SO-101

Robot / hardware build

Teleoperation Manipulation

A printable robot arm for teleoperation and robot-learning experiments. [1]

Build & first use →Parts & prices Official website Source code Bill of materials

For: Builders exploring arm teleoperation and robot learning [1]
Cost: USD 150.28 follower only, 7.4 V servosUSD 273.07 follower + leader, 7.4 V servosKnown parts subtotals, US · prices checked Oct 4, 2026 · Parts and pricesNot included: host computer able to run LeRobot, FDM 3D printer (220 x 220 mm bed or larger), precision screwdriver set with Phillips #0 and #1 and shipping and tax.
Source rights: Some licenses are unresolved. Review licenses
Unknowns: tools not fully established. Review gaps

Source researched · Not tested by us
Sources checked Sep 30, 2026 · Research details

SO-101 follower arm. Photo: SO-ARM contributors · Apache 2.0.

See the leader arm

Photo: SO-ARM contributors · Apache 2.0.

Licenses & related hardware

Ecosystem: LeRobot
License: Apache-2.0 · license not fully assessed for documentation · Details by part

Requirements · Research details and dates

Overview

SO-101 is a small robot arm with a 3D-printed frame and motor-driven joints. It works with LeRobot software for remote control and robot-learning experiments. [1] [5] [6]

In a two-arm setup, a person moves the arm called the leader. The powered arm, called the follower, follows those movements. This is called teleoperation: controlling a robot by moving a separate device. The leader and follower are separate arms, which is why the parts list has prices for both a single arm and a pair. [1] [5]

3D preview

SO-101 assembly. Assembly geometry from the upstream STEP. Purchased components are represented; their manufacturing sources and physical fit are not established by this preview.

The 3D preview loads after the page.

Drag to orbit · Scroll or pinch to zoom · Right-drag to pan. Use the view buttons for front, side and top views. The tree shows names supplied by the source; unnamed bodies remain labeled as such.

Download original STEP · File checksums and provenance

Separate bodies can be inspected in the model tree. Explode is a viewing aid, not an assembly sequence.

Model sources

The preview uses the linked original design. Source grouping is retained where present; the caption identifies whether this is an assembly or one component.

Source, license and scale

Source: TheRobotStudio contributors, revision 5f6d2b876a53a4872e405b991dd925556c9e38a4. Original and preview: Apache-2.0. Preview conversion by Open Source Robotics; original file unchanged. Preview coordinates are centered and rounded to six decimal places. STEP preview triangulated in millimetres. No physical part tested.

Viewer: three-cad-viewer 5.0.7 (MIT license). Confirm scale and manufacturing settings before printing.

What you need

Operating system

macOS on Apple silicon: software dependencies were resolved, but installation and robot operation were not tested. Follow the LeRobot installation guide for platform requirements.

[9] [90]

Host computer

A host computer with USB access and a compatible LeRobot environment; our software dependency check used macOS on Apple silicon and Python 3.12, without installing or running the robot software.

Software dependencies checked; installation and hardware operation remain unverified.

[8] [9] [90]

Dependencies

LeRobot v0.6.1, selected for dependency checks; not tested with the robot
Python 3.12, used for dependency checks
core_scripts and feetech extras
Platform-specific Torch and FFmpeg prerequisites

[9] [90]

Hardware & parts

Open the parts list with US prices for 2 configurations.

Upstream bill of materials [5]

Hardware configuration

Desktop manipulator

[1]

Assembly & first use

Project documentation [1]

Assembly

Source and print the matched parts; configure motors individually before mechanical assembly, then calibrate the assembled leader and follower.

Follow the pinned guide for the chosen configuration; hardware operation remains untested.

[8]

Calibration

Configure motor IDs, then calibrate the leader and follower using the LeRobot SO-101 guide; save calibration generated for the actual arms.

[8]

Build files and instructions follow below.

