Auto-assembled, not yet reviewed

PincOpen

Low-cost 1-DoF parallel-finger gripper, derived from Reachy 2, ~25 EUR.

Reproducibility60/100Partial source coverage, unverifiedCADBOMWIREFWBUILDLICREPHow it is computed
PincOpen open-source 1-DoF robot gripper, 3D render from Bottom_Plate.stl
main assembly 3D · Bottom_Plate.stl

About PincOpen

PincOpen is Pollen Robotics' open-source, low-cost parallel gripper inspired by the Reachy 2 Pincette. The project focuses on 3D-printable mechanical parts, replacing the expensive Dynamixel actuator with a Feetech STS3215 servo, and reducing costly standard components while preserving a versatile two-finger grasp. The repository provides STL and STEP CAD, a public Onshape document with configurations, a public BOM link, an assembly PDF, and motor configuration/flash-test instructions.

Licenses

Hardware
CC-BY-SA-4.0
Software
Not published
Docs
CC-BY-SA-4.0

Degrees of freedom

1 DoF gripper 1

Breakdown source

Parallel grippersource

How to build PincOpen

5 steps

Steps marked Motari summary condense the linked source; follow the source for exact instructions. Upstream step marks a step taken from the linked guide.

  1. Print the parts

    Print the 11 unique STL files from cad/stl with the assembly-guide quantities; several finger and linkage parts are used twice. Add the Interface_ARM100 part only if mounting on an SO-ARM100.

    Motari summarygithub.com/pollen-robotics/PincOpen/blob/main/docs/PincOpen_...

  2. Configure the servo

    Set the Feetech STS3215 servo ID and parameters using the LeRobot configure_motor script before assembly.

    Upstream stepgithub.com/pollen-robotics/PincOpen/blob/b4a4c39c680248ea470...

  3. Assemble the mechanism

    Press in the brass plain bearings, fit the 3x16 and 3x24 parallel pins, and bolt the rods and plates together per the assembly PDF to form the parallel-finger linkage.

    Motari summarygithub.com/pollen-robotics/PincOpen/blob/main/docs/PincOpen_...

  4. Fit the fingertips

    Attach the removable tips to the tip supports; swap in application-specific tips as needed.

    Motari summarygithub.com/pollen-robotics/PincOpen/blob/main/docs/PincOpen_...

  5. Wire and test

    Connect the servo through a compatible USB serial/servo interface and run the flash_test.ipynb notebook (pypot / Feetech support) to open and close the gripper.

    Motari summarygithub.com/pollen-robotics/PincOpen/blob/main/docs/PincOpen_...
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.

PincOpen bill of materials

6 rows

Cost to build

€26.46EURsource total
  • standalone gripper: 11 PLA printed parts, Feetech STS3215, servo control board, pins, plain bearings, screws, M3 inserts€26.46source total

In the source currency, as read on 2026-09-30. Not converted, and not checked against current vendor prices: none of these is a Motari-verified checkout total.

PincOpen parts, as the source lists them (read 2026-06-07). Prices are the source's, not checked against vendors.

PincOpen bill of materials
PartQtySpecSourceConfidence
Feetech STS3215 servoLow-cost actuator replacing the expensive Dynamixel motor used by Pincette
1Feetech STS3215 serial servo; configured with ID 6 at 1,000,000 baud
Feetechprice not listedPincOpen README.md lines 55-67 and 78-87
high
Servo controller / USB serial interfaceInterface used to configure and control the Feetech servo
1USB serial port used by lerobot configure_motor.py for Feetech STS3215
Feetech / compatible USB serial controllerprice not listedRead from PincOpen README.md motor configuration lines 78-87 and unread public BOM link lines 63-67
med
3D-printed gripper part set11 unique source STL files, with mirrored/repeated finger and linkage instances per assembly guide
1Bottom/top plates, cam, rods, shells, tips, motor flange from source STL/STEP files
3D print yourself from PincOpen CADprice not listedPincOpen README.md lines 55-76 and cad/stl source files
high
Parallel pins, bearings, screws and insertsGrouped mechanical standard components for joints and assembly
1Pins, bushings/bearings, screws, and heat-set inserts from public BOM/assembly guide
hardware retailprice not listedPincOpen README.md lines 63-67 and assembly guide link lines 89-91
med
Optional SO-ARM100 interface partsOptional mounting/interface configuration for SO-ARM100 project
0Optional interface configuration exposed through Onshape/CAD
3D print yourself from PincOpen CADoptional; price not listedPincOpen README.md lines 67-76
high
Optional camera / Realsense stand partsOptional camera mounting configuration
0Optional camera mounting parts available in CAD configurations
3D print yourself from PincOpen CADoptional; price not listedPincOpen README.md lines 67-76
high

Rows from the source's own parts list 5

README.md@b4a4c39markdown

Source rowQtyPrice and vendorLine
PincOpen low-cost component strategy
source-described component substitutions
PincOpen README / linked resourcesno price listed
L55
PincOpen public BOM overview
source-linked BOM with optional components
PincOpen README / linked resourcesabout 25 EUR stated in README
L63
PincOpen CAD and assembly configurations
source-listed STL/STEP and Onshape resources
PincOpen README / linked resourcesno price listed
L69
PincOpen motor configuration hardware
source-described Feetech servo configuration
PincOpen README / linked resourcesno price listed
L78
PincOpen assembly and flash/test resources
source-linked assembly/test resources
PincOpen README / linked resourcesno price listed
L89

PincOpen source files

9 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.

PincOpen in 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 cad/stl/Bottom_Plate.stl at b4a4c39.

Builds of PincOpen

0 reviewed

No reviewed builds of PincOpen 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 and provenance

Sources

Last push to pollen-robotics/PincOpen: 2026-06-16 (checked 2026-10-01)

How this page was made

Assembled from public sources on 2026-06-04, 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: source-reviewed 2026-06-07.

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

Badge: reproducibility 60/100

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

Not fully met yet: bom evidence (partial), wiring diagram, firmware linked (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