Auto-assembled, not yet reviewed

Actuated UMI Gripper

3D-printable, belt-driven actuated version of the UMI gripper on a Dynamixel servo.

Reproducibility68/100Partial source coverage, unverifiedCADBOMWIREFWBUILDLICREPHow it is computed
Actuated UMI Gripper open-source 1-DoF robot gripper, 3D render from actuated-UMI-v2-assy.step
main assembly 3D · actuated-UMI-v2-assy.step

About Actuated UMI Gripper

The Actuated UMI Gripper is an open-source, 3D-printable parallel-jaw gripper that adds powered actuation to the Universal Manipulation Interface (UMI) hand-held gripper. A single DYNAMIXEL XL430-W250-T servo drives the jaws through a flat belt and twin MGN7C linear rails, with two constant-force springs. The repo provides v1 and v2 STL part sets, STEP assembly files, and an assembly guide, with optional GelSight Mini tactile mounts in v2.

Licenses

Hardware
MIT
Software
MIT
Docs
Not published

Degrees of freedom

1 DoF gripper 1

Breakdown source

Parallel grippersource

How to build Actuated UMI Gripper

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 v1 or v2 STL set (structure, jaws, drive pulley, spring idler, carriage and gripper mounts) in PLA.

    Motari summaryyoutube.com/watch

  2. Install rails and belt

    Install the two 80 mm MGN7C linear rails with carriages and the 300 mm flat belt (5 mm wide, 1 mm thick), following the assembly video.

    Motari summaryyoutube.com/watch

  3. Fit the constant-force springs

    Install the two constant-force springs (0.1 x 8 x 110) with the two printed CF spring idlers, following the assembly video.

    Motari summaryyoutube.com/watch

  4. Mount the Dynamixel servo

    Bolt in the XL430-W250-T servo and connect it through the U2D2 and power hub.

    Motari summaryyoutube.com/watch

  5. Control via Dynamixel API

    Drive open/close through the Dynamixel control API referenced in the README.

    Upstream stepgithub.com/TimSchneider42/dynamixel-api/blob/918c6bba61b89e1...
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.

Actuated UMI Gripper bill of materials

10 rows

Cost to build

The sources do not publish a cost total.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

Actuated UMI Gripper parts, as the source lists them. Prices are the source's, not checked against vendors.

Actuated UMI Gripper bill of materials
PartQtySpecSourceConfidence
DYNAMIXEL XL430-W250-T servosmart actuator for powered jaw motion
1DYNAMIXEL XL430-W250-T
MyBotShop / ROBOTIS channelprice not listedREADME source BOM line 72
high
ROBOTIS DYNAMIXEL U2D2USB-to-Dynamixel interface
1U2D2 interface
MyBotShop / ROBOTIS channelprice not listedREADME source BOM line 73
high
ROBOTIS DYNAMIXEL U2D2 Power HubDynamixel bus power distribution
1U2D2 Power Hub
MyBotShop / ROBOTIS channelprice not listedREADME source BOM line 74
high
Constant Force SpringListed in the README BOM
20.1 x 8 x 110
AliExpress listing linked by the projectprice not listedREADME source BOM line 75
high
Linear rail and carriagejaw guidance rails
280 mm MGN7C
AliExpress listing linked by the projectprice not listedREADME source BOM line 76
high
Flat beltjaw drive belt
15 mm width, 1 mm thickness, 300 mm length
KeilriemenExpressprice not listedREADME source BOM line 77
high
Heat-set insertsthreaded inserts for printed parts
1assorted heat-set insert kit
Amazon listing linked by the projectprice not listedREADME source BOM line 78
high
M3 cylindrical head screws and nutsprimary fasteners
1M3 screw/nut assortment
Amazon listing linked by the projectprice not listedREADME source BOM line 79
high
M2 flat head screwssmall fasteners
1M2 flat-head screw assortment
Amazon listing linked by the projectprice not listedREADME source BOM line 80
high
3D-printed gripper parts setstructure, jaws, idler, pulley, fingers and Franka mount
1PLA/FDM print settings listed per part; TPU fingers defer to UMI guide
3D print yourselfprice not listedREADME print table lines 90-97
high

Rows from the source's own parts list 17

README.md@8e9e957markdown

Source rowQtyPrice and vendorLine
DYNAMIXEL XL430-W250-T
1
MyBotShopmybotshop.deno price listed
L72
ROBOTIS DYNAMIXEL U2D2
1
MyBotShopmybotshop.deno price listed
L73
ROBOTIS DYNAMIXEL U2D2 POWER HUB
1
MyBotShopmybotshop.deno price listed
L74
Constant Force Spring (0.1x8x110)
2
AliExpressde.aliexpress.comno price listed
L75
Linear Rail & Carriage (80mm - MGN7C)
2
AliExpressde.aliexpress.comno price listed
L76
Flat Belt (width 5mm, thickness 1mm, length 300mm)
1
KeilriemenExpresskeilriemenexpress.deno price listed
L77
Heat Sets
1
Amazonamazon.deno price listed
L78
Cylindrical Head Screws & Nuts (M3)
1
Amazonamazon.deno price listed
L79

9 more rows in README.md

Actuated UMI Gripper source files

5 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.

Actuated UMI Gripper in simulation

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

No URDF, MJCF, SDF, USD or Onshape model has been found in the sources.

The 3D specimen on this page is converted from assembly/actuated-UMI-v2-assy.step at 8e9e957.

Builds of Actuated UMI Gripper

0 reviewed

No reviewed builds of Actuated UMI Gripper 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 actuated-umi/actuated-umi-gripper: 2025-05-06 (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 BOM 8e9e957; unpriced.

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

Badge: reproducibility 68/100

Markdown
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HTML
<a href="https://motari.io/r/actuated-umi-gripper"><img src="https://motari.io/api/v1/badge/actuated-umi-gripper" alt="Motari reproducibility score for Actuated UMI Gripper" height="20"></a>

Not fully met yet: wiring diagram, 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