Build files and instructions

This route is for one SO-101 leader and follower pair. Choose one matching pair of print plates: the README lists Ender plates for its 220 × 220 mm bed option and Prusa plates for its 205 × 250 mm option. The repository also contains SO-100 files and alternate parts that should not all be printed. Our manifest resolves the 18 print-file links in the reviewed README, but does not establish individual-part quantities or mechanical fit. [5] [91]

Download the pinned hardware repository or browse CAD and print files.
Open the configuration-specific parts list and print-file manifest with individual download links. A spreadsheet-ready CSV is also available.
Follow the LeRobot v0.6.1 assembly, motor setup and calibration guide, including its assembly videos. Then use the separate SO-101 teleoperation instructions, retaining the same robot IDs used for calibration. [10]
Use the pinned LeRobot software source and its installation instructions. The hardware/software combination remains a candidate until tested together. [8] [9]

Cost & sourcing

US delivery · USD · Configuration-specific parts estimates

Build configuration

Leader-follower teleoperation with LeRobot

Known parts subtotal · additional costs unresolved

USD 273.07

Prices dated Oct 4, 2026.

Baseline: nothing owned

BOM coverage & pricing basis

BOM coverage: partial · Pricing coverage: 8/11 procurement groups · First-task budget: incomplete

Upstream BOM table reconciled line by line, printed parts mapped and sliced. Not complete: the pinned LeRobot SO-101 assembly guide uses M2x6 and M3x6 screws, which neither BOM table lists, and no pinned source states that they ship with the servos. Camera not required for this first task.

Known required subtotal across all layers: USD 273.07. Unpriced: Host computer able to run LeRobot, FDM 3D printer (220 x 220 mm bed or larger), Precision screwdriver set with Phillips #0 and #1, Shipping and tax.

Cost layers & unpriced requirements

Cost layers

Layer	Known expenditure	Unpriced requirements
Purchased parts	USD 226.81–USD 232.72	—
Printed parts: material purchase	USD 14.39–USD 16.49	—
Fabricated parts	No requirements recorded	—
Power & cabling	USD 31.87	—
Host computer	Unpriced	Host computer able to run LeRobot
Sensors & cameras	No requirements recorded	—
Tools	Unpriced	FDM 3D printer (220 x 220 mm bed or larger), Precision screwdriver set with Phillips #0 and #1
Shipping & tax	Unpriced	Shipping and tax

Parts & sourcing

Purchases combine repeated requirements before rounding to supplier packs. Shared purchases appear once. Printed material consumption and whole-spool purchase costs are different. Under “Other offers & price history”, historical observations may be excluded from today's subtotal. Broken or unavailable listings do not count.

