LEAP Hand v2 Advanced

Upstream step marks a step taken from the linked guide.

1. 1

   Buy the parts

   Order the motors and parts on the parts page: 6 XM430-W210-T, 6 XM430-W350-T and 5 XC330-T288-T Dynamixels, two HN12-I101 sets, an FPX330-H101 set for its TAP screws, a U2D2 with a power hub, 180 mm cables, 100 lb fishing line for the tendons, M3 screws and inserts, 6701-2RS bearings, grease, threadlocker 271, PLA, dissolvable support, Filaflex Foamy TPU and a 12 V 20 A supply.

   Upstream stepv2-adv.leaphand.com/parts
2. 2

   Print or order the parts

   Have the palm, gear and MCP parts 3D printed in aluminum (the CAD page recommends PCBWay, about 1000 USD) or print the PLA versions. Print the fingers and upper palms in Filaflex Foamy TPU and PLA on a dual-nozzle Snapmaker J1S with a 0.2 mm nozzle for the PLA, from the provided 3MF projects, and the remaining PLA parts on any printer.

   Upstream stepv2-adv.leaphand.com/leap_cad
3. 3

   Build the MCP holders

   Press a bearing into each MCP holder inner and outer, pair them, fit an MCP forward between the bearings with an axle gear on the axle so the gears mesh and the tendon hole lines up with the holder's tendon channel, and fix each with an M2.5 20 mm bolt. Make three of one orientation and two mirrored, then fix them into the four-finger and thumb lower palms with two 20 mm bolts and two M2 6 mm screws each.

   Upstream stepv2-adv.leaphand.com/assembly
4. 4

   Fit the MCP motors and gears

   Fasten a horn gear to each of the five XM430-W210-T motors with M2.5 10 mm screws (three normal, two mirrored). Replace one corner screw of each motor (toward the front of the hand for index and pinky, toward the back for middle and ring) with a screw bushing and screw gear, greased between them, and tighten it hard with an M2.5 22 mm screw and red Loctite, then fix the motors to the lower palms.

   Upstream stepv2-adv.leaphand.com/assembly
5. 5

   Break in the MCP gears

   Check that the four M2 screws of each MCP forward assembly are tight and the motors are fastened securely. Connect one of the MCP motors to a 12V power source, a U2D2, and the Dynamixel Wizard software on your computer, scan for the motor and switch it to current control mode. Turn the torque on and move the MCP module forward and backward using the current control slider (if it does not move, push with your hands in the direction the motor pushes) until the motor and joint spin more smoothly. Repeat for the other four motors.

   Upstream stepv2-adv.leaphand.com/assembly
6. 6

   Fit the tendon motors

   Fit the horns and pulleys on the five XM430-W350-T motors with a roughly 60 cm double-knotted fishing-line tendon in each pulley. Push each tendon through the bottom hole of its MCP forward and into the MCP holder's tendon channel, fix the motors to the lower palm, and slide the four-fingers bottom over the middle and ring finger motors without pinching any tendon.

   Upstream stepv2-adv.leaphand.com/assembly
7. 7

   Fit the MCP side motors and fingers

   With each XC330-T288-T horn in its home position, insert the motors into the five MCP forwards with the M2 4 mm TAP screws, add the MCP spacers with M2.6 6 mm TAP screws and plug a long cable into each. Thread each tendon through the center channel of its finger, double-knot it, push the finger firmly onto its motor and fix it with four M2 8 mm TAP screws.

   Upstream stepv2-adv.leaphand.com/assembly
8. 8

   Join the palm and mount the hand

   Press an HN12-I101 onto the palm XM430-W350-T and XM430-W210-T, join the three lower palms through them, slot on the three upper palms with M3 6 mm screws, fit the U2D2 under its cover on brass inserts, and mount the hand to the arm through the four-fingers bottom mount with M3 screws to the hand and M6 screws to the arm.

   Upstream stepv2-adv.leaphand.com/assembly
9. 9

   Set IDs and wire the bus

   Program the motor IDs as for LEAP Hand v1: index 0 to 2, middle 3 to 5, ring 6 to 8, pinky 9 to 11, thumb 12 to 14, palm thumb 15 and palm four fingers 16. Chain the bus from a central eight-way power splitter with the MCP side and palm motors as the end points, and zip-tie the MCP side cables to the front of the fingers, in front of the logo bar: the guide warns that MCP side cables pulled out or caught in the gears as the MCP moves can damage the motors.

   Upstream stepv2-adv.leaphand.com/assembly
10. 10

    Power on and tension the tendons

    When powering on the hand for the first time and running the tensioning script, make sure the tendons sit in the pulley grooves: index and pinky wrap toward the front of the hand, middle and ring toward the back. The LEAP Hand v2 Advanced API covers the software.

    Upstream stepv2-adv.leaphand.com/assembly

Wiring, power and firmware are safety-relevant and shown for reference only. Check them against the source before building.