2,794 stars on GitHub.

The PAROL6 is a high-performance 6-DOF desktop robotic arm designed by Petar Crnjak (Source Robotics) under GPLv3. Its mechanical and control approach mirrors industrial-class arms — closed-loop stepper drives, limit switches on every joint, and an E-stop module — but at a desktop footprint and DIY cost. Source: https://github.com/PCrnjak/PAROL6-Desktop-robot-arm

The repo ships the full STL set organized by joint module (BASE, SHOULDER, UPPER_ARM, ELBOW, FOREARM, WRIST, plus interchangeable gripper attachments — pneumatic, vacuum, mechanical), a complete BOM PDF, step-by-step building instructions, and the PAROL Commander control software. A ROS 2 / MoveIt simulation package and a Python API are maintained alongside.

Specs at a glance:

• 6 degrees of freedom
• ~400mm reach (desktop class)
• Closed-loop stepper drives on every joint with limit switches
• Custom control board (PAROL6) running open firmware
• Optional grippers: parallel mechanical, pneumatic, vacuum

Build resources:

• BOM: https://github.com/PCrnjak/PAROL6-Desktop-robot-arm/tree/main/BOM
• Building instructions: https://github.com/PCrnjak/PAROL6-Desktop-robot-arm/tree/main/Building%20instructions
• Docs site: https://source-robotics.github.io/PAROL-docs/
• Commander software: https://github.com/PCrnjak/PAROL-commander-software
• ROS 2 / MoveIt: https://github.com/PCrnjak/PAROL6-ROS2-MOVEIT
• Hackaday project page: https://hackaday.io/project/191860-parol6-desktop-robotic-arm
• Discord: http://discord.gg/prjUvjmGpZ

License: GPLv3. The PAROL6 is sold preassembled by Source Robotics, but the full design is open for self-sourcing and building.

Printing

The Print All set is the full mechanical build of the PAROL6, byte-verified against the upstream repo's STL/ directory (PCrnjak/PAROL6-Desktop-robot-arm). Print one of each part listed below (PLA/PETG; follow the upstream Building Instructions for orientation, supports, and infill).

Base / electronics enclosure: Electronics_case_v1_1, lid_electronics, fan_cover, J1_bottom_lid, main_base_blocker, connectors_4_alu_profiles

Shoulder (J1/J2): J1_backplate, J1_rotation_shaft, J1_turret_motor_holder, J1_turret_rework_blocker, J1_belt_cover_rework, J1_wires_cover_rework, J2_limit_switch_cover, J2_stopper_block, J2_shaft

Upper arm (J2/J3 drive): J2_bearing_backplate, J2_cover, 42_pulley, 38_pulley_J3, J3_limit_switch_cover, Upper_arm_cover, Upper_arm_wires_cover

Elbow (J3/J4): Elbow_part, Elbow_lid_1, Elbow_lid_2, J4_bearing_backplate, J4_limiter

Forearm / J5 wrist drive: J5_part, J5_belt_lid, J5_electronics_lid, J4_output_pulley, HTD3_48_J5_pulley, wrist

E-stop housing: ESTOP_TOP, ESTOP_BOTTOM

Gripper — choose one (mutually exclusive end-effectors, don't print all):

• Gripper_ARMS — 2-finger mechanical gripper
• Pneumatic_gripper_holder — pneumatic gripper mount
• vacuum_gripper_holder — vacuum/suction mount

Upstream also offers a "horizontal pneumatic" gripper variant (Pneumatic_gripper_holder_horizontal / _custom) you can substitute if that's your setup.

One oversized part not hosted here: Upper_arm.STL (~34 MB, ~677k triangles) exceeds the site's upload limit, so it isn't in the Print Files list. Download it directly from the upstream repo at STL/UPPER_ARM/Upper_arm.STL and print it alongside the parts above — every other structural part of the arm is included.

Not printed (from BOM): 6 × NEMA 17 steppers, the custom PAROL6 control board + TMC5160 drivers, planetary gearboxes, bearings, belts, pulleys (metal), limit switches, E-stop button, power supply, and fasteners.