TRLC-DK1 open-source 7-DoF robot arm, 3D render from TRLC-DK1-Follower_v0.3.0.step

TRLC-DK1

Leader/follower arm dev kit: Damiao-motor follower, Dynamixel leader, LeRobot plugin.

Start the build

What it is

TRLC-DK1 is the open developer kit from The Robot Learning Company: a 6-joint follower arm with a parallel gripper (two prismatic fingers in the URDF), powered by Damiao DM4340 motors on joints 1 to 3 and DM4310 motors on joints 4 to 6 and the gripper over CAN, paired with a passive leader built from seven Dynamixel XL330-M077-T servos and a GELLO-style handle and trigger. The repo carries the v0.3.0 follower STEP assembly (about 42 MB), a follower URDF with GLB visual and STL collision meshes, leader, gripper-finger and framing STLs plus a Bambu Lab 3MF, and a Python package that plugs into LeRobot with position and impedance control and gravity compensation; the leader's v0.2.0 source CAD is only shared as an Autodesk viewer link. The docs site publishes a leader parts list and assembly guide but no follower BOM (the company ships kits fully assembled and calibrated), and no price appears on the repo, docs or company site. The whole repo is under an Apache-2.0 LICENSE, with vendored code credited to DM_Control_Python and GELLO (MIT) and LeRobot (Apache-2.0).

Licenses

Hardware
Apache-2.0
Software
Apache-2.0
Docs
Not published

Degrees of freedom

7 DoF arm 6gripper 1

Breakdown source

Serial armLeader-follower pairsource

Auto-assembled, not yet reviewed

Source record

Source
797 stars, last push 2026-07-13
HW license
Apache-2.0
Cost
not published
Lifecycle
Active
Engine
v3.1.1
Checked
Model
TRLC-DK1-Follower_v0.3.0.step@12f5368rendered 2026-10-02
Envelope
166 × 255 × 524 mmas modelled, default pose

Maintain TRLC-DK1? Claim this page to correct it.

Parts and cost

6 rows

Cost to build

The sources do not publish a cost total. The rows below are what they list, without a sum.

TRLC-DK1 parts, as the source lists them. Prices are the source's, not checked against vendors.

TRLC-DK1 bill of materials
PartQtySpecSourceConfidence
Dynamixel XL330-M077-TLeader arm: 6 joint servos plus the gripper trigger servo
7Robotis XL330 servo, all seven leader motors are xl330-m077 in the leader driver
Robotisnot listed in source BOMrobot-learning-co docs, Leader Arm Assembly page, Components table
high
Waveshare Serial Bus Servo Driver BoardLeader arm servo bus interface
1Waveshare serial bus servo driver board
Amazonnot listed in source BOMrobot-learning-co docs, Leader Arm Assembly page, Components table
high
3D-printed Links using PLA(-CF)Leader link set; the source table gives no quantity, the STLs and a Bambu Lab 3MF are in hardware/leader_STLs
1PLA-CF recommended, 0.4 mm nozzle, 0.12 mm layers, 15% gyroid infill, supports on
Bambu Lab storenot listed in source BOMrobot-learning-co docs, Leader Arm Assembly page, Components table and 3D Printing section
high
5V DC Power Supply (2 Pole or 5.5x2.1 Power Jack)Leader arm supply
15 V DC, 2-pole or 5.5x2.1 jack
Amazonnot listed in source BOMrobot-learning-co docs, Leader Arm Assembly page, Components table
high
M2x4 InsertsLeader arm threaded inserts
4M2x4 inserts
Amazonnot listed in source BOMrobot-learning-co docs, Leader Arm Assembly page, Components table
high
M2x5 Screws (e.g. ISO 4762)Leader arm screws; Dynamixel frame and horn screws come with the servos
4M2x5 socket head, e.g. ISO 4762
Amazonnot listed in source BOMrobot-learning-co docs, Leader Arm Assembly page, Components table
high

Rows from the source's own parts list 6

Leader Arm Assembly, Components tablehtml

Source rowQtyPrice and vendorLine
Dynamixel XL330-M077-T
7
en.robotis.comno price listed
L143
Waveshare Serial Bus Servo Driver Board
1
amazon.comno price listed
L143
3D-printed Links using PLA(-CF)
store.bambulab.comno price listed
L143
5V DC Power Supply (2 Pole or 5.5x2.1 Power Jack)
1
amazon.comno price listed
L143
M2x4 Inserts
4
amazon.comno price listed
L143
M2x5 Screws (e.g. ISO 4762)
4
amazon.comno price listed
L143

How to build

6 steps

Upstream step marks a step taken from the linked guide.

  1. Mount the follower

    Mount TRLC-DK1 with table clamps (WORKPRO quick-release clamps) or with M5 screws on 3060 or 4080 aluminium extrusion; the docs give measurements for custom mounts.

