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Slide motor 2 in from the top and fasten Loading 3D view…
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Take the motor you labelled 2. src servos.yaml · follower/shoulder_lift — ID 2 · STS3215 1:345 · Feetech STS3215 servo, 7.4V, 1:345 gear (C001) F-002 · check — Each motor answers on its own ID 1–6, bottom joint = 1, gripper = 6; leader and follower motors are labelled and kept apart. Lower it into the shoulder motor holder you added in step 8, going in from the top. src lerobot/docs/source/so101.mdx#joint-2 — "Slide the second motor in from the top. Fasten the second motor with 4 M2x6mm screws." F-014 · check — Holder seated on the shoulder, ready to receive motor 2 from the top. orientation note — Inserted from the top (LeRobot). Fix it with 4 small self-tapping screws, Self-tapping screw. A screw that cuts its own thread into the plastic as you drive it. These are the smallest screws in the kit and hold each motor in its printed bracket. No public source confirms the exact size yet (D-001).Source: lerobot/docs/source/so101.mdx#joint-1 · waveshare.com src lerobot/docs/source/so101.mdx#joint-2 — "Slide the second motor in from the top. Fasten the second motor with 4 M2x6mm screws." check — Motor 2 held by 4 motor-tab screws, two per side, each side one into the shoulder and one into the holder; its cable connects to motor 1 (either port). instructions — The four screws are horizontal: on each side the lower one passes through the shoulder, the upper one through the shoulder motor holder, so they also lock the holder to the shoulder. Connect motor 2 to motor 1 with the 3-pin cable already on motor 2. Either of motor 1's two sockets Socket. Each motor has two identical 3-pin sockets. Cables run from motor to motor in a chain, so a cable can use either socket.Source: waveshare.com src check — Motor 2 held by 4 motor-tab screws, two per side, each side one into the shoulder and one into the holder; its cable connects to motor 1 (either port). waveshare.com — Follower step 5: connect servo 1 cable to servo 2, either port F-003 · title — Plug one 3-pin cable into each motor before building Done when Motor 2 is held by 4 screws and a cable runs from motor 2 to motor 1.
lerobot/docs/source/so101.mdx#joint-2 "Slide the second motor in from the top. Fasten the second motor with 4 M2x6mm screws." waveshare.com Follower step 5: connect servo 1 cable to servo 2, either port SO-ARM100/STEP/SO101/SO101 Assembly.step placement check (viewer/public/geometry/placements.json): servo 2 sits in Motor_holder_SO101_Base (42% enclosed), entered from above SO-ARM100/STEP/SO101/SO101 Assembly.step placement check (pipeline hole test): per side one screw through a Rotation_Pitch_SO101 hole and one through a Motor_holder_SO101_Base hole, all horizontal Orientation: Inserted from the top (LeRobot).
Notes: The four screws are horizontal: on each side the lower one passes through the shoulder, the upper one through the shoulder motor holder, so they also lock the holder to the shoulder.
Check: Motor 2 held by 4 motor-tab screws, two per side, each side one into the shoulder and one into the holder; its cable connects to motor 1 (either port).
Motor slot: shoulder_lift · ID 2 · STS3215 1:345 ·
7.4V servo on a 5V supply; 12V servo on a 12V 5A+ supply (optional variant);
How we placed it: Part role confirmed by placement in the upstream assembly STEP: servo 2 sits in Motor_holder_SO101_Base (42% enclosed), entered from above.
You need STS3215 motor, 1:345 gear, code C001 Feetech 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 Shoulder motor holder Motor holder (base side) motor-holder-so101-base details Small self-tapping screw (motor screw) Motor-tab screw, M2-class self-tapping motor-tab-screw unverifiedno source yet Not checked yet: no public source confirms this. Treat it as a best guess and report what you find.
Sources disagree and no kit has been measured (D-001, open). Upstream default = the assembly STEP, which models 24 positions per arm: 22 x "Type I Cross Recessed Fillister Head Tapping Screw ANSI B18.6.4 1-42 x 0.1875 Type AB" (≈ ø1.9 x 4.8 mm) and, for the two screws that enter motor 1 from above, 2 x "0-48 x 0.1875" (≈ ø1.5 x 4.8 mm). Vendor/doc variants: LeRobot "M2x6mm screws (smallest screws)"; Waveshare "pointed screws". The Feetech datasheet gives no tab screw and ships "No Accessories". Qty = count used across the LeRobot steps (24 + 21 positions); a kit inventory settles the spec and count. Seating per screw is read from the STEP by the pipeline (shank through a hole of which printed part) and drives what the 3D view shows at each step.
×4 details Phillips screwdriver #0 · PH0 tool details Phillips screwdriver #1 · PH1 tool details Cables in the 3D view motor 1 → motor 2 shoulder pan → shoulder lift cable-shoulder-pan-to-shoulder-lift approximation3D stand-in Stand-in shape: the 3D geometry or placement is not measured from the real part.
Sources (4) How we placed it Part role confirmed by placement in the upstream assembly STEP: servo 2 sits in Motor_holder_SO101_Base (42% enclosed), entered from above.