Three Axis Robots

The number of axes a robot has is one of the key factors to consider when selecting an industrial robot. The more axes a robot has the greater the possibilities of movement will be. This is why six-axis robots, like the FANUC Arcmate 120ic, are so common as they have a full range of motion that allows them to automate most types of applications. However, not everyone will benefit or need a six-axis robot. Those automating simple applications may only need a three-axis robot.

Three-axis industrial robots consist of three degrees of freedom, which means they can operate along the X, Y, and Z planes. Unlike higher DOF robots, three-axis robots cannot tilt or rotate making them more rigid than a five-axis FANUC M-410ib/140H or the six-axis Yaskawa Motoman MH24. Three-axis robots are able to automate simple processes in which part orientations and locations do not vary. Most three-axis robots are used for pick and place, part transfer, machine loading, and palletizing.

The majority of three-axis robots consist of Cartesian or SCARA robot types. However, there are some delta robots featuring only three axes as well. The first axis of a three-axis robot is located at the base and operates along the X plane. The first axis controls the horizontal movement of the robotic arm for 180 degrees of motion from center. The first axis is what allows the robot arm to move from right to left and vice versa along the X plane. The second axis allows for movement along both the X and Y planes. It controls the vertical movement of the lower robotic arm. The third axis expands the vertical movement of the robot arm by controlling the up and down motions of the upper robotic arm. Axis three can operate along all three planes.

Advantages of Three-Axis Robots

Since three-axis robots have only three degrees of freedom they can be easier to operate and maintain. Programming a robot with three axes can be easier than programming one with six as there are less axes to coordinate. In addition, a three-axis robot can be easier to maintain since there are three motors instead of six, reducing the robotic components to service. Since three-axis robots are easier to operate and maintain they are ideal for those new to robotic automation.

Another advantage of three-axis robots is they are generally more affordable than those with more degrees of freedom. Typically, the more axes a robot has the more it will cost.

Disadvantages of Three-Axis Robots

One of the main disadvantages of three-axis robots is their limited range of motion. Three-axis robots can accommodate linear movements but their inability to tilt or rotate prevents them from automating more complex applications. Applications requiring movement flexibility will need a FANUC R-2000ic or another six-axis articulated robot.

Since three-axis robots have a limited range of motion they have a narrower scope of applications they can automate. For manufacturing processes that have high turnover, a three-axis robot may not be able to adapt to process changes. However, the ABB 4600-40 and other robots with more axes are capable of automating a wide variety of applications making them incredibly adaptable.

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