This guide describes how to replace the electronics harness and brackets in MiR Shelf Carrier 250. The electronics kit includes the safety relays and terminal blocks.

Things you'll need

• A MiR Shelf Carrier 250 electronics harness and brackets kit from MiR

• Screwdrivers with the following heads:

  • T45, T20, and T10

  • 7 mm hex socket

• Torque wrenches for the following:

  • 2.5 Nm with a T20 head and a 7 mm hex socket head

  • 15 Nm with a T45 head

• Cable ties

Before replacing the electronics bracket

Step 1: Turn off the robot and disconnect the battery. To disconnect the battery, follow these steps:

1. Remove the rear cover by pressing the two white buttons and pulling off the cover. When removing the cover, un-click the two bottom corners first and then the two top corners.
   
2. Turn the Battery lock switch clockwise to release the Battery lever.
   
3. Pull the Battery lever down to disconnect the battery.
   
4. Turn the Battery lock switch counter-clockwise to lock the battery lever again.

Step 2: Remove the top cover by unscrewing all 14 screws in the top cover using a T20 screwdriver.

Step 3: Remove the top compartment covers from the interface compartments by unscrewing the eight screws with a T10 screwdriver.

Step 4: Disconnect the GPIO, Safety-related functions, and Emergency stop connectors from the robot's top interfaces. These are the cables labeled 4-8.

Step 5: Remove the weights in the four corners by unscrewing the two screws in each set.

Step 6: Remove the weight brackets by unscrewing the large screws and the two nuts on each bracket. Use a T45 screwdriver for the large screws and a 7 mm hex socket screwdriver for the nuts.

Replacing the electronics bracket

Step 1: Cut the cable ties around the cables connected to the electronics bracket.

Step 2: Unscrew the four screws in the end switches.

Step 3: Demount the electronics bracket by unscrewing the two nuts behind it, and flip the bracket 90°. Use a 7 mm wrench to unscrew the nuts.

Step 4: Disconnect the wires that connect to the actuator. These are wires 3.1, 3.2, 3.3, and 3.4.

Step 5: Remove the electronics bracket and replace it with the new bracket.

Step 6: Connect the wires from the actuator cable back into the electronic bracket.

Step 7: Place the switches at each end of the lifting mechanism and loosely screw in the four bolts. While pulling the switches outwards (towards the Emergency stop buttons) tighten the screws. The switches must be placed as far out as possible to make sure they register the pins' positions correctly.

Step 8: Mount the new electronics bracket by screwing on the two nuts behind it. Tighten the nuts to 2.5 Nm.

Step 9: Replace all the cable ties removed in step 1.

Reassembling the robot

Step 1: Mount the weight brackets and weights back on the robot. Tighten the large screws to 15 Nm and the nuts to 2.5 Nm.

Step 2: Reconnect the top interface connectors, and mount the top compartment covers by screwing in the four screws in each cover with a T10 screwdriver. Do not tighten the screws too much, and make sure to pull the end of the antenna cable through the antenna hole.

Step 3: Mount the top cover back onto the robot. Start by screwing in the four center screws and then the 10 outer screws using a T20 screwdriver. Make sure to tighten all of the screws to 2.5 Nm.

Step 4: Reconnect the battery and turn on the robot. You have now finished replacing the actuator assembly.

Testing

Go to Setup > I/O modules and under MiR internal I/Os complete the following sequence and verify that the shelf carrier performs as expected:

1. Under Outputs, select 3. Verify that the carrier pins rise up.
   

2. Once the pins are raised, verify that 3 under Inputs is green.
   

3. Under Outputs, select 2. Verify that the carrier pins lower into the robot.
   

4. Once the pins are lowered, verify that 2 under Inputs is green.
   

If the pins were raised and lowered as expected and the correct input feedback was received, MiR Shelf Carrier 250 is correctly installed. If not, check the cables you connected to the top electrical interfaces.