Can Robots be used for CNC Machining?

What materials are used for Robotic parts?

Firstly, parts for robotic applications often have a requirement to be strong, tough and lightweight. Materials such as aluminium have ideal characteristics and can easily be machined using CNC Machining.

Similarly POM (also known as Delrin and Acetal) is commonly used for robotic parts. Easy to machine, it is known for its low friction, high stiffness and superior dimensional stability. As a low-cost plastic, it is also a very economical option.

Can Robots be used for CNC Machining?

CNC machines and robots differ slightly in terms of their core functions. Both are similar in that they can be coded to perform a specific task but the complexity and variation of the particular task is where the key differences come in. CNC machines are highly specialised to manufacture a particular type of part, a set finished product. Robots are generally very versatile and are easily adapted to perform different functions.

Nowadays it is widely acknowledged that, although growing in popularity, CNC Robots will never fully replace CNC Machines. A significant factor that will prevent robots from advancing or becoming more prominent than CNC machines, is the fact that robots tend to be less robust. There are technical challenges when it comes to the hardness of materials that are machined, with CNC machines and their various types (Cutting, drilling, turning) aided with the ability to withstand large amounts of pressure, speed and heavy materials.

Depending on the complexity of the final part required and surface finish required, robotic machining can be seen as a viable alternative. However, it will not replace CNC Machining for 3-4 axis applications. Rather, an addition such as a robotic arm, for example, can help to simplify processes.

It would achieve this by:

• Performing pick and place operations
• Move parts from one machine to another
• Being able to use additional 5th and 6th axes

Essentially, robots can be utilised to replace operator-led processes that increase lead time and costs. The human factor is always a consideration in automated machining & manufacturing, as the more human intervention the increased chance for error and safety concern.

 

How Robots Can Aid CNC machining

Generally speaking, software can help to ensure that the industrial robot will operate efficiently and safely, aiding in the completion of automated tasks. Hand finishing tasks, in particular, can now be completed by CNC robotic systems. Industrial robots with variants of 5 axis milling capabilities, can easily perform polishing operations, a process that could otherwise require hand finishing.

Semi-automated production steps are completed by a CNC machine in some instances, however some steps can only be performed by human or robot operators. Robots can now complete tasks such as:

• Loading raw material into the machine
• Controlling the process
• Unloading finished parts
• Controlling product quality with automated quality inspection

A robotic operator or robotic CNC arm can load any CNC machine, and can control the whole process, unloading the machine after it has finished the task, or checking and packing the final product. A robotic operator can even move parts from one machine to another, and do so safely, precisely and repeatedly to a time efficient standard.

 

Milling

When aiding milling, a robotic arm can be used automatically by communicating with the CNC machine. The positioning accuracy of a robot results in a high quality finished product. One of the biggest time consumers in the milling process involve the positioning of the workpiece, and the changing of the machine tool. An operator is required to do this manually, whereas, a robotic arm can be installed to perform this task automatically by communicating with the CNC machine. The positioning accuracy of utilising a robot results in a high quality finished part.

Welding

An operator can face potential hazards such as gases, fumes, fire and exhaustion from repetitive tasks. By replacing a human operator with a CNC robot welding machine, this will allow the manufacturer to increase positioning accuracy and reach long lasting results. With a reduction in labour costs as well as decreased chance of accident or hazards, it’s understandable why manufacturers may implement robots to assist in the welding process.