# Step 8: Attach the Shoulder Yaw Joint Plate and Shaft Mount

> Secure part 300_05A to actuator ID 20 with eight threadlocked M3x12 Flat bolts, then route the cable through part 300_06B and secure it to the actuator shaft with six threadlocked M4x20 Socket bolts.

- Page: https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/shoulder-and-upper-arm-connection/step-8
- Section: Asimov › Asimov 1 › Assemble Asimov 1 › Assemble › Right Arm Module › Shoulder + Upper Arm Connection
- Previous: [Step 7: Connect and Join the Shoulder Assemblies](https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/shoulder-and-upper-arm-connection/step-7.md)
- Next: [Step 9: Install the Elbow Actuator and Route Its Cables](https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/forearm-assembly/step-9.md)

> [!IMPORTANT]
> **Assign actuator IDs before assembly**
>
> Assign and verify all 25 actuator IDs before assembling the robot. The robot will not work correctly with missing or incorrect IDs. IDs must be assigned one actuator at a time on the bench; you may need to disassemble the robot if you skip this step. See [Assign Actuator IDs](https://docs.menlo.ai/asimov/1/build/assembly-preparations/assign-actuator-ids.md).

## Parts needed

| Part | Count |
| - | -: |
| Current shoulder assembly from Step 7 | 1 |
| `300_05A` | 1 |
| `300_06B` | 1 |
| M3x12 Flat bolt | 8 |
| M4x20 Socket bolt | 6 |
| Threadlocker | As needed |

## Instructions

1. Now move Upper Arm Assembly upward so that the shaft of the Right Shoulder Yaw EC-A3814-H14-107 actuator (part `300_20X`) (ID 20) is facing the ceiling.

2. Take part `300_05A` and align it with the holes on the surface of Upper Arm Assembly around the actuator shaft.  Make sure this is positioned correctly, else your arm will be locked wrongly.

   > [!WARNING]
   >
   > **Make sure the orientation match**
   >
   > Part `300_05A` has 1 protrusion on its edge, it is important that this protrusion is facing toward you and part `300_03A` like in the visualization.

3. Take **8 of** M3x12 Flat bolts and lightly tighten it into the 8 holes on Part `300_05A` to align with the threaded holes on the actuator.

4. After the parts are aligned:

   > [!NOTE]
   >
   > **Not ready to apply threadlocker?**
   >
   > You can assemble without threadlocker while you check the fit, alignment, and orientation. When you are confident, disassemble as needed, apply threadlocker to the bolts, and reassemble them following these instructions.

   - remove **8 of** M3x12 Flat bolts one at a time in a star formation,
   - apply threadlocker,
   - then tighten them back to secure Part `300_05A` and the actuator together.

5. Take Part `300_06B` and align the 6 holes on the part with the actuator shaft holes. Also route the cable form the hollow shaft of the actuator through the center of part `300_06B`.

6. Take **6 of** M4x20 Socket bolts and lightly tighten each one into the holes to align part `300_06B` with the actuator.

7. After the parts are aligned:

   > [!NOTE]
   >
   > **Not ready to apply threadlocker?**
   >
   > You can assemble without threadlocker while you check the fit, alignment, and orientation. When you are confident, disassemble as needed, apply threadlocker to the bolts, and reassemble them following these instructions.

   - remove **6 of** M4x20 Socket bolts one at a time in a star formation,
   - apply threadlocker,
   - then tighten them back to secure Part `300_06B` and the actuator together.