Robot Arm (Manipulator)
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An articulated mechanical arm with multiple powered joints, designed to position a tool — gripper, welder, spray nozzle — in 3D space.
The concept concept: An articulated mechanical arm with multiple powered joints,
Difficulty 3/5 · ClassroomA **robot arm** (formally: manipulator) is an articulated chain of rigid links connected by powered joints, ending in an **end-effector** — gripper, vacuum cup, welder, paint nozzle. The arm positions the end-effector somewhere in 3D space. That's it. Everything else is detail.
💡 Think of it like…
Think of it like a household object that does the same job — the underlying idea is the same, just adapted for robots.
Why it matters
Without robot arm (manipulator), many concept systems in robotics simply couldn't work.
A robot arm (formally: manipulator) is an articulated chain of rigid links connected by powered joints, ending in an end-effector — gripper, vacuum cup, welder, paint nozzle. The arm positions the end-effector somewhere in 3D space. That's it. Everything else is detail.
Degrees of freedom
The number of independently-controllable joints. To reach any pose (position + orientation) in 3D space you need 6 DOF. Most industrial arms are 6 DOF; some are 7 (extra elbow joint for dexterity in cluttered spaces) or 4 (SCARA arms — fast, top-down assembly).
Workspace
The set of points the end-effector can reach. Drawing the workspace is one of the first things you do when designing an arm — it tells you what tasks are physically possible.
Payload
The maximum weight the arm can lift at full extension. UR5e is 5kg. The same arm folded close to the base can lift much more — payload is rated at the worst case.
The arm family tree
- SCARA (Selective Compliance Assembly Robot Arm) — 4-DOF, fast, top-down, used in electronics assembly.
- 6-DOF articulated — the classic — Universal Robots, KUKA, ABB, Systemantics SyMo.
- Cartesian / gantry — translation-only joints. Slow but precise, big workspace. Plotters, 3D printers, CNC.
- Delta — 3 parallel arms, ultra-fast pick-and-place (food packaging).
- Soft / continuum — research-grade, biologically inspired.
Collaborative vs industrial
- Industrial (KUKA, FANUC) — fast, strong, dangerous. Operate behind cages.
- Collaborative (Universal Robots, Franka, Systemantics) — force-limited, designed to work alongside humans. Slower but safer. Driving the explosion of arms in SMEs.
In India
- Systemantics (Bangalore) — designs and manufactures 6-DOF collaborative arms. India's most advanced indigenous manipulator company.
- Bharat Forge KSSL (Pune) — heavy-industrial-arm manufacturing.
- TAL Manufacturing (Tata, Pune) — TAL BRABO industrial arm.
- CMR Surgical's India arm — research on surgical manipulators.
A 6-DOF UR5-class arm costs ₹15-25 lakh. A Systemantics SyMo costs ₹8-15 lakh — increasingly the choice for Indian SME automation.
See it in action
Open the 3D Robot Explorer and toggle to the UR5 arm. Drag the joint sliders — watch the end-effector trace out the workspace. The math behind it is in the [[kinematics]] entry.
Related concepts
[[kinematics]] · [[inverse-kinematics]] · [[servo-motor]] · [[mobile-robot]] · [[ros2]]
Ask R2 Co-pilot anything you didn't understand about Robot Arm (Manipulator). It'll explain it plainly.
Learn this in the Academy
🔥F-02: Robot Manipulation with MoveIt2
Hands-on lesson · Forge track
Keep going
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Inverse kinematics is the math a robot uses to figure out which joint angles will put its hand exactly where y…
ConceptKinematics
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ConceptMobile robot
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Last updated · 2026-05-21
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