HapCompass
Based on published sources · Not tested by us ·
License: MIT (repository license) · Details by part
Overview
Fingertip-worn haptic device that rotates one linear resonant actuator with a Dynamixel servo to render 2D directional cues during robot teleoperation; printable parts, an editable source design and a priced BOM are released, but no control code was identified. [S001] [S004] [S005]
HapCompass is a fingertip-worn haptic device from RIPL at the Toyota Technological Institute at Chicago, published at ICRA 2026. It rotates a single linear resonant actuator (LRA) with a servo. An asymmetric drive waveform then produces a pulling sensation in the direction the actuator faces, which the authors use to turn a robot's tactile force changes into 2D directional cues for the operator. [S001] [S006] It is a teleoperation peripheral, not a robot, and suits researchers who already run a teleoperation setup with tactile sensing on the robot side.
Specifications
| Detail | Description |
|---|---|
| Type | Wearable fingertip haptic device: a servo-rotated rotor carrying one linear resonant actuator inside a two-part shell; a teleoperation peripheral, not a robot. Reported by source [S004] [S006] · Checked 2026-10-05 |
| Intended users | Teleoperation and imitation-learning researchers with a tactile-sensing robot setup who can write their own device-control and force-mapping code Editorial assessment [S001] [S005] [S006] · Checked 2026-10-05 |
| Assembly | Six documented mechanical steps (rotor with bearings and inner shells, motor pulley, servo and belt, optional O-rings, belt fitting, shell closure) and four electronic steps (LRA wiring, polarity, amplifier and servo-driver connections). Reported by source [S004] · Checked 2026-10-05 |
| Calibration | Not known |
| Operating system | Not known |
| Computer needed | PC with a speaker output (3.5 mm audio) to drive the LRA through the amplifier and a USB-C connection to the servo driver board. Reported by source [S004] · Checked 2026-10-05 |
3D preview
Preview not available yet. Design-source links are available. A configuration-matched assembly and its file-level reuse scope have not yet been reviewed for a hosted preview.
Model sources
Design-source links are available. A configuration-matched assembly and its file-level reuse scope have not yet been reviewed for a hosted preview.
Assembly and use
What upstream reports
The project page reports three studies: users identifying 4 and 8 cue directions, teleoperated key insertion, USB insertion and spaghetti probing, and a preliminary imitation-learning test. In the last, policies trained on 10 demonstrations collected with directional feedback outperformed policies trained with non-directional controller feedback. [S006] These are the authors' results; nothing was reproduced here.
Building the device
The hardware README lists one Titan Haptics TacHammer DRAKE LFi LRA, a Dynamixel XL330-M077-T servo, an MXL belt, two small bearings, optional O-rings, M2 screws, a PAM8406 audio amplifier board and a Waveshare serial-bus servo driver. Six parts are 3D printed; upstream used a Formlabs Form 3 with grey resin at 0.050 mm layers. [S004] The PC drives the LRA through its 3.5 mm audio output and the amplifier, and commands the servo over USB-C through the driver board; each board needs its own 5 V supply. [S004]
Two cautions come from the README itself. Some fit dimensions are critical to transmitting vibration, and printer or bearing variation may require editing them, but the section on modifying the source design says "Coming soon". The released design was also slightly modified from the paper version to improve stability. [S004]
The software gap
The arXiv abstract says the teleoperation-interface code is released and links the project page. [S007] The pinned repository tree (commit dated 2026-09-29) contains the README, license, project-page assets, one .f3z source design and six STL files, and no code files. The README's software to-do items (device control, tactile mapping, teleoperation) are commented out. [S001] [S005] A builder should expect to write the waveform generation, servo control and force-to-cue mapping from the project-page description. [S006]
Cost
Summing the README's listed prices gives about USD 241, or USD 248 with the optional O-rings. That total includes a four-pack of LRAs at USD 180 and a bearing pack at USD 14. Screws are unpriced and the prices are undated. Printing, power supplies, cables, the PC and the robot are excluded. [S004]
License and unknowns
The repository carries an MIT license (2026, RIPL) whose text refers to "the Software". It is the only license file found; applying it to the CAD and STL files is an inference from its repository-level placement, as there is no separate hardware notice. [S003] [S005] The full repository archive exceeds this catalog's 150 MiB intake limit, mostly because of project-page videos, so the .f3z and STL files were listed but not preserved or checked. [S002] [S005] The catalog makes no safety assessment for body-worn use, and no part was printed, assembled or tested.