Part / requirement	Quantity & ownership	Lowest eligible purchase
Feetech STS3215 7.4 V servo, 1/345 gear (C001)Required · Purchased parts	7 each	USD 111.93 WowRobo Robotics7 pack(s) × 1 each; minimum 1 pack(s) · in stockChecked by us · Oct 4, 2026 Price sources Feetech STS3215 C001 Servo – 7.4V 19.5KG 1/345 Servo for SO-ARM100/101 · WowRobo contact / about page Requirement notes Six follower joints plus one leader joint. Other offers & price history Alibaba listing linked from upstream READMEUSD 13.89 / 1 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Upstream README "Unit Cost (US)" column at pinned revision 5f6d2b8 (2026-09-23). The figures (13.89 servo; 121.94 and 229.88 totals) appear unchanged in every README revision from 2415d54 (2025-06-02) to the pinned revision (20 consecutive revisions; retained source evidence), so the price is dated to that earliest revision. Supplier MOQ not independently checked; the table prices single units for the listed amount.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan WowRobo RoboticsUSD 15.99 / 1 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Variant 'Single Piece(15.99/pcs)' available=True per product JSON; stock quantity not shown.Feetech STS3215 C001 Servo – 7.4V 19.5KG 1/345 Servo for SO-ARM100/101 · WowRobo contact / about page WowRobo RoboticsUSD 74.95 / 5 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Variant '5 Pieces(14.99/pcs)' available=True per product JSON; stock quantity not shown.Feetech STS3215 C001 Servo – 7.4V 19.5KG 1/345 Servo for SO-ARM100/101 · WowRobo contact / about page WowRobo RoboticsUSD 139.90 / 10 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Variant '10 Pieces(13.99/pcs)' available=True per product JSON; stock quantity not shown.Feetech STS3215 C001 Servo – 7.4V 19.5KG 1/345 Servo for SO-ARM100/101 · WowRobo contact / about page
Feetech STS3215 7.4 V servo, 1/191 gear (C044)Required · Purchased parts	2 each	USD 31.98 WowRobo Robotics2 pack(s) × 1 each; minimum 1 pack(s) · in stockChecked by us · Oct 4, 2026 Price sources Feetech STS3215 C044 Servo – 7.4V 16KG 1/191 Servo for SO-ARM101 · WowRobo contact / about page Requirement notes Leader arm. Other offers & price history Alibaba listing linked from upstream READMEUSD 13.89 / 1 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan WowRobo RoboticsUSD 15.99 / 1 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.Feetech STS3215 C044 Servo – 7.4V 16KG 1/191 Servo for SO-ARM101 · WowRobo contact / about page WowRobo RoboticsUSD 74.95 / 5 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.Feetech STS3215 C044 Servo – 7.4V 16KG 1/191 Servo for SO-ARM101 · WowRobo contact / about page WowRobo RoboticsUSD 139.90 / 10 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.Feetech STS3215 C044 Servo – 7.4V 16KG 1/191 Servo for SO-ARM101 · WowRobo contact / about page
Feetech STS3215 7.4 V servo, 1/147 gear (C046)Required · Purchased parts	3 each	USD 47.97 WowRobo Robotics3 pack(s) × 1 each; minimum 1 pack(s) · in stockChecked by us · Oct 4, 2026 Price sources Feetech STS3215 C046 Servo – 7.4V 14.4KG 1/147 Servo for SO-ARM101 · WowRobo contact / about page Requirement notes Leader arm. Other offers & price history Alibaba listing linked from upstream READMEUSD 13.89 / 1 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan WowRobo RoboticsUSD 15.99 / 1 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.Feetech STS3215 C046 Servo – 7.4V 14.4KG 1/147 Servo for SO-ARM101 · WowRobo contact / about page WowRobo RoboticsUSD 74.95 / 5 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.Feetech STS3215 C046 Servo – 7.4V 14.4KG 1/147 Servo for SO-ARM101 · WowRobo contact / about page WowRobo RoboticsUSD 139.90 / 10 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.Feetech STS3215 C046 Servo – 7.4V 14.4KG 1/147 Servo for SO-ARM101 · WowRobo contact / about page
Serial bus servo driver board (Waveshare-type, USB)Required · Purchased parts	2 each	USD 24.94 Wonrabai Electronics2 pack(s) × 1 each; minimum 1 pack(s) · in stockChecked by us · Oct 4, 2026 Price sources Serial Bus Servo Driver Board, Support 253 ST/SC Serial Bus Servos Other offers & price history Amazon listing linked from upstream READMEUSD 10.60 / 1 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan Wonrabai ElectronicsUSD 12.47 / 1 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Listing page fetched and buy box read on 2026-10-04; seller: Wonrabai Electronics.Serial Bus Servo Driver Board, Support 253 ST/SC Serial Bus Servos
