# Step 8: Assemble the Knee Housing

> Fit the thigh assembly from Step 7 into the knee housing and install both side plates.

- Page: https://docs.menlo.ai/asimov/1/build/assembly-steps/left-leg-module/knee-and-calf-assembly/step-8
- Section: Asimov › Asimov 1 › Assemble Asimov 1 › Assemble › Left Leg Module › Knee + Calf Assembly
- Previous: [Step 7: Attach the Actuator Hub](https://docs.menlo.ai/asimov/1/build/assembly-steps/left-leg-module/thigh-assembly/step-7.md)
- Next: [Step 9: Install Left Ankle A and B Actuators](https://docs.menlo.ai/asimov/1/build/assembly-steps/left-leg-module/knee-and-calf-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 |
| - | -: |
| Thigh assembly from Step 7 | 1 |
| `600_10C` | 1 |
| `600_08A` | 1 |
| `600_09A` | 1 |
| M3x10 Flat bolt | 18 |
| M3x18 Socket bolt | 6 |
| Threadlocker | As needed |

## Instructions

1. Take the thigh assembly from Step 7 and lay it flat on the surface such that the L-shape part `600_12A` is facing upward toward the ceiling.

2. Take part `600_10C` and oriented it such that the knee cap is on top of the L-shape piece of part `600_12A`.

3. Slot the thigh assembly into part `600_10C` such that the two actuator holes are aligned with the knee portion first to help us estimate how the part will fit together.

4. Turn the leg toward the right so we can see the part of the thigh assembly with the bearing on the actuator facing upward toward the ceiling. Take part `600_08A` and fit it on to the groove on part `600_10C`, such that the protrusion fits into the bearing and then all the holes on part `600_08A` align with the threaded insert on part `600_10C`.

5. Take **9 of** M3x10 Flat bolts and lightly tighten into all the holes on part `600_08A` to align it with part `600_10C`. 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 **9 of** M3x10 Flat bolts one at a time in a star formation,
   - apply threadlocker,
   - then tighten them back to secure Part `600_08A` and part `600_10C`.

6. Flip the current assembly 180 degrees to the other side such that part `600_08A` is now facing downward toward the surface. You should be able to see the actuator shaft facing toward the ceiling.

7. Take **2 of** M3x18 Socket bolts and lightly tighten into the threaded holes on the actuator shaft. Make sure that the bolts are on the opposite side of each other, use those bolts as the leverage to turn the actuator shaft so that the bolts is on a straight line with the rest of part `600_10C`. This makes it easier to align with part `600_09A` later on. Remove **2 of** M3x18 Socket bolts after you are done.

8. Align part `600_09A` with the actuator such that the 6 holes nearer to the center of part aligned with the threaded holes on the actuator.

9. Reuse **2 of** M3x18 Socket bolts removed earlier and add **4** more, for **6** total. Lightly tighten them into the 6 holes near the center of part `600_09A` to align the part with the actuator and the groove on part `600_10C`.

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** M3x18 Socket bolts one at a time in a star formation,
    - apply threadlocker,
    - then tighten them back to secure Part `600_09A` and the actuator together.

11. Take **9 of** M3x10 Flat bolts and lightly tighten into all the holes on part `600_09A` to align it with part `600_10C`. 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 **9 of** M3x10 Flat bolts one at a time in a star formation,
    - apply threadlocker,
    - then tighten them back to secure Part `600_09A` and part `600_10C`.