Annin AR4 (MK3 configuration)

Based on published sources · Not tested by us · Sources checked 2026-09-30

Overview

A six-axis workshop arm with printed or aluminum structure; this review covers MK3 and its matching 6.3-series controls. [S001]

AR4-MK3 offers a choice between printed structural parts and an aluminum structure, but either route involves substantial mechanical and electrical assembly. The manual groups the build into printed covers and spacers, structure, mechanical hardware, six stepper motors with drivers, and electrical components. A gripper adds its own parts list. Even the printed version needs a cut and drilled aluminum J4 tube. [S006]

Official website · Source code

Specifications

Detail	Description
Type	Six-axis articulated arm Reported by source [S001] [S006] · Checked 2026-09-30
Intended users	Experienced makers; Robotics educators Editorial assessment [S001] · Checked 2026-09-30
Assembly	Choose printed or aluminum structure. Printed builds still require a cut/drilled aluminum J4 tube; wiring, bearing fitting and threaded-hole finishing remain necessary. Reported by source [S006] · Checked 2026-09-30
Calibration	Chapter 8 sequences wiring checks, motor direction/travel, limit switches, encoder checks and individual joint offsets. Not reproduced here. Reported by source [S006] · Checked 2026-09-30
Operating system	Windows 10/11 x64 recommended by the control README; Linux/macOS source-build support reported, not reproduced Reported by source [S001] [S006] · Checked 2026-09-30
Computer needed	Desktop or laptop running the AR4 control application Reported by source [S001] [S006] · Checked 2026-09-30

Assembly and use

Keep the MK3 files together

The official downloads page separates MK3, MK4 and MK5. Its MK3 section lists control source 6.3.1, Teensy firmware 6.3 and Nano/Mega sketches 1.3. This profile preserves the GitHub 6.3.1 snapshot, the MK3 version 1.8 manual and the separate MK3 print archive. Newer version numbers elsewhere on that page do not establish compatibility with this configuration. [S002] [S005] [S006] [S007]

There is also a concrete setup discrepancy: the repository README tells readers to enter a Control Software directory, but the inspected archive has AR4.py and requirements.txt at its root, with firmware under Sketches. The README recommends Windows 10/11 x64 and Python 3.11–3.12, and reports source-build support for Linux and macOS. Match the kinematics extension to the host rather than treating the presence of several prebuilt binaries as a tested installation. [S001] [S004]

Assembly includes fitting, wiring and calibration

Budget for tools as well as parts. The manual calls for soldering, drilling and tapping printed holes, bearing fitting, and angle measurement. Chapter 8 proceeds through wiring checks, motor direction and travel, switches and encoders before joint calibration. These steps provide a concrete future test plan; we have not performed them. A current complete delivered cost remains unknown, including the chosen structure, gripper, host computer and tools. [S006]

Read the custom license before planning an offer

The pinned license grants noncommercial software use under its conditions, while its hardware section restricts redistribution and commercial use of the designs. It directs commercial product or service proposals to a separate licensing discussion. Its optional BSD-related badge text should not be read as an ordinary BSD-3-Clause grant. The files are useful for research, but this catalog entry does not establish permission to sell a robot, kit or support bundle. [S003]

Cost

No current, complete configuration-specific build cost has been established for this profile.

Source files and licenses

Available project sources support research coverage; complete build and commercial qualification remain separate.

Layer	Availability / license
mechanical design	available · Annin Robotics custom noncommercial license v1.1 (2025) Printable MK3 files preserved; does not establish complete editable CAD or purchased-component manufacturing sources. License section 2 restricts redistribution and commercial use. [S003] [S006] [S007]
electronics	not found · License not fully assessed Wiring and component BOM documented, but complete manufacturing sources for all purchased controllers/drivers were not established in this review. [S004] [S006]
firmware	available · Annin Robotics custom noncommercial license v1.1 (2025) Custom terms, not ordinary BSD-3-Clause. Commercial licensing and redistribution conditions require separate review. [S003] [S004]
software	available · Annin Robotics custom noncommercial license v1.1 (2025) Custom terms, not ordinary BSD-3-Clause. Commercial licensing and redistribution conditions require separate review. [S003] [S004]
documentation	available · License not fully assessed Public build manual; separate reuse license for this PDF not established. [S006]

This profile covers programmed arm control, without a specified learned policy.

References

Links identify the documentation and revisions used in this profile. Access dates record when each source was retrieved.

S001 · Annin-Robotics / project contributors
Upstream project overview
Accessed 2026-09-30 · README.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S002 · Annin-Robotics / project contributors
Repository revision and release metadata
Accessed 2026-09-30 · cac21f5b33c6b26c1416efca3e7f4dad0b8b0a39
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S003 · Annin-Robotics / project contributors
Repository license
Accessed 2026-09-30 · LICENSE.txt
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S004 · Annin-Robotics / project contributors
Pinned repository artifact inventory
Accessed 2026-09-30 · cac21f5b33c6b26c1416efca3e7f4dad0b8b0a39 archive file inventory
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S005 · Annin-Robotics / project contributors
Official generation-specific downloads
Accessed 2026-09-30 · MK5, MK4 and MK3 download sections
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S006 · Annin-Robotics / project contributors
AR4-MK3 build manual version 1.8
Accessed 2026-09-30 · Overview, assembly tools, printed structure and Chapter 8 startup
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S007 · Annin-Robotics / project contributors
MK3 print archive and preservation receipt
Accessed 2026-09-30 · ZIP member inventory; integrity and SHA-256 verified
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.

Research and review details

Source research only; no installation, physical build or performance test performed. No affiliate links added.

Profile edited 2026-09-30 · Sources checked 2026-09-30 · Next review target 2026-10-30

Combined hardware and software repository revision: cac21f5b33c6 · Activity recorded 2025-11-04 [S002]

Correction guidance · Discussion is not enabled · Profile format 0.5.0-draft.1

Change history

September 29, 2026 — First research profile published.