USB-A to USB-C cableRequired · Power & cabling	2 each	USD 7.19 etguuds1 pack(s) × 2 each; minimum 1 pack(s) · in stockChecked by us · Oct 4, 2026 Price sources etguuds 6.6ft USB A to USB C Cable, 2Pack Fast Charging Cord Type C Charger Requirement notes Upstream buys one 2-pack for either configuration. Other offers & price history Amazon listing linked from upstream READMEUSD 7.00 / 2 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan etguudsUSD 7.19 / 2 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Listing page fetched and buy box read on 2026-10-04; seller: etguuds.etguuds 6.6ft USB A to USB C Cable, 2Pack Fast Charging Cord Type C Charger
5 V 4 A power supply, 5.5 x 2.1 mm barrelRequired · Power & cabling	2 each	USD 24.68 Mo-gu2 pack(s) × 1 each; minimum 1 pack(s) · in stockChecked by us · Oct 4, 2026 Price sources Facmogu 5V 4A AC to DC Power Supply Adapter, AC 100-240V to DC 5 Volt 4 Amp Other offers & price history Amazon listing linked from upstream READMEUSD 10.00 / 1 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan Mo-guUSD 12.34 / 1 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Listing page fetched and buy box read on 2026-10-04; seller: Mo-gu.Facmogu 5V 4A AC to DC Power Supply Adapter, AC 100-240V to DC 5 Volt 4 Amp
Small bar / trigger clamp for mounting the arm baseRequired · Purchased parts	4 each	USD 9.99 Partstock1 pack(s) × 4 each; minimum 1 pack(s) · in stockChecked by us · Oct 4, 2026 Price sources TAODAN 4PCS 4 Inch Trigger Quick Grip Clamps Bar Clamp Trigger Quick Grip Clamp Single Hand Ratchet Woodworking Clamp for Wood Bonding Processes Other offers & price history Amazon listing linked from upstream README (two-arm table)USD 9.00 / 4 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan Amazon listing linked from upstream README (follower table)USD 5.00 / 2 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan PartstockUSD 9.99 / 4 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Listing page fetched and buy box read on 2026-10-04; seller: Partstock.TAODAN 4PCS 4 Inch Trigger Quick Grip Clamps Bar Clamp Trigger Quick Grip Clamp Single Hand Ratchet Woodworking Clamp for Wood Bonding Processes Mr. PenUSD 7.95 / 2 each; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Listing page fetched and buy box read on 2026-10-04; seller: Mr. Pen.Mr. Pen- Bar Clamps for Woodworking, 6", 2 Pack, Orange
Precision screwdriver set with Phillips #0 and #1Required · Tools	1 each	Unpriced Other offers & price history Amazon listing linked from upstream READMEUSD 6.00 / 1 each; minimum 1 pack(s). Upstream-published · Jun 2, 2025 · unknown, link unknown.Same observation notes as Feetech STS3215 7.4 V servo, 1/345 gear (C001) above.SO-ARM100 README bill of materials · SO-ARM100 README commit history and price presence scan Amazon.com marketplace seller (no featured offer)Unpriced / 1 each; minimum 1 pack(s). Checked by us · Unknown · out of stock, link working.Listing page fetched and buy box read on 2026-10-04. No featured offer: currently unavailable.Small Precision Phillips and Slotted Screwdriver Set 8 Sizes PH000 PH00 PH0 PH1 and Flat Head Slotted 1.5 2.0 2.5 3.0mm for Electronics Toys Computer, Watch Repair, Orange, SKZUSA0148
Host computer able to run LeRobotRequired · Host computer	1 each	Unpriced Requirement notes Required to run LeRobot; not in the upstream BOM table. Other offers & price history No offer recorded.
FDM 3D printer (220 x 220 mm bed or larger)Required · Tools	1 each	Unpriced Requirement notes Required for the self-print route; upstream links printing services as an alternative. Other offers & price history No offer recorded.
PLA+ filament, 1.75 mmRequired · Printed parts: material purchase	447.4 g	USD 14.39 eSUN Bio New Material1 pack(s) × 1000 g; minimum 1 pack(s) · in stockChecked by us · Oct 4, 2026 Price sources eSUN PLA+ Filament 1.75mm Black 1KG,PLA Pro 3D Printer Filament Requirement notes Material consumption: 388.4–447.4 g. Print method and assumptions are under Printing & required equipment. Other offers & price history eSUN Bio New MaterialUSD 14.39 / 1000 g; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Listing page fetched and buy box read on 2026-10-04; seller: eSUN Bio New Material.eSUN PLA+ Filament 1.75mm Black 1KG,PLA Pro 3D Printer Filament OVERTURE 3DUSD 16.49 / 1000 g; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.Listing page fetched and buy box read on 2026-10-04; seller: OVERTURE 3D.OVERTURE PLA Plus (PLA+) 3D Printer Filament 1.75mm, 1kg Black
PLA+ filament, 1.75 mmRequired · Printed parts: material purchase	458.1 g	Included in shared purchase above Requirement notes Material consumption: 397–458.1 g. Print method and assumptions are under Printing & required equipment. Other offers & price history eSUN Bio New MaterialUSD 14.39 / 1000 g; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.eSUN PLA+ Filament 1.75mm Black 1KG,PLA Pro 3D Printer Filament OVERTURE 3DUSD 16.49 / 1000 g; minimum 1 pack(s). Checked by us · Oct 4, 2026 · in stock, link working.OVERTURE PLA Plus (PLA+) 3D Printer Filament 1.75mm, 1kg Black

