Robonine · SO-ARM102 leader + follower kit
A leader–follower robot arm pair for teleoperation, imitation learning and robot-data collection: a parallel gripper, a PET-CF frame with a topology-optimised structure, STS3250 servos in the shoulder and elbow, and 352° of base rotation. It runs on Hugging Face LeRobot from day one.
$439 First batch starts shipping in late October 2026. Delivery priced at checkout · import duty estimated
See it
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
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.
Two jaws that stay parallel through the whole 85 mm stroke instead of rolling the object as they close. Boxes up to ≈75 mm, bottles and cans up to ≈70 mm, balls up to ≈60 mm.
PET-CF instead of PLA, and a structure shaped by topology optimisation. With 300 g hanging from the gripper the tip moves 3.9 mm, against 7.5 mm on SO-ARM101.
STS3250 servos in the shoulder and elbow: 75 rpm against 45. The follower reaches the leader’s pose 67 % faster and starts moving 2.1× sooner.
352° of base rotation instead of 220°, 243° at the elbow instead of 194°, and 483 mm of horizontal reach. The arm reaches 26 % further behind its base and 39 % further down.
The leader arm ends in a handle rather than a copy of the gripper, so hours of teleoperation and demonstration recording are less tiring for the hand.
A camera mount on the gripper with cable routing along the arm, a table mount or C-clamps, and two pairs side by side for two-handed tasks.
Compared
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 | 250 g | 300 g |
| Frame material | PLA | PET-CF |
SO-ARM101 stays on sale for classrooms that standardised on it.
Specification
| 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 | Feetech serial-bus servos with 12-bit magnetic encoders; STS3250 in the shoulder and elbow |
| 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 camera, WSD-6006-V1.0 board, M12 2.8 mm lens; gripper mount with cable routing |
| Software | Hugging Face LeRobot · Robonine Lab in the browser · Python 3 · URDF for simulation |
| Openness | Open source: CAD, printable parts and BOM |
The hardware
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.
Up close
A photo of the assembled arm for scale, two views of the kit design, and a page from the assembly manual.
Tested under load
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
The manual’s QR code opens Robonine Lab, a browser platform: assembly, calibration, teleoperation, pick-and-place, computer vision and a final project, with the tools you need along the way in the same window.
Price
Everything on this page is in the box.
Leader + follower
$439
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
A parallel gripper instead of the angular jaw, a stiffer PET-CF frame, faster STS3250 servos in the shoulder and elbow, and wider joint ranges — 352° at the base. On our bench that came to about half the deflection under load, 67 % faster shoulder and elbow, and 10 dB less noise.
Yes. SO-ARM102 runs on Hugging Face LeRobot, so the datasets, policies and tutorials written for SO-ARM101 work on it from day one.
Yes — the CAD, the printable parts and the bill of materials are published, the same way SO-ARM100 and SO-ARM101 are.
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.
Yes. The kit includes the same camera as SO-ARM101: OV2735, WSD-6006-V1.0 board, M12 2.8 mm lens. The gripper has a camera mount and cable routing. You can add an overhead USB (UVC) camera for a second view.
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.
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.
International bank cards — Visa, Mastercard and more. Payment happens on a secure payment page.
Yes. SO-ARM101 stays on sale for classrooms and labs that standardised on it; write to us and we will send the link.
Buy or ask
Compatibility, a lab order, the platform — write and we will answer.
Or write to us directly: hello@robonine.com
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