor cover gasket (3HAC033489-001), replace if needed.
  • Refit the motor cover (xx1200001080, xx1200001095).

Finalize Connections & Covers:

  • Refit the heat protection plate (xx1300000490) using the remaining axis-5 motor cover screws.
  • Secure the harness to the heat protection plate with new cable ties (xx1300000489).
  • Ensure all motor covers are tightly sealed.
  • Disconnect the 24 VDC power supply if used.
5

Refit Turning Disk(s)

  • Clean Surfaces: Ensure mating surfaces are clean.
  • Standard Disk: Refit the turning disk and secure with M8x25 screws (Steel 12.9 Gleitmo 603) and washers (8.4x13x1.5). Tighten to 35 Nm (xx1300000492).
  • Process Disk (If Applicable): Refit the process turning disk (xx1300000600) and secure with its screws (xx1300000599).

Critical Considerations & Final Steps

Wrist Cover Refitting Technique

Refitting the main wrist cover requires care to avoid pinching cables (xx1300000772). Follow this specific technique:

  1. Hold the cover at an angle
  2. Catch any hanging cables
  3. Lift the cover while angled
  4. Position the upper part first
  5. Then secure all screws to 10 Nm

Pro Tip: Using a small piece of electrical tape to temporarily hold cables in place can help prevent pinching during cover installation.

Recalibration: MANDATORY

This step is mandatory. Replacing the wrist affects the robot's kinematic chain. Use the Calibration Pendulum toolkit (3HAC15716-1) and follow the procedures in the calibration manual to perform a full recalibration.

Failure to recalibrate will result in:

  • Inaccurate robot positioning
  • Potential collision risks
  • Production quality issues
  • Premature wear on robot components

Refer to Chapter 5 of the main manual for general calibration information.

DressPack Refitting

If applicable, refit the DressPack components in this order:

  1. Refit the DressPack bracket to the wrist cover
  2. Attach the ball joint housing to the bracket
  3. Reinstall the DressPack into the arm tube ball joint housing

Consult the IRB 6700 DressPack manual for detailed procedures specific to your DressPack configuration.

Final Safety Check

DANGER - First test run may cause injury or damage!

Before returning the robot to operation, perform a thorough test run according to the safety guidelines in the manual (section 1.3.4).

  • Ensure all tools and equipment have been removed from the robot and work area
  • Check that all covers are properly secured
  • Verify that all cables are properly routed and secured
  • Perform a manual rotation check of all axes before power-up
  • Start initial test movements at reduced speed (25% or less)

Complete Process Flowchart

                                                flowchart TD
                                                A[Start] --> B[Preparation]
                                                B --> C[Remove Turning Disk]
                                                C --> D[Access Wrist Cabling]
                                                D --> E[Disconnect Motor Cables]
                                                E --> F[Lift and Remove Wrist]
                                                F --> G[Prepare New Wrist]
                                                G --> H[Position Wrist on Guide Pins]
                                                H --> I[Secure Wrist]
                                                I --> J[Reconnect Motor Cables]
                                                J --> K[Refit Turning Disk]
                                                K --> L{Recalibration}
                                                L -- MANDATORY --> M[Perform Full Recalibration]
                                                M --> N[Final Safety Check]
                                                N --> O[Test Run at Reduced Speed]
                                                O --> P[Return to Operation]
                                                style L fill:#f84156,stroke:#c10c32,color:white
                                                style M fill:#f84156,stroke:#c10c32,color:white
                                                %% DANGER states
                                                style F fill:#f8d66a,stroke:#dc7b06
                                                style H fill:#f8d66a,stroke:#dc7b06
                                                %% Normal states
                                                style A fill:#0c94e9,stroke:#0074c7,color:white
                                                style P fill:#0c94e9,stroke:#0074c7,color:white

Troubleshooting Common Issues

Even when following the procedure precisely, technicians may encounter challenges during the wrist replacement process. Here are solutions to common issues.

Wrist Binding on Guide Pins

Symptom:

The wrist unit feels tight or jams when sliding on the guide pins during removal or refitting.

Cause:

Misalignment of the lifting accessory causing uneven force, slight burrs on the mating surfaces, or improperly seated/lubricated guide pins.

Solution:

  1. Stop applying force immediately.
  2. Re-check the lifting accessory balance – adjust chains/slings for a perfectly level lift/lower.
  3. Ensure guide pins are fully seated and lightly lubricated.
  4. Inspect mating surfaces on both the arm and wrist for any burrs or debris and clean/address as necessary.

IMPORTANT

Never force the wrist; use only gentle, steady pressure.

Difficulty Mating Motor Pinions

Symptom:

The motor (especially Axis 5 or 6 if removed/disturbed) doesn't seem to seat correctly, or resistance is felt before full engagement.

Cause:

Misalignment between the motor pinion and the gearbox input gear, often due to slight rotation of either component, or incorrect angle of motor insertion.

Solution:

  1. Use the rotation tool (e.g., 3HAC7887-1) while the brake is released (via 24VDC supply) to gently rotate the motor pinion back and forth by tiny increments while applying slight inward pressure on the motor.
  2. Ensure the motor is being inserted perfectly straight relative to the gearbox flange.
  3. Double-check that the correct motor is being installed if multiple were removed.

Cable Harness Routing Challenges

Symptom:

Difficulty feeding the axis 5/6 cables back into the wrist housing or through the arm tube; cables seem twisted or bunched up.

Cause:

Cables may have twisted during removal, incorrect feeding order, snagging on internal features.

Solution:

  • Patience is key. Feed cables one connector at a time if necessary.
  • Use smooth, non-abrasive tools (like a specialized cable pulling sock or even just careful hand guidance) if needed, but avoid pulling forcefully on connectors.
  • Check for internal obstructions.
  • If cables seem twisted relative to their exit point at the arm base, it may require careful manipulation further back along the harness path.
  • Temporarily taping connectors into a streamlined bundle can help.

Damaged Fasteners or Threads

Symptom:

Screws are difficult to remove, heads are stripped, or screws won't tighten correctly during reassembly.

Cause:

Previous over-torquing, cross-threading, corrosion, use of incorrect tools.

Solution:

  • Use high-quality hex bits/sockets to avoid stripping heads.
  • If a screw is resistant, ensure you're turning it the correct way (lefty-loosey).
  • Apply penetrating oil sparingly if corrosion is suspected (ensure compatibility with robot surfaces).
  • If threads in the casting are damaged, repair often requires specialized inserts (e.g., Helicoil) or continue potentially replacing the larger component – consult ABB documentation or support for approved repair methods.
  • Always replace damaged screws with the exact specified type and grade.

Conclusion

Replacing the wrist unit on an ABB IRB 6700 is a complex but manageable task for experienced technicians. Success hinges on careful preparation, adherence to the specified procedures, correct use of tools and lifting equipment, meticulous cable handling, and mandatory post-replacement recalibration. Always prioritize safety and consult the official ABB documentation for definitive guidance and part numbers specific to your robot.

Need Additional Assistance?

For technical support or further information about ABB IRB 6700 maintenance and repair, contact ABB technical support or refer to the complete ABB product manual suite.

Related Guides

IRB 6700 Cable Harness Replacement

Comprehensive guide for replacing and routing internal cable harnesses in the IRB 6700 robot.

Repair Guide: Replacing the Axis 5 Motor

Step-by-step procedure for safely replacing the axis 5 motor in your IRB 6700 robot.

Maximizing Precision: IRB 6700 Calibration Guide

Detailed instructions for calibrating your IRB 6700 to ensure maximum precision and operational uptime.