Printing & required equipment

follower-frame: 388.4–447.4 g material consumption; buy whole supplier packs.

Print method, fit & assumptions

Slicer: PrusaSlicer-2.9.6 based on Slic3r (with GUI support), upstream plate STL/SO101/Follower/Ender_Follower_SO101.stl for a 220 x 220 mm bed; low = 2 perimeters, high = 3 perimeters (PrusaSlicer default); other unstated settings are PrusaSlicer defaults. Mass includes supports and skirt (retained source evidence). Upstream settings applied: PLA+, 0.4 mm nozzle, 0.2 mm layers, 15% infill, supports everywhere except slopes over 45 degrees. Supports are generated in horizontal screw holes too (upstream asks to block them), a slight overestimate. Brim 0 mm; single extruder, so no purge. One successful print is assumed: no allowance for failed prints or reprints. The plate file contains exactly the mapped individual files (equal solid volume). WaveShare mounting plate selected; Seeed plate is the excluded alternative. Geometric cross-check, solid volumes: Base_motor_holder_SO101.stl: 23.7 cm3 solid; Base_SO101.stl: 122.7 cm3 solid; Motor_holder_SO101_Base.stl: 13.3 cm3 solid; Motor_holder_SO101_Wrist.stl: 13.9 cm3 solid; Under_arm_SO101.stl: 92.9 cm3 solid; Upper_arm_SO101.stl: 117.3 cm3 solid; Rotation_Pitch_SO101.stl: 68.8 cm3 solid; Wrist_Roll_Pitch_SO101.stl: 32.3 cm3 solid; WaveShare_Mounting_Plate_SO101.stl: 9.1 cm3 solid; Moving_Jaw_SO101.stl: 20.7 cm3 solid; Wrist_Roll_Follower_SO101.stl: 56.6 cm3 solid.

leader-frame: 397–458.1 g material consumption; buy whole supplier packs.

