# Step 12: Install and Connect the Wrist Actuator

> Attach part 300_10A to part 300_16C with threadlocked M4x10 Flat bolts, install actuator ID 22 with parts 300_11A and 300_12B and threadlocked M3x12 Flat bolts, then connect it to actuator ID 21.

- Page: https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/forearm-assembly/step-12
- Section: Asimov › Asimov 1 › Assemble Asimov 1 › Assemble › Right Arm Module › Forearm Assembly
- Previous: [Step 11: Attach the Elbow Shaft Plate and Actuator Housing](https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/forearm-assembly/step-11.md)
- Next: [Step 13: Connect the Shoulder and Elbow Assemblies](https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/upper-arm-and-forearm-connection/step-13.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 |
| - | -: |
| Assembly from Step 11 | 1 |
| `300_10A` | 1 |
| `300_11A` | 1 |
| `300_12B` | 1 |
| EC-A4310-P2-36 actuator (part `300_23X`) (ID 22) | 1 |
| M4x10 Flat bolt | 3 |
| M3x12 Flat bolt | 16 |
| Threadlocker | As needed |

## Instructions

1. Take assembly from Step 11 and flip it around such that part `300_08A` with the bearing is facing the ceiling. Take part `300_10A`, align the protrusion with the bearing on part `300_08A` and align the 3 holes on it with part `300_16C`.

2. Take **3 of** M4x10 Flat bolts and lightly tighten into the 3 holes on part `300_10A` to align with part `300_16C`. 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 **3 of** M4x10 Flat bolts one at a time,
   - apply threadlocker,
   - then tighten them back to secure Part `300_10A` and part `300_16C` together.

3. Take the EC-A4310-P2-36 actuator (ID 22), align the port with the port cut-out on part `300_16C`, then slot it into the hollow part.

4. Take part `300_11A` and align it 4 holes at 4 corners with the 4 threaded holes on part `300_16C`. Also, align the 6 holes inner holes on the part with the threaded holes on the actuator shell.

5. Take **10 of** M3x12 Flat bolts and lightly tighten into the 10 holes on part `300_11A` to align with `300_16C` and the actuator.

6. 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** M3x12 Flat bolts from the inner holes one at a time in a star formation,
   - apply threadlocker,
   - then tighten them back to secure Part `300_11A` and the actuator together.

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 **4 of** M3x12 Flat bolts from the corner holes one at a time in a star formation,
   - apply threadlocker,
   - then tighten them back to secure Part `300_11A` and part `300_16C` together.

8. Take part `300_12B` and align the 6 holes on it with the 6 threaded holes on the actuator shaft.

9. Take **6 of** M3x12 Flat bolts and lightly tighten into the 6 holes on part `300_12B` to align with the actuator.

10. 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** M3x12 Flat bolts one at a time in a star formation,
    - apply threadlocker,
    - then tighten them back to secure Part `300_12B` and the actuator together.

11. Connect the free connector of the double-ended XT30 (2+2) cable from the EC-A4310-P2-36 actuator (part `300_22X`) (ID 21) to the port on actuator (ID 22).