Industrial Robot Arms Explained

There are four main types of industrial robot arm — articulated, SCARA, delta and Cartesian — and each has a distinct sweet spot. This guide explains how they differ, what the specs mean, and how to choose for your application.

The four types of industrial robot

Type Axes Best for Speed (typical) Payload range Key limitation
Articulated (6-axis)5–7Welding, tending, general handlingModerate3–2,300 kgComplex programming; slower in straight-line tasks
SCARA4Horizontal pick-and-place, assembly, insertionVery fast (40–100 ppm)1–20 kgCannot reach around obstacles; limited vertical range
Delta (parallel)3–4High-speed pick-and-place (food, pharma, electronics)Extremely fast (100–300 ppm)0.5–15 kgShallow workspace; low payload; no wrist rotation (3-axis)
Cartesian (Gantry)3Dispensing, large-format pick-and-place, CNC loadingModerateUp to 500+ kgNo angular reach; cannot work around obstacles

Repeatability vs accuracy: what actually matters for manufacturing

Repeatability is how consistently the robot returns to a taught position. Accuracy is how close it gets to an absolute coordinate in space. For robot programming by teaching (jogging to a position and recording it), repeatability is what matters — typically ±0.01–0.05 mm for industrial robots, ±0.02–0.1 mm for cobots.

Absolute accuracy matters when you generate robot paths offline from CAD models and upload them without teaching, or when multiple robots need to hit the same absolute coordinates. Industrial robots achieve ±0.5–2 mm absolute accuracy without calibration; with laser calibration this drops to ±0.1–0.3 mm.

Buying a used industrial robot: what to check

A used articulated robot in good condition (low cycle count, maintained, with working controller) can cost 20–40% of new. Key risks: worn joints (check axis-by-axis repeatability with a ballbar or dial gauge), damaged wiring harnesses, end-of-life controllers with no software support, and missing safety documentation. Always request the maintenance history and run a full test cycle under load before purchase. See the full checklist for SCARA robots and the six-axis market.

In-depth guides by robot type

Delta Robot: Applications, Speed and Limitations

How parallel-linkage delta robots achieve 300 picks per minute, and which applications they are — and aren't — suited for.

SCARA Robot: Uses, Specs and When to Choose One

Four-axis SCARA speed, assembly insertion accuracy, price ranges, and where SCARAs beat both articulated robots and cobots.

Cartesian Robot Guide: Gantry Systems Explained

Three-axis linear robots: when Cartesian beats articulated, large-format dispensing, and how to size the axes.

6-Axis Robot: What the Joints Do and When You Need Them All

Why six axes, when four is enough, and real payload vs reach trade-offs for the most common robot configuration.

Industrial Robot Products by Brand

Full specs, application guides, and competitive comparisons for the most widely deployed industrial robot models.

FANUC LR Mate 200iD

The world's best-selling small industrial robot: 7 kg, ±0.02 mm, IP67 wash-down, machine tending vs cobot comparison.

FANUC M-Series Delta Robots

M-1iA, M-2iA and M-3iA: up to 150 picks/min, integrated iRVision, IP69K food-grade variants, multi-robot coordination.

ABB IRB 360 FlexPicker

1–8 kg delta robot for food, pharma and electronics: 200 picks/min benchmark, PickMaster conveyor tracking, IP69K.

Epson SCARA Series

LS belt-drive and RS direct-drive SCARA robots: ±0.005 mm repeatability, free RC+ software, 8 robots per controller.

Frequently asked questions

What is the difference between a 6-axis and a 4-axis robot?
A 4-axis (SCARA) robot has horizontal rigidity and is extremely fast for flat pick-and-place. A 6-axis articulated robot can reach any orientation in space — ideal for welding, complex tending paths, or working around obstacles — but is generally slower for simple horizontal motions and more complex to program.
How fast is a delta robot in picks per minute?
A delta robot (parallel kinematic robot) typically achieves 100–300 picks per minute for small, lightweight parts (up to ~2 kg), depending on move distance and object size. FANUC's M-1iA delta series is rated up to 200 cycles per minute. Compare to a SCARA at 40–100 picks per minute and an articulated robot at 30–60 picks per minute for similar tasks.
What is a typical industrial robot lifespan?
Well-maintained industrial robots typically operate for 80,000–150,000 hours before major joint overhaul. At three-shift, 24/7 operation (8,760 hours/year) that is 9–17 years. Robots in moderate-duty applications (single-shift, lighter payloads) often run 20+ years with periodic grease changes and joint rebuilds. Controller hardware and software support typically limits practical life to 15 years.
Can I retrofit an old robot with a new controller?
Sometimes. Third-party controller providers (e.g. Wandelbots, Energid, ROS-Industrial integrators) can replace proprietary controllers on some robot arms, extending hardware life when the original OEM no longer supports the controller. This is economical for mechanically sound robots with outdated controllers but adds integration complexity and may void remaining warranty.

Sources

  1. FANUC M-1iA delta robot datasheet, fanucamerica.com, accessed September 2026
  2. Epson SCARA RS series specifications, epsonrobots.com, accessed September 2026
  3. ISO 9283:1998 — Manipulating industrial robots — Performance criteria and related test methods
  4. Internation Federation of Robotics, World Robotics 2025 report, IFR Statistical Department