Print method, fit & assumptions

Slicer: PrusaSlicer-2.9.6 based on Slic3r (with GUI support), upstream plate STL/SO101/Leader/Ender_Leader_SO101.stl for a 220 x 220 mm bed; low = 2 perimeters, high = 3 perimeters (PrusaSlicer default); other unstated settings are PrusaSlicer defaults. Mass includes supports and skirt (retained source evidence). Upstream settings applied: PLA+, 0.4 mm nozzle, 0.2 mm layers, 15% infill, supports everywhere except slopes over 45 degrees. Supports are generated in horizontal screw holes too (upstream asks to block them), a slight overestimate. Brim 0 mm; single extruder, so no purge. One successful print is assumed: no allowance for failed prints or reprints. The plate file contains exactly the mapped individual files (equal solid volume). WaveShare mounting plate selected; Seeed plate is the excluded alternative. Geometric cross-check, solid volumes: Base_motor_holder_SO101.stl: 23.7 cm3 solid; Base_SO101.stl: 122.7 cm3 solid; Motor_holder_SO101_Base.stl: 13.3 cm3 solid; Motor_holder_SO101_Wrist.stl: 13.9 cm3 solid; Under_arm_SO101.stl: 92.9 cm3 solid; Upper_arm_SO101.stl: 117.3 cm3 solid; Rotation_Pitch_SO101.stl: 68.8 cm3 solid; Wrist_Roll_Pitch_SO101.stl: 32.3 cm3 solid; WaveShare_Mounting_Plate_SO101.stl: 9.1 cm3 solid; Handle_SO101.stl: 69.6 cm3 solid; Trigger_SO101.stl: 11.2 cm3 solid; Wrist_Roll_SO101.stl: 39.8 cm3 solid.

Required host computers, cameras and tools are separate from the Parts total. They appear in the required subtotal only where priced or explicitly owned. Labor: unknown.

Prices are dated US listings or upstream-published figures, not checkout guarantees. Shipping and tax assumptions remain visible above. We don’t earn from these links.

Download reviewed data

Full cost and sourcing receipt (JSON)

SO-101 follower + leader, 7.4 V servos baseline CSV

SO-101 follower only, 7.4 V servos baseline CSV

Earlier upstream estimates and vendor offers

Earlier estimates

These prices are from the project's US parts list for the 7.4V version. They do not cover a complete build.

Version	Price
One arm (follower)	USD 121.94 [5] Parts estimate
Two arms (follower and leader)	USD 229.88 [5] Parts estimate

Both prices were checked 2026-09-29. The following applies to both versions.

Included	Servos, controller boards, cables, power supplies, clamps and screwdrivers
Not included	Printed frame; Camera; Host computer; Assembly work
Stock	Individual vendor stock not rechecked.
Delivery and tax	Delivery and taxes are not established; no delivered total is quoted.

Price details

Maintainer-published parts subtotal; vendor prices have not been re-quoted.

Upstream US price column · Checked 2026-09-29 · Quantity 1

Printed parts and host computer; camera and learning workload requirements depend on intended task.

What the parts cost now

These prices cover the 7.4 V servo configuration. At US prices checked on October 4, 2026, the known parts subtotal is USD 273.07 for a leader and follower pair and USD 150.28 for a follower alone. The README also offers 12 V follower servos, which need a 12 V 5 A or larger power supply instead of the 5 V one; that option is outside this estimate. That covers the servos, controller boards, cables, power supplies, clamps and one 1 kg spool of PLA+ for the printed frame. Servos are most of it: the lowest current listing we found sells each STS3215 for USD 15.99, from a store whose facility is in China and whose shipping is calculated at checkout. [5] [92]

These are subtotals, not complete budgets. The LeRobot assembly guide uses M2×6 and M3×6 screws that neither parts list includes, and suitable screwdrivers, shipping, tax, a host computer and a 3D printer are extra. The screwdriver listing is unavailable, so its historical USD 6 is excluded unless a usable offer is established; no purchase is needed if suitable tools are already owned. Our printing estimate comes from slicing the README's Ender print plates (220 × 220 mm bed) with its settings, two or three walls, and PrusaSlicer defaults for anything it leaves unstated: about 390–460 g of PLA+ per arm, including supports, if every print succeeds. It slightly overstates supports, because it does not block them in screw holes as the README asks; the receipt lists these assumptions. The README's own US table, unchanged since June 2025, lists USD 229.88 and USD 121.94; those totals include a USD 6 screwdriver set and leave out printing. See the configuration cost breakdown. [5] [8] [92]

Project notes

Printing the frame is one part of the work

The repository provides printable mechanical files and STEP files. The LeRobot guide configures motors individually before mechanical assembly, then calibrates the assembled leader and follower. Keep the guide for your chosen configuration alongside its power-supply and motor instructions. [1] [6]

What we checked

Source-researched profile with file and dependency-resolution checks. No physical assembly, software installation, calibration or teleoperation test performed. No independent human technical review.

