# Step 11: Install the Linkage Shaft

> Assemble the D-shaft linkage and mount it between parts 600_36A, 600_39C, and 600_37C to build the foot.

- Page: https://docs.menlo.ai/asimov/1/build/assembly-steps/left-leg-module/foot-assembly/step-11
- Section: Asimov › Asimov 1 › Assemble Asimov 1 › Assemble › Left Leg Module › Foot Assembly
- Previous: [Step 10: Install the Linkage Cranks and Cover](https://docs.menlo.ai/asimov/1/build/assembly-steps/left-leg-module/knee-and-calf-assembly/step-10.md)
- Next: [Step 12: Assemble the Foot Pivot](https://docs.menlo.ai/asimov/1/build/assembly-steps/left-leg-module/foot-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 |
| - | -: |
| `600_36A` | 1 |
| `600_39C` | 1 |
| `600_37C` | 1 |
| 6mm D-Shaft Stainless Steel (part `600_31X`) | 1 |
| 6mm Bore 1-Side, 2-Post Pillow Block | 2 |
| Ball Joint Rod End (part `600_19X`) | 2 |
| Steel Set-Screw Collar | 2 |
| M4x16 Flat bolt | 11 |
| Threadlocker | As needed |

## Instructions

1. Take the 6mm D-Shaft Stainless Steel and put **2 of** Steel Set-Screw Collars onto it. Move it to the middle of the D-Shaft. Slightly tighten each set screw to keep the collar in place.

2. Take **2 of** Ball Joint Rod Ends and put one each on the left and right of the D-Shaft.

3. Take **2 of** 6mm Bore 1-Side, 2-Post Pillow Blocks and put one each on the left and right of the D-shaft. Make sure that the bearing facing outward on the Pillow Block is sunken into the hole instead of flat against it. Please view the visualization in detail to install it correctly.

4. Take part `600_36A` and fit it onto part `600_39C` as shown below.

5. Then take the D-shaft component we have been building and align it with part `600_36A` and `600_39C` according to the visualization below.

6. Flip the assembly upside down so part `600_39C` is visible. Take **4 of** M4x16 Flat bolts and lightly tighten them into the holes on part `600_39C` to align with the threaded holes in the two pillow-block legs.

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** M4x16 Flat bolts one at a time,
   - apply threadlocker,
   - then tighten them back to secure Part `600_39C` and the 2 Pillow Block.

8. Take part `600_37C` and align it with the holes on part `600_36A` as shown below

9. Take **7 of** M4x16 Flat bolts and tighten them into the 7 holes on part `600_39C` as shown below to secure it to part `600_37C`.

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 **7 of** M4x16 Flat bolts one at a time,
    - apply threadlocker,
    - then tighten them back to secure Part `600_39C` and part `600_37C` together.

11. Turn the current subassembly around such that part `600_39C` is facing downward toward the floor. Push the 2 Ball Joint Rod Ends flush against the 2 Pillow Blocks, then tighten the set screw on each Steel Set-Screw Collar to secure them in place.