Cost
| Version | Price |
|---|---|
| One HapCompass device, purchased parts as listed in hardware/README.md | USD 241.12 [S004] Parts estimate |
US-linked suppliers in the upstream BOM; destination unspecified · Checked 2026-10-05
| Included | Four-pack of TacHammer DRAKE LFi LRAs; Dynamixel XL330-M077-T servo; MXL belt; Ball bearing pack; PAM8406 amplifier board; Waveshare servo driver board; Optional O-ring pack (upper bound only) |
|---|---|
| Not included | Resin printing material and printer; Screws and nuts (unpriced); Two 5 V power supplies, audio and USB-C cables; PC and robot-side tactile sensing; Shipping and taxes not established |
| Stock | Supplier stock and prices not re-quoted; README prices undated. |
| Delivery and tax | Not established. |
Price details
Our sum of the purchase prices listed in the hardware README (LRA 4-pack USD 180, servo 27.49, belt 1.63, bearing pack 14, amplifier 13, servo driver 5); the upper bound adds the optional O-ring pack (6.49). Screws are unpriced. Prices carry no date; pack prices exceed single-unit need.
US-linked suppliers in the upstream BOM; destination unspecified · Checked 2026-10-05 · Quantity 1
Printed parts, power supplies, cables, a PC, a teleoperated robot with tactile sensing, and self-written control code.
Source files and licenses
Mechanical design, BOM and assembly documentation are released under the repository MIT license; control software was not identified. Included as a wearable teleoperation peripheral (category other), not a robot.
| Layer | Availability / license |
|---|---|
| mechanical design | available · MIT (repository license) One .f3z source and six STL files listed; payloads not preserved or geometry-checked. The MIT text refers to "Software"; its application to CAD files rests on the repository-level placement. Purchased LRA, servo and boards are not covered. [S003] [S004] [S005] |
| electronics | not found · License not fully assessed No custom PCB; the device uses purchased amplifier and servo driver boards, with wiring steps documented in the hardware README. [S004] |
| software | not found · License not fully assessed README software to-do items (device control, tactile mapping, teleoperation) are commented out and no code files appear in the pinned tree, although the arXiv abstract says the teleoperation-interface code is released. [S001] [S005] [S007] |
| documentation | available · MIT (repository license) Hardware README with BOM, print settings and assembly; covered by the repository-level MIT file. [S003] [S004] |
Purchased servo and boards run vendor firmware; no custom firmware is part of the design.
Device hardware profile; the paper's imitation-learning policies are outside this configuration and were not identified as released.
Device hardware profile; demonstration data from the paper were not identified as released and are outside this configuration.
References
Links identify the documentation and revisions used in this profile. Access dates record when each source was retrieved.
- S001 · RIPL, Toyota Technological Institute at Chicago / HapCompass authors
HapCompass README
Accessed 2026-10-05 · README.md at main commit snapshotSource notes
Device overview, authors and affiliations, to-do list (software items commented out), hardware pointer.
- S002 · RIPL, Toyota Technological Institute at Chicago / HapCompass authors
Repository revision and acquisition metadata
Accessed 2026-10-05 · 5b11d813b3ed3d2f7e809af9a85c41de93d1e391 (default-branch snapshot; no stable release); GitHub API metadataSource notes
Commit date 2026-09-29; full archive blocked by the 150 MiB intake limit; dated popularity counts.
- S003 · RIPL, Toyota Technological Institute at Chicago / HapCompass authors
Repository license
Accessed 2026-10-05 · LICENSESource notes
MIT License, Copyright (c) 2026 RIPL.
- S004 · RIPL, Toyota Technological Institute at Chicago / HapCompass authors
Hardware documentation and BOM
Accessed 2026-10-05 · hardware/README.mdSource notes
BOM with USD prices, print settings, critical dimensions, mechanical and electronic assembly; source-design instructions "Coming soon".
- S005 · RIPL, Toyota Technological Institute at Chicago / HapCompass authors
Pinned repository file tree
Accessed 2026-10-05 · GitHub git trees API (recursive) at the pinned commitSource notes
Files are README, LICENSE, project-page assets and videos, hardware README, one .f3z source and six STL files; no code files.
- S006 · RIPL, Toyota Technological Institute at Chicago / HapCompass authors
HapCompass project page
Accessed 2026-10-05 · Project page as retrieved 2026-10-05Source notes
Working principle, force-to-feedback mapping, experiment summaries (direction identification, three teleoperation tasks, preliminary imitation learning).
- S007 · Xiangshan Tan, Jingtian Ji, Tianchong Jiang, Pedro Lopes, Matthew R. Walter
HapCompass arXiv abstract (ICRA 2026)
Accessed 2026-10-05 · arXiv abstract page 2603.30042Source notes
Abstract states the design and the teleoperation-interface code are released.
Correction guidance · Discussion is not enabled · Profile format 0.7.0-draft.5
Change history
2026-10-05 — Initial intake from the Growbotics comparison lead; verified against the upstream repository, project page and arXiv abstract.