> ## Documentation Index
> Fetch the complete documentation index at: https://docs.wuji.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Mechanical Integration

This page covers mounting interfaces, soft-pad removal, handedness differences, and load and cable limits for Wuji Hand 2.

Wuji Hand 2 mounts to an arm or fixture through the wrist flange or the palm interface, and the mounting dimensions, handedness differences, and load and cable limits together set what a workable mounting design looks like.

## Wrist Mounting Interface

The wrist ships with a standard flange, plus an adapter mount and adapter flange in the box (see [package contents](https://docs.wuji.tech/docs/en/wuji-hand/latest/overview.md#package-contents)). These parts cover desktop fixturing and common flange mating out of the box.

## Palm Mounting Interface

The bottom of the palm provides a standard mounting interface for machining an arm-side adapter plate. The interface is the same on the left and right hands, and identical on 2.1 and 2.2:

| Item | Specification |
| - | - |
| Threaded hole 1 | M3×0.5 fine thread 6H, thread depth over 5.5 mm, ⌀4 (0/+0.05) counterbore 2.35 ± 0.03 deep |
| Threaded holes 2 and 3 | M4×0.5 fine thread 6H, thread depth over 4 mm, ⌀7 (0/+0.06) counterbore 1 mm deep |
| Datum references | Located by datum dimensions 28.00 (0/−0.05) and 5.15 (+0.15/−0.05) |

The STEP assembly of the palm mounting interface (palm shell and harness) and a single-page A3 dimensioned drawing ship with the [wuji-description repository](https://github.com/wuji-technology/wuji-description). For how to get them, see [Palm Interface STEP and Drawings](#palm-interface-step-and-drawings).

## Remove and Refit the Soft Pad

Power the device down before you remove or refit the soft pad:

1. Remove the Phillips screws at the palm and thumb web.
2. Lay the hand flat and push the thumb upward until all five fingers come together.
3. Push the palm plastic outward until the palm soft pad lifts and exposes the adapter-mount screws.
4. Remove the adapter-mount screws for disassembly. To refit the soft pad, press the palm plastic back into place, then tighten the two screws at the palm and thumb web.

## Left and Right Hand Differences

The left and right hands are mirrored parts, and the model meshes are symmetric. Factory default IPs differ by handedness (see [Network Configuration](https://docs.wuji.tech/docs/en/wuji-hand/latest/electrical-network-integration.md#network-configuration)).

## Load and Cable Limits

> [!WARNING]
>
> The integration limits below aren't available yet and will be added later: permitted wrist load, bending moment and shock limits, minimum cable bend radius and exit direction, motion clearance, and mounting screw specifications with recommended torque. Confirm the limits with support before you finalize an integration design.

* Assess wrist load, bending moment, and shock for the actual application. Avoid high loads and shock until you confirm the limits.
* Leave room for the cable bend radius, exit direction, and motion clearance required by your integration.
* Always run the hand with the soft pad and skin fitted. The exposed flex cables on the finger surface are fragile, so work on them only briefly during maintenance and protect them from scratches (see [User Notice](https://docs.wuji.tech/docs/en/wuji-hand/latest/user-notice.md#cable-and-flex-cable-protection))
* For the safety boundary when running with a robot arm, see [Maintenance](https://docs.wuji.tech/docs/en/wuji-hand/latest/maintenance.md#safety-responsibilities-when-running-with-a-robot-arm)

## Palm Interface STEP and Drawings

The palm mounting interface STEP and A3 dimensioned drawing ship with the wuji-description repository. For the Beta full-hand STEP assemblies, use [wuji-description v2026.9.11](https://github.com/wuji-technology/wuji-description/tree/v2026.9.11).

| Resource | Path and use |
| - | - |
| Palm mounting interface STEP | `hand2/hand2_2/attachment/wuji-hand2-description-{left,right}-mount_hand2_2_step.STEP`, the palm shell and wire harness only, for machining a custom arm-side adapter or fixture |
| A3 dimensioned drawing | `hand2/hand2_2/attachment/wuji-hand2-description-{left,right}-mount_hand2_2.pdf`, dimensioning the threaded holes a custom adapter bolts into. Specs are in [Palm Mounting Interface](#palm-mounting-interface) |

Left and right files mirror each other. The palm mounting interface files are identical between 2.2 and 2.1 — the version marker in each filename only aligns with its directory, since the palm mounting interface didn't change between revisions. `attachment/` sits outside the ROS 2 package root at `body/`, so colcon doesn't install it.

## Related Integration Guides

* [Model Assets and Loading](https://docs.wuji.tech/docs/en/wuji-hand/latest/model-integration.md)

- [Electrical and Network Integration](https://docs.wuji.tech/docs/en/wuji-hand/latest/electrical-network-integration.md)


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