Robots seem to be everywhere these days – in movies, in airports, in food production, and even in factories that make other robots. Robots have many different functions and uses, and as they become easier and cheaper to manufacture, they are also becoming more commonplace in industry. As the demand for robotics increases, robot manufacturers need to keep up, and one basic method of making robotic parts is CNC machining. This article will learn more about robotic standard components and why CNC machining is so important to making robots.
CNC machining is tailor-made for robots
First, CNC machining enables the production of parts with extremely fast lead times. Almost as soon as you have your 3D model ready, you can start making components with a CNC machine. This enables rapid iteration of prototypes and rapid delivery of custom robotic parts for professional applications.
Another advantage of CNC machining is its ability to precisely manufacture parts to specification. This manufacturing precision is especially important for robotics, as dimensional accuracy is key to making high-performance robots. Precision CNC machining keeps tolerances within +/- 0.0002 inches, and the part allows precise and repeatable movements of the robot.
Surface finish is another reason to use CNC machining to produce robotic parts. Interacting parts need to have low friction, and precision CNC machining can produce parts with surface roughness as low as Ra 0.8 μm, or lower through post-processing operations such as polishing. In contrast, die casting (before any finishing) typically produces a surface roughness close to 5µm. Metal 3D printing produces a rougher surface finish.
Finally, the type of material the robot uses is ideal for CNC machining. Robots need to be able to move and lift objects stably, requiring strong, hard materials. These necessary properties are best achieved by machining certain metals and plastics. Additionally, robots are often used for custom or low-volume manufacturing, which makes CNC machining a natural choice for robotic parts.
Types of Robot Parts Made 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. Articulated robots have a single arm with multiple joints, which many people have seen. There’s also the SCARA (Selective Compliance Articulated Robot Arm) robot, which can move things between two parallel planes. SCARA have high vertical stiffness because their movement is horizontal. The joints of the Delta robot are at the bottom, which keeps the arm 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 construction and different applications, but there are generally five main components that make up a robot:
1. Robotic arm
Robotic arms are very different in form and function, so many different parts are used. However, they all have one thing in common, and that is their ability to move or manipulate objects – just like a human arm! Different parts of the robotic arm are even named after our own: the shoulder, elbow and wrist joints rotate and control the movement of each part.
2. End effector
An end effector is an attachment attached to the end of a robotic arm. End effectors allow you to customize the robot’s functionality for different operations without building an entirely new robot. They can be grippers, grippers, vacuum cleaners or suction cups. These end effectors are typically CNC machined components from metal (usually aluminum). One of the components is permanently attached to the end of the robot arm. An actual gripper, suction cup, or other end effector mates with the assembly so it can be controlled by the robotic arm. This setup with two different components makes it easier to swap out 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 robot’s air supply.
Every robot needs motors to drive the movement of the arms and joints. The motor itself has many moving parts, many of which can be CNC machined. Typically, 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 often CNC machined. Shafts can be machined on a lathe to reduce the diameter or on a mill to add features such as keys or slots. Finally, the motor motion can be transmitted to the joints or gears of other parts of the robot by milling, EDM or gear hobbing.
The controller is basically the brain of the robot and it controls the precise movements of the robot. As the robot’s computer, it takes input from sensors and modifies the program that controls the output. This requires a printed circuit board (PCB) to house the electronic components. This PCB can be CNC machined to the desired size and shape before adding the electronic components.
As mentioned above, the sensors receive information about the robot’s surroundings and feed it back to the robot controller. The sensor also requires a PCB, which can be CNC machined. Sometimes these sensors are also housed in CNC machined housings.
Custom jigs and fixtures
While not part of the robot itself, most robotic operations require custom grips and fixtures. You may need a gripper to hold the part while the robot is working on it. You can also use grippers to precisely position parts, which is often required for robots to pick up or put down parts. Because they are usually one-off custom parts, CNC machining is perfect for jigs.
Post time: Apr-08-2022