Robonine · SO-ARM102 leader + follower kit

SO-ARM102 — stiffer, faster and reaching further than SO-ARM101

A robot arm pair for teleoperation and model training. Parallel gripper, camera and LeRobot support.

$389 First batch starts shipping in late October 2026. Delivery priced at checkout · import duty estimated

Buy the kit Compare with SO-ARM101
The assembled SO-ARM102 follower arm in black PET-CF with its parallel gripper, next to coloured training cubes and a cylinder
  • 5 degrees of freedom + parallel gripper, leader–follower pair
  • About twice as stiff as SO-ARM101
  • 483 mm reach, 352° base rotation
  • LeRobot-compatible, open source
  • Ships unassembled, worldwide

SO-ARM102 against SO-ARM101, on the same bench

  • ≈2× stiffer frame
  • 67 % higher shoulder and elbow servo speed (no load)
  • 1.6× better horizontal accuracy
  • 60 % more base rotation
  • 34–50 % larger objects in the gripper
  • 10 dB quieter

See it

SO-ARM102 in twenty seconds

The printed lattice parts, the assembled arm, and the leader–follower pair at work. The lattice is what topology optimisation left: material only where the load goes.

What is new

Three key improvements

The same open SO-ARM idea — a leader you move by hand and a follower that repeats it — rebuilt where SO-ARM101 ran out of stiffness, speed and reach.

A parallel gripper

Parallel jaws hold objects securely without rolling them as the gripper closes.

A stiffer frame

A PET-CF frame designed to reduce flex under load.

Faster joints

Shoulder and elbow servos with 67% higher no-load speed at 12 V.

Compared

SO-ARM102 and SO-ARM101, row by row

Measured on our bench with the same rig for both arms. Where a number is the servo maker’s rating or a calculation, the row says so.

SO-ARM101 SO-ARM102
Base rotation 220° 352°
Shoulder lift range 200° 224°
Elbow flex range 194° 243°
Wrist flex / wrist roll range 190° / 320° 196° / 328°
Horizontal reach 441 mm 483 mm
Reach behind the base 377 mm 473 mm
Tip deflection, 300 g on the gripper Arm fully extended, printed servo dummies — the frame alone 7.5 mm 3.9 mm
Shoulder and elbow speed Servo maker’s no-load rating at 12 V 45 rpm 75 rpm
Estimated horizontal accuracy From the measured base backlash at full reach ±2.96 mm ±1.85 mm
Noise at 1 m 70 dB 60 dB
Gripper One angular jaw Two parallel jaws, 0–85 mm
Largest box / cylinder / ball 56 / 48 / 40 mm 75 / 70 / 60 mm
Rated payload 150 g 300 g
Frame material PLA PET-CF
Dial gauge readings with 300 g at the gripper: 7.55 mm for SO-ARM101, 3.90 mm for SO-ARM102
Same rig, 300 g at the gripper: SO-ARM101 deflects 7.55 mm (left), SO-ARM102 3.90 mm (right). Both arms were built with printed servo dummies, so the frames are compared, not the motors.

SO-ARM101 stays on sale for classrooms that standardised on it.

Specification

What you are actually buying

Degrees of freedom 5 + parallel gripper
Configuration Leader–follower pair: the leader with a handle, the follower with the gripper
Reach 483 mm horizontal; about 500 mm arm length
Joint ranges Base 352° · shoulder 224° · elbow 243° · wrist flex 196° · wrist roll 328°
Rated payload 300 g
Repeatability About 0.1 mm, measured
Gripper Parallel, two moving jaws, 0–85 mm
Servos Follower: 2 × STS3235, 2 × STS3250, 2 × STS3215; leader: 6 × STS3215. Feetech TTL serial-bus servos with 12-bit magnetic encoders.
Frame PET-CF, topology-optimised; about 90 % of the parts are 3D printed
Power draw Follower at 12 V with 300 g: 1.3 A on average, 3.3 A at peak (measured)
Mounting Table mount 80 × 80 mm for M8 bolts, or C-clamps
Camera Included: OV2735 (USB UVC, 1920×1080, Full HD) USB camera, WSD-6006-V1.0 board, M12 2.8 mm lens; gripper mount with cable routing
Software Hugging Face LeRobot with the SO-ARM102 plugin · Robonine Lab in the browser · Python 3 · URDF for simulation
Openness Open source: CAD, printable parts and BOM

SO-ARM102 LeRobot setup guide

Two SO-ARM102 leader–follower pairs on a desk: a two-handed data-collection station

The hardware

In the box, and what you add

In the box

  • OV2735 (USB UVC, 1920×1080, Full HD) USB camera, WSD-6006-V1.0 board, M12 2.8 mm lens - included, as in SO-ARM101
  • Leader arm and follower arm — printed PET-CF parts, unassembled
  • Follower: 2 × STS3235, 2 × STS3250, 2 × STS3215; leader: 6 × STS3215. Feetech TTL serial-bus servos with 12-bit magnetic encoders.
  • Two Waveshare Bus Servo Adapters, one per arm; 12 V / 5 A follower power supply, 5 V / 2 A leader power supply, two USB-C data cables
  • Mounting hardware, fasteners, hex keys and spare screws
  • Cubes and cylinders for the pick-and-place exercises
  • Printed step-by-step assembly manual with a QR code into Robonine Lab

You add yourself

  • A computer with a USB port — Windows, macOS or Linux
  • An evening or two for assembly — the manual walks you through both arms

Ships unassembled in a foam-fitted box from our warehouse in China. Delivery cost and time for your country are shown at checkout before you pay.

Tested under load

Load test with a 300 g payload

The arm repeats the same movements while holding a 300 g load. A thermal camera monitors the servo temperatures: at a room temperature of 30 °C, the hottest servo stabilised at 46 °C. Current draw at 12 V averaged 1.3 A, peaking at 3.3 A.

Robonine Lab

Robonine Lab is included — free

Control the robot and record movements directly in your browser.

SO-ARM102 in a Robonine Lab teleoperation lesson

Open Robonine Lab

Price

One kit, one price

The full kit listed above. Assembly required.

What the price covers

  • Delivery priced at checkout from the warehouse's current rates
  • Import duty and VAT, where your country charges them: estimated at checkout, paid on delivery
  • Robonine Lab — every module and tool, at no extra charge
  • An unopened kit can be returned within 14 days for a full refund
  • Buying for a lab or a class? Add several to the cart, or ask us for an invoice
Ask for an invoice

Leader + follower

SO-ARM102 kit

$389

  • Delivery priced at checkout
Buy the kit

First batch starts shipping in late October 2026. Ships from our warehouse in China; the delivery time for your country is shown at checkout.

FAQ

Before you buy

Does it work with LeRobot?

Yes. Install the separate SO-ARM102 follower plugin and use the standard so101_leader type for the leader. The setup guide is linked in the specifications section.

How hard is the assembly?

The printed manual draws every step for both arms and the gripper, and the kit has the hex keys it needs. No soldering and no machining are involved.

What will I pay at the border?

Import duty and VAT are charged by your country’s customs, not by us. The checkout shows an estimate for your country before you pay, and the courier collects the actual amount on delivery.

How do delivery and returns work?

The kit ships from our warehouse in China. Delivery is priced from the warehouse's current rates and shown, with the delivery time, before you pay. An unopened kit can be returned within 14 days of receipt for a full refund.

How can I pay?

International bank cards — Visa, Mastercard and more. Payment happens on a secure payment page.

Buy or ask

Ask before you buy

Compatibility, a lab order, the platform — write and we will answer.

    Or write to us directly: hello@robonine.com