    Upstream stepdocs.robot-learning.co/1_unboxing_and_setup

  2. Connect power and data

    Connect the power supply (200 W solo, 450 W bimanual) and the leader and follower power cables. Every follower needs two USB cables, one for the CAN adapter and one for the wrist camera, and the host needs USB 3.0 ports.

    Upstream stepdocs.robot-learning.co/1_unboxing_and_setup

  3. Print the leader links

    To build or repair a leader, print the leader STLs in PLA-CF with a 0.4 mm nozzle, 0.12 mm layers, 15% gyroid infill and supports on; a Bambu Lab 3MF project is provided.

    Upstream stepdocs.robot-learning.co/guides/leader

  4. Assemble the leader

    Install the M2 inserts, then assemble every Dynamixel at its absolute zero mark with 4 long screws per frame and 4 short screws per output horn. Choose the regular wrist or the top-down wrist (link4-5-flipped), then mount the GELLO handle and the driver board.

    Upstream stepdocs.robot-learning.co/guides/leader

  5. Set up the leader motors

    Run the LeRobot motor setup for the dk1_leader, connecting one motor at a time, then daisy-chain all motors.

    Upstream stepdocs.robot-learning.co/guides/leader

  6. Install and teleoperate

    Find the leader and follower ports with uv run lerobot-find-port, put leader and follower in the same configuration (a mismatch can cause a fast, aggressive jump), then run uv run lerobot-teleoperate with --robot.type=dk1_follower and --teleop.type=dk1_leader.

    Upstream stepdocs.robot-learning.co/3_teleoperation
Print timenot published
Assembly timenot published

Wiring, power and firmware are safety-relevant and shown for reference only. Check them against the source before building.

How reproducible

How confidently this design builds into a working robot, from what its sources publish: each criterion's points, quality tier and evidence.

65/100Partial source coverage, unverified
  • metCAD / mesh present2 editable CAD files (STEP), including an assembly + 37 mesh files20/20

    Quality tier 3 of 3

  • partialBOM evidenceBOM on docs.robot-learning.co, not inspected by the engine10/20

    Quality tier 1 of 5

  • partialWiring diagramReviewedThe docs' Electrical Setup draws the external power wiring of a leader-follower pair (supply, converter, E-stop). The follower's internal CAN wiring is not published, so this is partial.7.5/15

    Quality tier 1 of 3

    Reviewed override, 2026-10-02

    Evidence on docs.robot-learning.co

    Engine alone: missing at tier 0 (no wiring diagram found)

  • metFirmware linkedhost control code in the repo, no MCU firmware10/10

    Quality tier 2 of 3

  • partialBuild instructionsexternal build guide linked, not inspected by the engine7.5/15

    Quality tier 1 of 3

  • metOSHW-compatible licenseApache-2.0 (from repository license)10/10

    Quality tier 2 of 2

  • missingKnown reproductionsno verified builds yet0/10

    Quality tier 0 of 2

    Only build reports a maintainer or admin has reviewed count here.

Engine v3.1.1 at 12f5368, 1 item reviewed by hand

How this score is computed

Files and sim

12 files

Files stay in the upstream repository under their own licenses; these links open them there. The 3D model on this page is Motari's conversion of the file named under Simulation.

Simulation

Robot description files a simulator or CAD tool can load, linked at the commit they were found.

The 3D specimen on this page is converted from hardware/TRLC-DK1-Follower_v0.3.0.step at 12f5368.

Builds

0 reviewed

No reviewed builds of TRLC-DK1 yet.

A build log records the evidence (photos, a video, your repository), what the build cost, how long it took and what you changed. Each one is checked by Motari (until a maintainer claims this page) before it shows here, and reviewed builds count toward the reproducibility score.

Sources

Where the facts come from

Last push to robot-learning-co/trlc-dk1: 2026-07-13 (checked 2026-10-02)

Related links

How this page was made

Assembled from public sources on 2026-09-30, not yet reviewed by the maintainer. Each figure links to where it is stated; a value the sources do not state reads "not published". Last source review: 2026-09-30 robot-learning-co/trlc-dk1@12f5368 README, LICENSE, tree.

Original files stay intact and separately licensed; Motari adds only the summary on this page. Maintainer? Request a correction or removal.

Badge for the README

Maintain TRLC-DK1? Show its reproducibility score in the project's README. The badge links back to this page and updates with the score.

Badge: reproducibility 65/100

Markdown
[![Motari reproducibility score for TRLC-DK1](https://motari.io/api/v1/badge/trlc-dk1)](https://motari.io/r/trlc-dk1)
HTML
<a href="https://motari.io/r/trlc-dk1"><img src="https://motari.io/api/v1/badge/trlc-dk1" alt="Motari reproducibility score for TRLC-DK1" height="20"></a>

Not fully met yet: bom evidence (partial), wiring diagram (partial), build instructions (partial). The score is read from the project's own sources, so publishing what is missing is what raises it. A score of 90 or more needs a reviewed build. How the score is computed