Preparing the published article.
Robot Kinematics Explained: Six Axes, SCARA, Delta and Cartesian
How the mechanical structure decides speed, accuracy and cost.
Four common structures
| Type | Strengths | Typical use |
|---|---|---|
| Six-axis articulated | Reach and orientation flexibility | Welding, assembly, machine tending |
| SCARA | Fast horizontal moves, rigid vertical axis | Electronics assembly, pick and place |
| Delta | Very fast, light payload | Food, packaging, small part sorting |
| Cartesian / gantry | Large workspace, simple control | Large parts, palletising, cutting |
How the choice is usually made
- Payload and required precision come first.
- Then the shape of the working envelope: a cylinder, a sphere or a box.
- Then cycle time: delta and SCARA win on short, repetitive moves.
- Then cost and maintainability at the duty cycle you need.
The accuracy note
Repeatability and accuracy are different claims. Repeatability is how tightly the robot returns to the same point; accuracy is how close that point is to the commanded position. High repeatability with moderate accuracy is normal, and calibration with external measurement fixes most accuracy problems when they matter.