Computer-Aided Manufacturing: The Superpower That Makes Things Real
Remember when your 5th-grade physics teacher told you about “work done”. That no matter how much you try, it’s not “work done” unless you have a displacement. So basically, there is no point in wasting your energy pushing a wall, unless you’re equipped with superpowers. Same is with your ideas and schematics. If you do not have the aid to implement them in the physical world, you’d better be pushing walls and hope them to move. Here we are going to talk about something that will make you capable of moving a wall.
No, we are not at all here to talk about superpowers, that might exist in some parallel universe but not on earth (as of now). But we do have something that distinguishes us from any form of the living creature, brains. And that is supposedly our superpower. A man’s brain can apparently think of colonizing Mars. Therefore, what we discuss here might not be the best thing that man came up with, but surely it has made the life of manufacturers a lot easy breezy.
Computer-Aided Manufacturing (CAM)
When you need something really produced, not just designed, CAM is the thing you need. Almost all kind of machines requires some sort of control systems to operate. There may be as many kinds of control systems as man wants. For example, manual control, automatic control, computer control or remote control. When it comes to mass production, machines need to iterate precise, speedy and automatic actions continuously.
Since about 1970 manufacturing firms have seen a growing trend towards the use of computers to communicate instructions directly to the manufacturing machines. Therefore, CAM in simple language is the automation of the manufacturing process with the help of software and computer-controlled machinery. A CAM system usually tends to control the production process through different degrees of automation. Because all of the manufacturing processes in a CAM system is computer-controlled, a high degree of precision can be achieved that is not possible with a human interface. The CAM system, for example, sets the toolpath and executes accurate machine operations based on the imported design. Some CAM systems can also bring in additional automation by also keeping track of materials and automating the ordering process, as well as tasks such as tool replacement.
Based on what we’ve understood so far, you need to take care of three aspects for a CAM system to function:
- Software that instructs a machine on how to make any product by generating tool paths.
- Machinery that can turn raw material into a finished product.
- Post Processing that converts tool paths into a language machines can understand.
Since the age of the Industrial Revolution, the manufacturing process has undergone many dramatic changes. Introduction of Computer-Aided Manufacturing is one of those most dramatic changes. Eventually, the manufacturers became capable enough where there are no designs too tough for any capable machinist shop to handle. The technology that evolved from the numerically controlled machines of the 1950s, that were directed by a set of coded instructions contained in a punched paper tape. Today that technology can control virtually any sort of manufacturing process.
Before we can talk further about CAM, we should talk about CAD.
Computer-Aided Manufacturing is commonly linked to Computer-Aided Design (CAD) systems. CAD focuses on the design of a product or a part. How is it supposed to look, how it should function? CAM focuses on how to make it. So, therefore, CAD without CAM is like pushing that wall, no work achieved. Every engineering process commences in the world of CAD. Engineers can make either a 2D or 3D drawing, whether that’s as complex as the electronics in a circuit board, or as lame as the design of the bathroom faucet. Hence, CAD design is called a model and contains a set of physical properties that will be used by a CAM system.
When a CAD completes its designing, it’s then fed into CAM. This is traditionally done by exporting a CAD file and then importing it into CAM software. Once your CAD model is imported into CAM, the software starts preparing the model for machining. Machining is the controlled process of transforming raw material into a defined shape through actions like cutting, drilling, or boring.
CAM software prepares a model for machining by working through several actions, including:
- Checking for any geometrical errors impacting the manufacturing process.
- Creating a toolpath for the model, it is basically a set of coordinates the machine will follow during the machining process.
- Setting any required machine parameters including cutting speed, voltage, cut/pierce height
- Configuring nesting where the CAM system will decide the best orientation for a part to maximize machining efficiency.
Computer-Aided Manufacturing and Computer-aided design together facilitate mass customization. Without CAM, and the CAD process, customization would be a time-consuming, manual and costly process.
No idea about what that is? And how is it better with CAD/CAM?
It is the process of creating small batches of products that are custom designed to suit each particular client. CAD software makes customization heck-free and allows rapid design changes. The automatic controls of the CAM system make it possible to adjust the machinery automatically for each different order.
Therefore, everything seems pretty impressive until now. Once CAD prepares the model for machining, simply all of that information gets fed into the machine to physically produce that very part. But how do you think is the machine instructed? Like, “Hey machine this is the 3-D schematic of my circuit board, please present me with its real-world version.” No right, we can’t just give a machine a bunch of instructions in English, we need to speak the machine’s language. To do this we convert all of our machining information to a language called G-code. This is the set of instructions that controls a machine’s actions including speed, feed rate, coolants, etc.
G-code is easy to read once you understand the format. An example looks like this:
G01 X1 Y1 F20 T01 S500
This breaks down from left to right as:
- G01indicates a linear move, based on coordinates X1 and Y1.
- F20sets a feed rate, which is the distance the machine travels in one spindle revolution.
- T01tells the machine to use Tool 1, and S500 sets the spindle speed.
Until now we kept saying machines, machining, fed into machines and blah blah. But what are these machines? And how do they work with G-Code?
A variety of Computer Numerical Control (CNC) machines are being used to produce engineered parts. The process of programming a CNC machine to perform specific actions is called CNC machining.
Earlier in the past when CNC was not in action, manufacturing centers were operated manually by Machinists. Computer and automation are kind of ‘bffs’ as usually called by millennials. Wherever a computer goes, automation follows and here it was no exception. These days the only human intervention required for running a CNC machine is loading a program, inserting raw material, and then unloading a finished product.
Before we end this topic, let’s talk about CAM and man.
Back in the days of manual machining, being a Machinist was a something really huge that took years of training to perfect. A Machinist had everything on his head– read blueprints, know which tools to use, define feeds and speeds for specific materials, and carefully cut apart by hand. It wasn’t just about being precise. Being a Machinist was, and still is, a matter of both art and science. Skills that earlier took years and years to master can now be conquered in a fraction of the time. New machines and CAM software have given us more control than ever to design and make better and more innovative products.
Even though CAM is making a world of automatic manufacturing, the specter of robots completely replacing humans is still a delusion. Robotic arms and machines etc though are commonly used in manufacturing, but they still require human workers. The job description of those workers change, however.
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