Research scope and retained receipts

We preserved 241 hardware source files and resolved 75 dependencies for a candidate macOS ARM64, Python 3.12 environment using the core_scripts and feetech extras. The check receipt and hashed dependency list record that scope. Dependency resolution does not establish a successful installation or working robot. We have not run this setup, configured its motors or calibrated either arm; calibration must be generated on the actual hardware. [90] [8]

Not yet established

A limitations summary
Requirements: tools

Updates

Upstream last updated: Sep 23, 2026 [2]
Latest release: Not established
Profile updated: Oct 4, 2026
Sources last checked: Sep 30, 2026
Next review: Oct 30, 2026
Reviewed revision: 5f6d2b8 · combined hardware and software repository

Source files and licenses

Mechanical design and control software sources are available. Complete electronics/servo firmware sources and all component licenses are not established; no blanket fully-open claim.

Layer	Availability / license
mechanical design	available · Apache-2.0 Repository root license; this does not assign a license to separately purchased components. [6] [3]
electronics	not found · License not fully assessed No complete controller/servo electronics design or servo firmware source was established from the inspected build guide and design repository. Off-the-shelf component sources require further investigation. [1] [5]
firmware	not found · License not fully assessed No complete controller/servo electronics design or servo firmware source was established from the inspected build guide and design repository. Off-the-shelf component sources require further investigation. [1] [5]
software	available · Apache-2.0 Control/training library; not servo firmware. [1] [7]
documentation	available · License not fully assessed Build guide available; this profile does not assign a blanket documentation/media license. [1]

This entry covers the physical arm and teleoperation build; a particular learned policy or training dataset is not included.

Source availability has boundaries

The arm design and LeRobot control software have Apache-2.0 root licenses. The purchased controllers and servos need separate checks: the reviewed repository and guide did not establish complete electronics designs or servo firmware sources. See the source files and licenses for the available layers. [1] [3] [5] [7]

We have not assembled or calibrated this configuration; build time and task performance remain unmeasured.

References

Each source links to the exact revision we read. “Used for” shows where this page relies on it.

Project sources

S001 SO-101 documentation
A printable robot arm for teleoperation and robot-learning experiments.
Revision, date & where cited
Hugging Face / LeRobot contributors · huggingface.co · Overview · Accessed Sep 29, 2026

Used for: Overview, Hardware & parts, Assembly & first use, Printing the frame is one part of the work and 1 more
S002 SO-101 repository revision
Revision, date & where cited
github.com · revision 5f6d2b8 · Accessed Sep 29, 2026

Used for: What we checked
S003 TheRobotStudio/SO-ARM100: LICENSE
Revision, date & where cited
github.com · revision 5f6d2b8 · LICENSE file · Accessed Sep 29, 2026

Used for: Source files and licenses
S005 SO-101 upstream bill of materials
US-column reference subtotals: $121.94 for one follower and $229.88 for follower plus leader. Printing is described separately. Vendor prices, stock, delivery and taxes have not been re-quoted.
Revision, date & where cited
github.com · revision 5f6d2b8 · Parts for One Follower Arm; Parts For Two Arms; Printing the Parts · Accessed Sep 29, 2026

Used for: Overview, Hardware & parts, Build files and instructions, Cost & sourcing and 1 more
S006 SO-101 design files
Printable mechanical files are available in the STL directory; STEP files are also present in the repository.
Revision, date & where cited
github.com · revision 5f6d2b8 · STL and STEP directories · Accessed Sep 29, 2026

