Follower arm · Step 2 of 26 · F-002

Set motor IDs 1–6 and baud rate before assembly

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Set IDs now: "it will be troublesome to disassemble and assemble the servo cable after assembly" (Waveshare).

Waveshare board: both jumpers on the B (USB) channel (LeRobot).

Supply voltage follows the motor variant, never a single value: 5V for the standard 7.4V STS3215; 12V 5A+ only if the optional 12V follower motors are fitted (README, D-002).

Connect one motor at a time to the
control board
Control board. The small circuit board (a Waveshare bus servo adapter) that connects to your computer by USB and to motor 1 by a 3-pin cable. It powers and talks to all six motors through the chain and sits on a printed plate on the base.Source: lerobot/docs/source/so101.mdx#2-set-the-motors-ids-and-baudrates · waveshare.com
and run the LeRobot setup-motors command for this arm.
src
- instructions — Connect one motor at a time to the board and run the LeRobot setup-motors command for this arm; the script names the joint and writes the ID. Software setup itself is out of scope here.
The script names the joint and writes the
ID
Motor ID. The number 1 to 6 written into each motor before building, so the control board can tell the motors apart on one cable chain. 1 is the motor in the base, 6 is the gripper.Source: lerobot/docs/source/so101.mdx#2-set-the-motors-ids-and-baudrates
into the motor: 1 is the motor in the base, 6 is the gripper.
src
- instructions — Connect one motor at a time to the board and run the LeRobot setup-motors command for this arm; the script names the joint and writes the ID. Software setup itself is out of scope here.
- check — Each motor answers on its own ID 1–6, bottom joint = 1, gripper = 6; leader and follower motors are labelled and kept apart.
Write the number on each motor, and keep the leader and follower motors apart.
src
- check — Each motor answers on its own ID 1–6, bottom joint = 1, gripper = 6; leader and follower motors are labelled and kept apart.
- wiki.seeedstudio.com — "label them and write on each motor"
Do this before building: the cable is hard to reach once the arm is assembled.
src
- warnings — Set IDs now: "it will be troublesome to disassemble and assemble the servo cable after assembly" (Waveshare). · Waveshare board: both jumpers on the B (USB) channel (LeRobot). · Supply voltage follows the motor variant, never a single value: 5V for the standard 7.4V STS3215; 12V 5A+ only if the optional 12V follower motors are fitted (README, D-002).

Done when Each motor answers on its own number, 1 to 6, and every motor is labelled.

waveshare.comServo Preprocessing: set IDs before assembling

wiki.seeedstudio.com"label them and write on each motor"

wiki.seeedstudio.com"check your motor model, gear ratio, and power supply voltage again"

SO-ARM100/README.md#sourcing-partsIMPORTANT note on 7.4V vs 12V servos and supplies

Notes: Connect one motor at a time to the board and run the LeRobot setup-motors command for this arm; the script names the joint and writes the ID. Software setup itself is out of scope here.

Check: Each motor answers on its own ID 1–6, bottom joint = 1, gripper = 6; leader and follower motors are labelled and kept apart.

You need

STS3215 motor, 1:345 gear, code C001Feetech STS3215 servo, 7.4V, 1:345 gear (C001) servo-sts3215-c001-345
approximation3D stand-in
Stand-in shape: the 3D geometry or placement is not measured from the real part.
Qty 7 is the two-arm build (6 follower + 1 leader). A 12V variant with 30 kg.cm stall exists for the follower only and needs a 12V 5A+ supply (README). Includes two horns and a 3-pin cable per the assembly texts; kit contents are not itemised upstream. Geometry: the upstream repo's own simplified body `STEP/SO100/STS3215_03a.step` (Apache-2.0, single solid drawn to the datasheet, D-007 for where they differ) with its fused horn plates cut off and the datasheet ø6 x 3.4 output boss added, posed on the embedded vendor model's transform; the vendor mesh is not redistributed.
details
Control boardMotor control board (Waveshare bus servo adapter) motor-control-board
approximation3D stand-in
Stand-in shape: the 3D geometry or placement is not measured from the real part.
One per arm. Set both jumpers to the B (USB) channel before configuring motors (LeRobot troubleshooting). Geometry: the assembly STEP embeds a vendor PCB model of unknown provenance; the pipeline exports a bounding-box primitive instead (approximation).
details
USB-C cableUSB-C cable usb-c-cable details
5V power supply (for the standard 7.4V motors)Power supply, 5V (for 7.4V servos) power-supply-5v details
3-pin motor cable3-pin servo bus cable servo-cable-3pin
unverifiedno source yet
Not checked yet: no public source confirms this. Treat it as a best guess and report what you find.
Used to daisy-chain motors and reach the controller board. Not itemised in the README BOM; the assembly texts assume they come with the servos. Qty 6 per arm = the six cable bodies (Component1–4, 6, 7) plus two 050375033 connector housings modelled in SO101 Assembly.step; kit-shipped count still unsourced.
details

Sources (5)

lerobot/docs/source/so101.mdx#2-set-the-motors-ids-and-baudrates
waveshare.com (retrieved 2026-09-07) — Servo Preprocessing: set IDs before assembling
wiki.seeedstudio.com (retrieved 2026-09-07) — "label them and write on each motor"
wiki.seeedstudio.com (retrieved 2026-09-07) — "check your motor model, gear ratio, and power supply voltage again"
SO-ARM100/README.md#sourcing-parts — IMPORTANT note on 7.4V vs 12V servos and supplies