compareeHub

BUY A 40,000-DOLLAR INDUSTRIAL ROBOT FOR 200 AND BUILD ITS BRAIN

A six-axis factory robot that sold new for tens of thousands turns up on eBay for a few hundred dollars because the controller cabinet is locked and proprietary, and this project builds the missing brain.

by Excessive Overkill

FULL CAD BOM FIRMWARE DOCS

RoboticsOpen-hardware

difficulty
●●●●●
time
a serious project
license
CERN-OHL-S-2.0 / GPLv3
repo
repo ACTIVE0 stars

WHAT YOU’LL NEED

  • 3D printer + filament — printable parts — files are in the repo
  • Electronic parts — full list with part numbers in the repo BOM
  • Dev board / microcontroller — runs the project firmware
  • Soldering kit + basic tools — one-time buy, serves every future build

Partner

Reach your Pi from anywhere — Remote desktop to the machine running this build — no port forwarding, works right from the browser.Try Getscreen.me
Videos
1

COMPAREE VERDICT

ExcessiveMotion is an open-source motion controller designed to replace the proprietary cabinet that makes scrapped industrial robots worthless. It runs on a Zynq-7000 FPGA plus ARM SoC, with real-time Linux handling high-level control and custom HDL on the FPGA closing the hard real-time servo loops. The backplane accepts modular interface cards for RS-485 and RS-422, the buses most industrial arms actually speak. The creator reverse engineered the servo protocol of a 1.5 ton six-axis arm and demonstrated it running at Open Sauce 2025; in one documented case, a robot that cost around forty thousand dollars new was bought for two hundred and brought back to life. All hardware and software are published, but this is not a turnkey kit. You will be reverse engineering your specific robot's protocol, tuning servo parameters in HDL, and working with high-voltage servo drives that stay charged after power-off. The one thing most likely to go wrong is finding a robot whose servo interface does not match the published examples, requiring you to trace signals and write your own interface layer. This is for people who are comfortable with FPGAs, real-time systems, and the safety discipline industrial machinery demands. If you meet that bar, it is the only open path to owning a real factory arm.

NOT IN THE REPO

  • —Hardware schematics, PCB layouts, and Gerbers are published in the ExcessiveMotion GitHub organization.
  • —FPGA HDL for the real-time servo loops and ARM Linux userspace code are both in the repositories.
  • —Bill of materials exists for the controller board and backplane, including the Zynq-7000 module and interface cards.
  • —There is no assembly manual, step-by-step commissioning guide, or structured documentation on reverse engineering a specific robot model.
  • —The project is under active development; expect to read code and schematics directly.
  • —License is CERN-OHL-S-2.0 for hardware and GPLv3 for software, both permit commercial use with share-alike requirements.

Can I build this?

Printnothing required
BuyZynq-7000 SoM, custom controller PCB (fabricate from published Gerbers), backplane, RS-485/RS-422 interface cards, power supplies, a scrapped industrial robot arm, and the servo drives if not already integrated
ToolsPCB assembly station or assembly service, FPGA toolchain (Vivado), oscilloscope for signal tracing, fenced or guarded work area for a multi-ton arm, high-voltage safety equipment
SkillsFPGA development, real-time embedded Linux, servo drive tuning, reverse engineering serial protocols, and industrial safety discipline; this is a 5/5 difficulty project
Timea serious project — weeks to months depending on your robot model and how much reverse engineering is required
Cost$$$, dominated by the Zynq SoM, PCB fabrication and assembly, and the robot arm itself (a few hundred dollars used, but transport and rigging add cost quickly)
SafetyIndustrial arms move with lethal force and require a fenced or interlocked work area. Servo drives carry high-voltage DC bus capacitors that remain charged after power-off. This is not a desktop project.

This build involves mains voltage — for adults comfortable with electrical work only.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

A desktop 3D printer that prints in full colorPartner · Kickstarter
A desktop 3D printer that prints in full color

HeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.

See how it prints

Videos

Primary project video from the creator's Excessive Overkill channel; details of the protocol reverse engineering and the Open Sauce 2025 demo.

Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Browse the ExcessiveMotion GitHub organization repositories (Hardware schematics, HDL, and firmware are split across multiple repos; start with the controller board and backplane.)
  2. 2.Watch the Excessive Overkill channel project video (Shows the reverse engineering process and the arm running; this is the best overview of what the project actually involves.)
  3. 3.Identify a candidate robot arm(The published interface cards support RS-485 and RS-422; check that your target robot uses one of those buses before buying.)
  4. 4.Set up the FPGA toolchain(Xilinx Vivado is required for building the HDL; the free WebPACK edition covers the Zynq-7000 parts used here.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

Meet Beni, Your First All-Terrain Camera Robot!Partner · Kickstarter
Meet Beni, Your First All-Terrain Camera Robot!
See how it works

KNOWN ISSUES

  • Most scrapped robots have a different servo protocol than the one reverse engineered in the published example; you will be doing your own protocol analysis unless you find the exact same model.
  • The Zynq SoM and PCB fabrication alone will cost several hundred dollars, and that is before the robot, the drives, rigging, and transport.
  • There is no assembly manual or structured commissioning checklist; expect to read schematics and code to understand how the pieces connect.
  • High-voltage servo drive capacitors stay charged after the main power is off; you must discharge them safely before touching anything.
  • A multi-ton robot arm requires a fenced or interlocked work area, not a garage bench; if you do not have that space or cannot build it, the project stops there.
  • Active development means the repositories may change structure or pinout; clone and version-lock before you order PCBs.

Can I use this controller with any industrial robot?

Only if the robot uses RS-485 or RS-422 serial communication to its servo drives and you can reverse engineer or find documentation for its protocol. The published work covers one specific arm model; other robots will require their own interface layer.

Do I need to design my own PCB?

No, the controller board and backplane Gerbers are published. You fabricate and assemble them, or send the files to a PCB assembly service.

What is the Zynq doing that a normal microcontroller cannot?

The FPGA fabric closes the servo loops at hard real-time rates (sub-microsecond jitter) while the ARM cores run Linux for higher-level motion planning and user interface. A microcontroller alone cannot match that timing.

How much does a scrapped industrial robot actually cost?

Anywhere from a couple hundred dollars for a small arm to a few thousand for a large one, but transport, rigging, and any missing drives add cost quickly. The controller itself is several hundred dollars in parts.

Is this safe to run in a home workshop?

Only if you build a proper safety fence or interlock system. Industrial robots move with enough force to kill, and there are no built-in collision limits unless you program them. This is not a collaborative robot.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

The creator reverse engineered one specific robot model and published the protocol — but most scrapped arms will be different. If you have already traced a servo bus on an industrial machine, which brand or model would you try first?

CompareeTEAM6d ago

Practical notes from our verification: the GitHub organization has multiple repositories and no single README that ties them together, so expect to explore the hardware and firmware repos separately. The YouTube video is the best entry point for understanding what the project actually does. There is no structured documentation on commissioning a new robot, and the published interface is specific to the arm model the creator worked with. This is a real open-source motion controller, but it is not plug-and-play; you are effectively co-developing it when you adapt it to a new machine.

Excessive Overkill

The creator runs the Excessive Overkill YouTube channel and reverse engineered a scrapped industrial robot's servo protocol to prove the controller worked. The project was demonstrated at Open Sauce 2025 with a 1.5 ton arm running live.

GitHub

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
GitHub repo