Robot Tech
Plain-language glossary

Robot spec sheets, in plain words.

Robot specifications are full of jargon that makes very different machines look alike. This glossary explains the terms you see most, the main robot types, and how to read a spec sheet without being misled by the headline numbers.

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Core terms

Axis
One joint that can move. A typical industrial arm has six.
Payload
The weight the robot can carry at its wrist, including the tool.
Reach
How far the arm can extend from its base.
Repeatability
How closely the robot returns to the same taught point, time after time.
Accuracy
How closely it reaches a point given as coordinates. Usually worse than repeatability.
End effector
The tool at the end of the arm: a gripper, suction cup, welding torch or camera.
Teach pendant
The handheld controller used to move and program the robot.
Cycle time
How long one complete task takes, from start to ready-for-the-next.

The main robot types

Each type trades flexibility, speed and footprint differently.

TypeShapeBest at
ArticulatedA jointed arm, usually six axesFlexible work: welding, handling, assembly.
SCARAFast arm that moves mostly in a flat planeQuick pick-and-place on a table.
DeltaThree light arms working from aboveVery fast picking of small items from a conveyor.
CartesianStraight-line motion on railsLarge work areas and simple, precise moves.
CollaborativeArm designed for limited force and speedTasks shared with people nearby.

Reading a spec sheet

The headline numbers are measured under the best conditions. Ask these questions instead.

  • What payload can it carry at full reach, not just close to the base?
  • Does the payload figure include the weight of the tool?
  • Is the repeatability figure at full speed and full load?
  • What is the cycle time for a motion like yours?
  • What does the controller need: power, air, space, cooling?

Recent in robot technology

Short summaries of recent reporting, with links to the original articles.

Headlines are quoted as they appear at the source; summaries are our own. Follow the links for the full reporting.