# Step 11: Attach the Elbow Shaft Plate and Actuator Housing

> Attach part 300_09A to the shaft of actuator ID 21 with six threadlocked M3x16 Flat bolts and attach part 300_16C with three threadlocked M4x10 Flat bolts.

- Page: https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/forearm-assembly/step-11
- Section: Asimov › Asimov 1 › Assemble Asimov 1 › Assemble › Right Arm Module › Forearm Assembly
- Previous: [Step 10: Attach the Elbow Housing Plates](https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/forearm-assembly/step-10.md)
- Next: [Step 12: Install and Connect the Wrist Actuator](https://docs.menlo.ai/asimov/1/build/assembly-steps/right-arm-module/forearm-assembly/step-12.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 10 | 1 |
| `300_09A` | 1 |
| `300_16C` | 1 |
| M3x16 Flat bolt | 6 |
| M4x10 Flat bolt | 3 |
| Threadlocker | As needed |

## Instructions

1. Take the assembly from Step 10 and lay it flat on a surface such that the actuator is facing upward toward the ceiling.

2. Take part `300_09A` and align the 6 holes on it with with the actuator shaft.

   > [!WARNING]
   >
   > **Make sure the groove match**
   >
   > Rotate the visualization below to see the underside of part `300_09A` to make sure the groove is oriented correctly.

3. Take **6 of** M3x16 Flat bolts and lightly tighten into the 6 holes on part `300_09A` to align with the actuator shaft.

4. Take part `300_16C` and rotate it such that the port cut out on it is facing toward you. Align the 3 holes on part `300_16C`  with the 3 holes on part `300_09A`.

5. Take **3 of** M4x10 Flat bolts and lightly tighten into the 3 holes on part `300_09A` to align with part `300_16C`.

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** M3x16 Flat bolts one at a time in a star formation,
   - apply threadlocker,
   - then tighten them back to secure Part `300_09A` 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 **3 of** M4x10 Flat bolts one at a time,
   - apply threadlocker,
   - then tighten them back to secure Part `300_09A` and part `300_16C` together.