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3D PRINT A SIX-AXIS ROBOT ARM WITH 0.1 MM REPEATABILITY - FULL PLANS ARE FREE

A six-axis robot arm with 0.1 mm repeatability that you print yourself, designed like the industrial ones and fully open-source.

by Petar Crnjak

FULL CAD BOM FIRMWARE DOCS

RoboticsWorkshop

Built with3D printing

difficulty
●●●●●
time
several weekends
license
GPL-3.0
repo
repo ACTIVE3,338 stars

WHAT YOU’LL NEED

Videos
1
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COMPAREE VERDICT

PAROL6 is a 3D-printed desktop robot arm designed to behave like a small industrial one, in its mechanics, control software and usability. The official specs: six joints, 400 mm reach, 0.1 mm repeatability, and a payload of 1 kg near the base or 0.5 kg across the full workspace. It uses six NEMA 17 steppers, three bought precision planetary gearboxes and HTD belt reductions, all driven by a single PAROL6 control board with six TMC5160 drivers, connected to your PC over USB. The project is unusually well documented: a full BOM with reference images, a building-instructions PDF, a docs site, the Commander GUI, a Python API and a ROS2/MoveIt simulation. The hardest part is careful mechanical assembly and belt tensioning, and the biggest money decision is the gearboxes: the cheaper MG series works but has more backlash than the EG series in the BOM. The control board is bought from Source Robotics, which also sells complete robots. Read the safety document first: the README warns of lethal voltages, and the project is still under development. Everything is GPLv3.

GOOD TO KNOW

  • —STL files for all printed parts are in the repository (with split versions for small print beds).
  • —Control board firmware is in this repository; the Commander GUI, Python API and ROS2/MoveIt simulation are in linked repositories.
  • —A building-instructions PDF plus a docs site covering specs, the control board, getting started, software and safety.
  • —Bill of materials lists every motor, bearing, fastener and PCB
  • —GPL-3.0 license permits commercial use with source disclosure
  • —Three joints use bought NEMA 17 planetary gearboxes (EG series; cheaper MG series has more backlash), the rest use HTD3M belt reductions.

Parts to buy

7 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • Six NEMA 17 steppers (three sizes)Find
  • Three planetary gearboxes (2× 20:1, 1× 10:1)Find
  • HTD3M belts and pulleysFind
  • BearingsFind
  • PAROL6 control board with six TMC5160 driversFind
  • 24 V 5 A supplyFind
  • FastenersFind

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Can I build this?

PrintAll structural parts, in PETG; split versions of the turret blocker and upper arm exist for small print beds
BuySix NEMA 17 steppers (three sizes), three planetary gearboxes (2× 20:1, 1× 10:1), HTD3M belts and pulleys, bearings, the PAROL6 control board with six TMC5160 drivers, a 24 V 5 A supply, fasteners — full BOM in the repository
ToolsFDM printer (PETG), ST-Link programming adapter, soldering iron and crimpers for cables and connectors, hex keys, multimeter
SkillsHigh: confident 3D printing in PETG, careful mechanical assembly and belt tensioning, extensive connector wiring, flashing the board with an ST-Link, and Python setup for the Commander GUI. A prior robot or CNC build is strongly recommended.
TimeThree to four weekends: one for printing, one for electronics and assembly, one for calibration and tuning, plus debugging
Cost$$$: no total is published. Six steppers, three precision gearboxes, the control board with six TMC5160 drivers, a 24 V 5 A supply, bearings, belts, sensors and grippers add up; the cheaper MG gearboxes cut cost at the expense of backlash.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

PAROL6 v1 - 3D printed 6 axis robot arm / Presentation

Official presentation video from Source Robotics; the README also links a full video-tutorial playlist.

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Gallery

opengraph.githubassets.com
img.youtube.com

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the full assembly guide and check the BOM (Decide between the EG precision gearboxes in the BOM and the cheaper MG series (more backlash) before ordering anything else.)
  2. 2.Download the STL files from the repository's STL folder (All printed parts are in the STL folder; split versions of two large parts exist for small print beds.)
  3. 3.Get the PAROL6 control board and six TMC5160 drivers(The board is sold by Source Robotics; the BOM links tested driver modules.)
  4. 4.Install the PAROL6 Commander GUI and connect the robot over USB(The Commander GUI (separate PAROL-commander-software repo, written in Python) talks to the control board over a USB-B cable; there is also a Python API and a web commander.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • Saving money with MG-series gearboxes instead of the EG precision ones — the README warns they have bigger backlash.
  • The control board is a single PAROL6 board (bought from Source Robotics) with six TMC5160 drivers — use the tested driver modules from the BOM, others are at your own risk.
  • The robot is open-loop: it finds its zero with limit switches and inductive sensors during homing, so mount and adjust the sensors carefully, and keep joint limits correct for your gripper.
  • The wiring is extensive: limit switches, inductive sensors, an e-stop, GX16 and M8 connectors and cable extensions. Follow the BOM reference images for connector types and pin order.
  • Print in PETG as the docs recommend: the steppers can run hot, and PLA softens at a lower temperature. The repo has a PETG printing guide, and split versions of the largest parts for small print beds.
  • The repository assumes you understand robot kinematics and coordinate systems — if 'forward kinematics' is new terminology, start with the documentation and expect a learning curve

Can I skip the planetary gearboxes and still get decent precision?

Not really: three joints are built around planetary gearboxes, and the official 0.1 mm repeatability assumes the EG precision gearboxes from the BOM. The cheaper MG series fits but has more backlash.

Do I need to design my own end effector or is one included?

The BOM includes a pneumatic gripper (MHZ2-16D with a 24 V solenoid valve) and a vacuum suction gripper, and PAROL6 also supports the creator's open-source MSG electric grippers. You can design your own tool too.

What is the actual payload capacity?

Officially 1 kg near the base and 0.5 kg across the full workspace.

Is there ROS support?

Yes — the creator publishes a ROS2/MoveIt simulation repo, alongside the Commander GUI, a Python API and a community web commander.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

PAROL6 is designed to behave like a small industrial arm, with its own commander software and a ROS2/MoveIt simulation. What would you actually use a desktop arm like this for?

CompareeTEAM2mo agoedited

Practical notes from our verification: the repository is well-documented, with the BOM, a building-instructions PDF, a separate docs site, the commander GUI software and the STL files all in or linked from the repo, plus a YouTube video tutorials playlist. The single biggest decision before you order parts is the gearboxes: the BOM specifies EG-series precision planetary gearboxes and notes that the cheaper MG series works but has more backlash. The electronics are not a board you fabricate yourself — the BOM lists the PAROL control board from Source Robotics plus six TMC5160 drivers. Read the safety document first: the README warns of lethal voltages, and the project is marked as still under development. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

Petar Crnjak

Petar Crnjak runs Source Robotics and designed PAROL6 as an open-source desktop arm that behaves like a small industrial robot: planetary gearboxes and belt reductions, a single control board, and proper control software with a GUI, Python API and ROS2 simulation. The project is fully documented, actively maintained, and Source Robotics also sells complete robots and the control board.

GitHub

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DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
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