Three-Axis Robots vs Six-Axis Robots
The range of motion of an industrial robot is determined by the number of axes it is configured with. Each axis of an industrial robot is responsible for an independent motion. The more axes a robot has the greater its range of motion while the fewer axes it has the more limited its motion will be. Most industrial robots used today typically have between three to six axes. Three-axis robots and six-axis robots are on opposite ends of the spectrum in regard to degrees of freedom. Because of this there are some big differences between three-axis and six-axis robots.
MovementSince three-axis robots are built with only three degrees of freedom, they are more limited in their range of motion than six-axis robots. Three-axis robots are capable of moving along the X, Y, and Z axes. With only three degrees of freedom these robots are restricted to simple motions that do not require adjustments to part orientations as they lack the axes needed for EOAT movement.
Six-axis robots have a full six-degrees of freedom for their movement giving them the most similar range of motion to that of a human. Six-axis robots are able to move along the X, Y, and Z axes as well as rotate around each axis. Six-axis robots are able to change part orientations unlike three-axis robots. For instance, the FANUC M-20ia can pick up an object and rotate it a full 360 degrees to change the object’s orientation due to the sixth axis in its wrist. The full range of motion of these articulated robots is one of the reason’s they are the most utilized out of any other robotic axis configuration.
StructureThe robotic structure of three-axis robots typically consists of cartesian, delta, or SCARA robot types. Cartesian and SCARA are the most common structures for three-axis robots since these configurations are designed for simple operations.
Most six-axis robots feature an articulated structure with a single robotic manipulator attached to a rotating base. However, six-axis robots may also consist of delta and collaborative robot types. The FANUC Arcmate 120ic and Motoman MA1440 are both six-axis articulated robots. While the FANUC M-2ia is an example of a six-axis delta robot. The Universal UR10 is a six-axis collaborative robot that features enhanced safety technology for operation directly alongside humans.
ApplicationsDue to the limited motion of three-axis robots they are best for simple applications and more restricted on the types of robotic applications they can perform. Three-axis robots are usually used for automating pick and place, machine loading, part transfer, and palletizing applications in which movements are straightforward and there is no part repositioning involved.
Unlike three-axis robots, six-axis robots are capable of automating just about any production related process regardless of complexity. Their full range of motion makes them the best candidates for automating manual tasks. Six-axis robots may be used to automate assembly, welding, painting, palletizing, material removal, material handling, and inspection processes among many more types of applications. Six-axis robots are incredibly versatile with the ability to automate multiple applications which is why they are considered excellent general-purpose robots. The FANUC R-2000ic can automate material handling, material removal, and spot welding. Six axis robots are the standard when it comes to welding automation.