Nowadays, robots seem to be everywhere-in movies, airports, food production, and even work in factories that make other robots. Robots have many different functions and uses, and as their manufacturing becomes easier and cheaper, they are becoming more and more common in the industry. As the demand for robotics increases, robot manufacturers need to keep up, and a basic method of manufacturing robot parts is CNC machining. This article will learn more about the standard parts of robots and why CNC machining is so important for manufacturing robots.
CNC machining is tailor-made for robots
First of all, CNC machining can produce parts with extremely fast lead times. Almost after you have prepared the 3D model, you can start using CNC machines to make components. This enables rapid iteration of prototypes and rapid delivery of customized robotic parts for professional applications.
Another advantage of CNC machining is that it can accurately manufacture parts that meet specifications. This manufacturing accuracy is especially important for robotics, because dimensional accuracy is the key to manufacturing high-performance robots. Precision CNC machining can keep tolerances within +/-0.0002 inches, and this part allows the robot to perform precise and repeatable movements.
Surface finish is another reason for using CNC machining to produce robotic parts. The interacting parts need to have low friction. Precision CNC machining can produce parts with a surface roughness as low as Ra 0.8μm, or even lower after finishing operations such as polishing. In contrast, die casting (before any finishing) usually produces a surface roughness close to 5μm. Metal 3D printing will produce a rougher surface finish.
Finally, the type of material used by the robot is the ideal material for CNC machining. Robots need to be able to move and lift objects steadily, and they need strong and hard materials. These necessary properties are best achieved by processing certain metals and plastics. In addition, robots are often used for custom or small batch manufacturing, which makes CNC machining a natural choice for robot parts.
Types of robot parts manufactured by CNC machining
With so many possible functions, many different types of robots have evolved. There are several main types of robots that are commonly used. The single arm of an articulated robot has multiple joints, which many people have seen. There is also a SCARA (Selective Compliance Articulated Robot Arm) robot, which can move things between two parallel planes. SCARA has a high vertical stiffness because their movement is horizontal. The joints of the Delta robot are located at the bottom, which keeps the arms light and able to move quickly. Finally, gantry or Cartesian robots have linear actuators that move 90 degrees to each other. Each of these robots has a different structure and different applications, but there are usually five main components that make up the robot.
There are mainly several types of robots commonly used. The single arm of an articulated robot has multiple joints, which many people have seen. There is also a SCARA (Selective Compliant Joint Robot Arm) robot that can move objects between two parallel planes. SCARA has a high vertical stiffness because their movement is horizontal. The joints of the delta robot are located on the base, which keeps the arms light and able to move quickly. Finally, gantry or Cartesian robots have linear actuators that move 90 degrees to each other. Each of these robots has a different structure and different applications, but usually has 5 main components:
1. Robotic arm
Robot arms are very different in form and function, so many different parts are used. However, they have one thing in common, that is, they can move or manipulate objects-this is no different from a human arm! The different parts of the robot arm are even named after our own parts: the shoulder, elbow and wrist joints rotate and control the movement of each part.
2. End effector
The end effector is an accessory attached to the end of the robot arm. The end effector allows you to customize the functions of the robot according to different operations without having to build a brand new robot. They can be grippers, grabbers, vacuum cleaners or suction cups. These end effectors are usually CNC machined parts made of metal (usually aluminum). One of the components is permanently connected to the end of the robot arm. The actual gripper, suction cup or other end effector is matched to this assembly so it can be controlled by the robot arm. This setup with two different components makes it easier to replace different end effectors, so the robot can be adapted to different applications. You can see this in the image below. The bottom disc will be bolted to the robot arm, allowing you to connect the hose that operates the suction cup to the air supply device of the robot. The top and bottom discs are examples of CNC machined parts.
(The end effector involves many CNC machining parts)
Every robot needs a motor to drive the movement of the arms and joints. The motor itself has many moving parts, many of which can be processed by CNC. Generally speaking, the motor uses some kind of machined housing as a power source, and a machined bracket that connects it to the robotic arm. Bearings and shafts are also usually CNC machined. The shaft can be machined on a lathe to reduce the diameter, or it can be machined on a milling machine to add features such as keys or grooves. Finally, milling, EDM or gear hobbing can be used to transfer motor motion to the robot’s joints or other gears.
The controller is basically the brain of the robot, which controls the precise movement of the robot. As the robot's computer, it accepts sensor input and modifies the program that controls the output. This requires a printed circuit board (PCB) to house the electronic components. Before adding electronic components, the PCB can be CNC processed to achieve the required size and shape.
As mentioned above, the sensor receives information about the surrounding environment of the robot and feeds it back to the robot controller. The sensor also needs a PCB, which can be processed by CNC. Sometimes, these sensors are also installed in CNC machined housings.
6.Custom fixtures and fixed devices.
Although not part of the robot itself, most robot operations require Custom fixtures and fixed devices. When the robot is working on the part, you may need a fixture to fix the part. You can also use fixtures to accurately position parts, which are usually necessary for robots to pick up or put down parts. Because they are usually one-off customized parts, CNC machining is very suitable for fixtures.