Stringman, an open-source cable robot, reaches a whole room with four motors

Neufangled Robotics presents Stringman, a cable-driven gripper robot built to work across a whole room. Its pitch starts from a blunt premise: "In robotics, price is basically actuator count." Stringman reaches an entire room with four motors, hanging its gripper from lines anchored in the ceiling corners. Working from above, the makers say, it reaches floors too cluttered for any wheeled or legged robot. Because all motors share the lifting force, payload capacity scales with their combined torque rather than a single actuator's, and it peaks near the center of the room, where the lines share the load most evenly.

The headline comparison is cost-efficiency. The page claims "roughly 500× the work area volume per dollar, at comparable 2 kg payload." The footnote defines the baseline: a 0.75 m serial arm using the same DM-H6215 1 N·m direct drive actuators at rated torque, ignoring the weight of its own links. The Stringman figure is for a 7 × 7 × 3 m room at the 28 N line tension limit, net of its 638 g gripper and marker. The page also argues that removing the battery helps: Stringman is powered from the wall, so it is always ready for work, and it avoids the weight of carrying its own power supply. The gripper's power runs through one of the support cables, a two-conductor FEP jacketed twisted pair with a tensile strength of 50 N.

The project is open source and OSHWA certified; the mechanical CAD, the PCBs and the control software are all published. Anchors and eyelets go in the room's corners near the ceiling, secured to wall studs with wood screws or to columns with ratchet straps. They can be detached without tools, leaving a relatively small white cleat on the wall, and the makers suggest printing an anchor mockup in white PLA to preview the look in a corner. The gripper hangs below the pivot point so it can reach the floor next to beds and tables. That linkage could allow unconstrained motion, so Stringman uses active swing cancellation algorithms to counteract momentum, without adding any extra motors. The gripper itself has two fingers and a wrist; the makers say their household tests showed more layers of grip tape were a better return than more articulated fingers.

On the software side, the page says Stringman works with LeRobot, including Pi.05, JEPA, Multitask DiT and others. Training data for new behaviors can be collected from the UI, and as few as 50 episodes can be enough for certain models like DiT to learn a behavior. Default models handle automatic grasping and target and destination selection. For tidying, owners place clip-on fiducial tags on a laundry bin, toy box or trash can; the robot maps these destinations visually, and individual items can be marked off-limits. Networks trained on the robot have learned that the word "toybox" refers to the tag. The same tags can mark source and destination points for ferry jobs, such as moving items from one robot arm to another. A Python API and an MCP server are provided for agents. Datasets are public on Hugging Face, and there is a controller-in-the-loop MuJoCo sim.

On privacy, Stringman can run air gapped on a local Wi-Fi network: the UI is served locally, AI models run on the owner's hardware, and no data leaves the network. Remote operation is off by default. Binding the robot to an account via neufangled.com/playroom lets the owner, or anyone they share access with, operate it from anywhere, and access can be revoked at any time. The page says Neufangled Robotics does not store any of the information forwarded through its servers, and an owner can return to LAN-only mode whenever they like.

There are installation limits. When line tension reaches 28 newtons (about the weight of a backpack), all motors relax and the lines can be pulled loose; since the lines are overhead most of the time, collisions with people are described as uncommon. A ceiling fan can be avoided by mounting anchors at or below blade level, and the work area can be shrunk to exclude low light fixtures off to the side. But if the center of the room contains low hanging objects, Stringman cannot be installed in that room. The original prototype was built in a room with a ceiling fan and still runs there.

Key facts

Stringman reaches an entire room with four motors, hanging its gripper from lines anchored near the ceiling corners.
The makers claim roughly 500× the work area volume per dollar at a comparable 2 kg payload, measured against a 0.75 m serial arm with the same DM-H6215 1 N·m actuators.
The Stringman figure is for a 7 × 7 × 3 m room at the 28 N line tension limit, net of its 638 g gripper and marker.
Mechanical CAD, PCBs and control software are published, and the project is OSHWA certified; datasets are public on Hugging Face and it works with LeRobot.
It can run fully air gapped on a local network; remote operation through the maker's relay is off by default. It cannot be installed in a room with low hanging objects at the center.

Why it matters

The design bets that cost in robotics follows actuator count, and that a cable layout can cover a room volume with four motors where mobile robots need more hardware. The maker's claim is roughly 500× the work area volume per dollar at a comparable 2 kg payload. Because the CAD, PCBs and software are published and the project is OSHWA certified, others can inspect and build on it. The page also frames the robot as an unusual test body for cross-embodiment work, saying a model operating a vastly different body type is a stronger result than moving it between two bimanual robots.

Who it affects

The page targets three groups. Home users with cluttered floors get a robot that works from above and tidies toward tagged destinations such as a laundry bin or toy box. Home labs can use it to carry parts between workcells or from one robot arm to another. Classrooms can use it to teach inverse kinematics, telemetry and imitation learning; the page says that with walls and a MacBook you are more than halfway there. Rooms with low hanging objects at the center are excluded.

How to use it

Mount cleats near the ceiling corners, on wall studs with wood screws or on columns with ratchet straps; the page links picture and video guides. Anchors detach without tools. Tags on destinations tell the robot where things go, and individual items can be marked off-limits. New behaviors can be trained by collecting episodes from the UI; as few as 50 can be enough for certain models like DiT. Control works through LeRobot with Pi.05, JEPA, Multitask DiT and others, and a Python API and MCP server are available for agents. The robot can stay on a local Wi-Fi network, or be bound to an account at neufangled.com/playroom for remote access. The page offers printable anchor mockups and swappable faceplates (STL or Bambu 3MF files).

How solid is it

Every figure comes from the maker's own product page. The 500× comparison rests on a footnote: a 0.75 m serial arm with DM-H6215 1 N·m actuators at rated torque, ignoring its own link weight, against Stringman in a 7 × 7 × 3 m room at the 28 N tension limit, net of the 638 g gripper and marker. The source gives no independent test or third-party verification of the payload or 500× figures. The $800 price in the submission title does not appear in the source text, and no release date, bill of materials or cost breakdown is given. The OSHWA certification and published design files are stated on the page.

Risks and caveats

Installation is the main limit: if the center of the room has low hanging objects, Stringman cannot be installed there. Fans and side-mounted light fixtures can be worked around. Lines pull loose at 28 N, which is also the limit behind the payload figure, so the payload is tied to that tension ceiling. The gripper has only two fingers and a wrist, a deliberate trade for low weight and cost. Remote use means sending robot information through the maker's servers; the maker says it stores none of it, and a LAN-only mode is always available. No safety certification is mentioned in the source.

“In robotics, price is basically actuator count.”

— Neufangled Robotics, Stringman product page