Used for: Overview, Printing the frame is one part of the work, Source files and licenses
S007 LeRobot software license
LeRobot repository root license is Apache-2.0 with third-party notices.
Revision, date & where cited
Hugging Face / LeRobot contributors · github.com · revision e0d5021 · Accessed Sep 29, 2026

Used for: Source files and licenses
S008 LeRobot v0.6.1 so101.mdx
Configure motors individually, assemble the selected leader and follower, then calibrate each arm using its actual port and ID.
Revision, date & where cited
Hugging Face / LeRobot contributors · github.com · revision 7e241bd · Pinned source / audit snapshot, September 30, 2026 · Accessed Sep 30, 2026

Used for: What you need, Assembly & first use, Build files and instructions, Cost & sourcing and 1 more
S009 LeRobot v0.6.1 installation.mdx
Versioned installation instructions specify Python and platform-dependent dependencies; workflow extras select the required features.
Revision, date & where cited
Hugging Face / LeRobot contributors · github.com · revision 7e241bd · Pinned source / audit snapshot, September 30, 2026 · Accessed Sep 30, 2026

Used for: What you need, Build files and instructions
S010 LeRobot v0.6.1 SO-101 teleoperation instructions
SO-101 leader/follower teleoperation commands use the same IDs as calibration; the rest of the tutorial covers optional recording and training.
Revision, date & where cited
Hugging Face / LeRobot contributors · github.com · revision 7e241bd · Teleoperate section, pinned v0.6.1 · Accessed Sep 30, 2026

Used for: Build files and instructions

Our checks and receipts

S090 Build-file and software-check receipt
Revision, date & where cited
Open Source Robotics · opensourcerobotics.dev · Pinned source / audit snapshot, September 30, 2026 · Accessed Sep 30, 2026

Used for: What you need, What we checked
S091 Configuration-specific print-file manifest
Revision, date & where cited
Open Source Robotics · opensourcerobotics.dev · Pinned source / audit snapshot, September 30, 2026 · Accessed Sep 30, 2026

Used for: Build files and instructions
S092 SO-101 US cost and sourcing estimate receipt
Line-level US offers, price dates, printed-part slicing and rollups for both SO-101 configurations.
Revision, date & where cited
Open Source Robotics · opensourcerobotics.dev · Rollups as of 2026-10-04 · Accessed Oct 4, 2026

Used for: Cost & sourcing

Videos

S093 Want to help with building robots? (YouTube video)
Video from the project’s own channel (therobotstudio), linked from the project’s own documentation. Not reviewed by us for accuracy.
Revision, date & where cited
YouTube video therobotstudio · youtube.com · Accessed Oct 4, 2026
S095 therobotstudio (YouTube channel)
The project’s own YouTube channel, found by searching YouTube and checked against the channel page. Not reviewed by us for accuracy.
Revision, date & where cited
YouTube channel therobotstudio · youtube.com · Accessed Oct 4, 2026

Correction guidance · Discussion is not enabled · Profile format 0.7.0-draft.5

Change history

2026-09-30 — Edited the opening and removed repeated qualifications; clarified source labels, configuration costs and further reading. Source-check dates are unchanged.

2026-09-30 — Added an introduction explaining the leader and follower, with credited project photographs. Simplified the cost presentation.

2026-09-30 — Added configuration-specific build resources, print-file manifests and scoped software-check evidence; physical testing remains unperformed.

2026-10-04 — Staged v0.7 cost and sourcing estimate: line-level BOM, US offers and printed-part mapping. Not yet reviewed or published.

2026-10-04 — Staged draft.5 estimate excludes confirmed broken/unavailable listings while preserving historical prices. Not published.

2026-10-04 — Added 2 YouTube reference(s) (S093, S095): official channel or videos linked from the pinned upstream sources. Existing claims, source-check dates and evidence are unchanged.