Hardware Integration

This page is organized in two parts, mechanical mounting and electrical and network setup, and covers the interfaces, specifications, and limits you need to mount Wuji Hand 2 on a robot arm or fixture and bring up its power and network.

Mechanical Integration

Wuji Hand 2 mounts to an arm or fixture through the wrist flange or the palm interface, and the mounting dimensions, model coordinate frames, 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). 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 Beta 1 and Beta 2:

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. For how to get them, see Models 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.

Coordinate Frames and Models

• Root link: the root link of the base-free model is {l,r}_wrist, consistent across URDF, MJCF, and USD
• Variant with mount: files with the _with_mount suffix use the arm flange mount {l,r}_mount (69 g) as the root link, keep the wrist shell as a separate body, and keep the wrist flange frame addressable
• Kinematic equivalence: once the fixed mounting offset is subtracted, fingertip poses agree between the two variants to within 0.006 mm
• Actuator naming: {l,r}_{THJ|FFJ|MFJ|RFJ|LFJ}{0-3}, with the anatomical naming map in the Joint Table

Use the URDF definition as the source of truth for the relationship between the wrist mounting frame and root link. The CAD assets include simplified left- and right-hand STEP models, detailed STEP models of the wrist and standard flange, and a PDF of the engineering requirements for the wrist and standard flange. The models in each format (URDF / MJCF / USD) and the CAD assets ship with the wuji-description repository. For how to get them, see Models and Drawings. Use the whole-hand STEP for envelope and mounting-interface design.

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 below).

Load and Cable Limits

• 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)
• For the safety boundary when running with a robot arm, see Troubleshooting, Recovery, and Maintenance

Electrical and Network Integration

The device runs on nominal 12 V DC power and an Ethernet link with a static IP, with fixed conventions for power sequencing, addressing several devices, and recovering from a lost connection.

Power Supply

Power-Up and Power-Down Sequence

• Power up: connect the XT30 at the device end first, then plug in the adapter. Connect once the status light goes from blue breathing (self-check) to white breathing (ready)
• Power down: stop motion, call disable(), confirm the device is at rest, disconnect power, then unplug the cables
• Hot swap: neither the communication cable nor the power cable supports hot swapping. After an accidental disconnect, follow Timeouts, Disconnection, and Reconnection below

Network Configuration

The device uses a static IP and doesn't support DHCP. Factory default addresses:

Set your computer's network adapter to a static IP on the same subnet (such as 192.168.1.100). For the full round-trip of changing a device IP (write to flash, reboot to apply, reconnect at the new address), see SDK Reference.

Multiple Devices and Clients

• When several hands share a subnet, connect by serial number (sn) or handedness (handedness). With multiple devices of the same handedness on the network, use sn, otherwise the call raises AmbiguousHandedness
• Multiple clients at once (Wuji Studio, a recording script, and your application all connected) is the default behavior (enable_bridge=True). To switch to exclusive single-client mode, see SDK Reference

Timeouts, Disconnection, and Reconnection

• Connection parameters: ConnectOptions(timeout_ms=1000, retry_count=3)
• Communication loss while enabled: the device stops the motors and reports a fault. It doesn't resume motion on its own once communication returns—call enable() again (firmware v2.1.0 and later)

To recover the connection:

1. Check both ends of the network cable and the network equipment, and confirm that the link to the host has recovered.
2. Subscribe to joint_diagnostics, read the active error codes, decode them with WujiHand2.describe_error(code), and remove the reported causes.
3. Call enable() again and confirm that the status light turns solid white.