What is CNC Machining?

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CNC machining isn’t difficult to understand, and with a brief explanation and some background knowledge, anyone can make sense of the basic processes this type of manufacturing uses. If you’re like most people, however, you probably don’t know much about CNC machining because it isn’t something you encounter very often. It’s likely the majority of people who know a bit about CNC machining only do so because it’s part of their industry or because they’ve needed to interact with it in some way.

Are you looking to purchase or use fabricated metal, plastic, wood or foam? If so, it likely won’t be long before you start encountering concepts like CNC machining. Once you do, it can be difficult to discern whether or not this type of metal fabricating is right for your purposes without first possessing a basic understanding of what CNC machining is, how CNC machines work and why some businesses choose it over comparable options.

We want to help give you the background you need to make an informed decision when it comes to purchasing the fabricated metal that will be right for you. That’s why today, we’ve compiled this guide to the basics of CNC machining. By perusing this guide, we hope you’ll be ready to make the decision you need regarding your next step forward.

The Basics of CNC Machining

CNC machining is a manufacturing process where precisely programmed computer software controls the movements of factory equipment, tools and machinery. The acronym stands for “computer numerical control,” which references the fact that carefully coded computer commands control the entire machining process. CNC machine experts use these commands to operate factory machines, which in turn execute these commands to manufacture a completed product.

The primary process CNC machining improves upon is the process whereby operators would manually control every movement of the factory tools. An operator would need to stand at each factory station, physically operating the lathes and mills to create the desired final product. With CNC machining, however, these operators are no longer needed, creating a process that’s safer, faster, more efficient and often more effective.

CNC machining is compatible with an incredible range of tools. From plasma cutters and lathes to lasers and mills, machinists can dictate the movements of these and many more devices, all down to the smallest and most precise movements, to create uniform finished products.

How Do CNC Machines Work?

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CNC machining is a complex process that breaks down into several different steps, all of which are crucial to achieving the finished product. If the factory or machine shop in question neglects any of these steps, the process will not work. To get a better understanding of how this process works, let’s examine it from start to finish.

1. Designing the Model

The very first step in the process of CNC machine programming is creating a model that will be the basis for the finished product. Engineers and designers will complete this process using software such as a computer-aided design (CAD) program, where they can create, manipulate and render a 3D model. Within the confines of this software program, they will create the design, tweak it, adjust and otherwise shape it until they confirm it is exactly the design they want.

Because CNC machining will eventually build this design, the software will typically not allow for the creation of anything that is beyond the limits of the machines. In other words, if an engineer tried to design anything the machines wouldn’t be capable of creating, the software would not allow it, notifying the designer that their model was unfeasible.

Once the design is complete, approved and shown to be compatible with the CNC machining technology, it’s time to move on to the next step.

2. Converting the Design

Now that the design is ready to go, the engineers need to translate it into a language the CNC machines can understand and interpret. To do this, workers will run the CAD model through a program that extracts the precise geometry of the design and converts it into a code that is compatible with the machines the engineers will then use to create the full-sized version of the design.

This extracted code is a combination of computer languages that work together to control different machine functions. Most notably, these include the programming languages commonly known as G-codes and M-codes. The G-code, also known as the geometric code, controls the bulk of the machines’ movements, including when, where and how they move as well as when they turn on and off and what paths they take to reach a specific location. The M-code, which stands for miscellaneous function and controls auxiliary functions, works to control additional movements like the replacement and removal of the machine covers at the beginning and end of the process.

After extracting this CNC program from the original design, the machine operators will load this code into the CNC machine.

3. Setting up the Machines

Before the machine operators can initiate the program and let the physical process begin, they’ll need to make sure the machines are ready and in position. That means they’ll need to add or remove all the proper and necessary attachments, move machine components into place and attach extra pieces such as drill bits and end mills. They’ll also need to perform safety checks to make sure no one and nothing is in the way of the machines.

Once the operators are sure everything is ready to work and there are no obstructions anywhere in the way, it’s time for the final step to begin.

4. Executing the Program

By initiating the program, the entire machine will begin to move. The CNC program extracted from the CAD design acts like a set of instructions, telling each machine exactly when to move and where to work to create the desired finished product.

Typically, this process involves a solid piece of material, such as a sheet of metal. The various tools and machines then work to carve, drill and cut away at this piece of metal, working to shape it into the design as dictated by the digital instructions they’re receiving from the CNC program.

What Pieces of Equipment Use CNC Programming?

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We’ve already mentioned that CNC coding can control a wide range of various tools and pieces of machinery. But how far does that range extend? How many types of CNC machines are there, and what are they? It’s challenging to write a comprehensive list, as different CNC machine shops will use different tools depending on the types of products.

This list, however, includes the most common tools many CNC machining sites use.

  • Milling machines: These can either be purpose-built with the intent of using CNC machining, or retrofitted out of ordinary milling machines to be compatible with CNC technology. Either way, they perform the same function of using rotary cutters to remove sections of raw material.

  • Lathes: Lathes can also be designed specifically for CNC machining or can be retrofitted after the fact to be compatible with the new technology. In either case, their function remains the same as they cut, drill, sand and turn the material symmetrically.

  • Routers: These tools are exclusively for CNC machining and have no other function. You won’t likely find them used in any other industrial setting, as they’re incompatible with anything but CNC technology. Their purpose is to help produce parts with large dimensions smaller tools couldn’t handle, typically by cutting away at materials such as wood, metal or plastic.

  • Plasma cutters: CNC plasma cutters are those designed with the express intention of usage with CNC machining. They are quite similar in setup to CNC routers, but they don’t require quite such a heavy-duty makeup, as they don’t need to drag around a heavy tool. Instead, they use a plasma torch to cut two-dimensional shapes into sheet metal.

  • Laser cutters: Laser cutters exist outside the realm of CNC machining, but the ones we’re discussing here are those designed for exclusive use with CNC programming. They work similarly to a plasma cutter, except that they use a powerful laser to perform the cutting work, and can cut through metal, wood or plastic, depending on the exact strength of the laser used. These are a particularly essential component, so much so that APX York Sheet Metal has three of these tools used among our sister companies and us.

  • Pick-and-place machines: Just as the name suggests, these machines’ job is to pick components up, move them to another location and set them down again. They do this by using a vacuum to pick the piece up, before shifting and setting it down again in its new location. This ability to move and place tiny components is particularly crucial when building devices with a circuit board component.

Specific CNC machining services may use more components than this, or they may have fewer. It depends on what material the machine shop is working with, what they’re looking to do with the material and what type of processes will be necessary to achieve this. Nevertheless, this list represents a few of the most broadly used tools across the industry.

What Are the Benefits of Using CNC Machining Equipment?

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In the grand scheme of the history of machining and industrial production, CNC machining is a relatively new development. It has existed since the 1940s when machinists would retrofit pre-existing machines to fit with the new technology. Today, most CNC machining involves machines that have been specifically designed to complement the computer technology.

Of course, if CNC machining is still relatively new, that leads us to some questions. What techniques did machinists use before CNC machining? More importantly, what makes CNC machining superior to these older methods, and what benefits does CNC machining offer that other methods do not?

1. It’s Safer

Older methods of machine operations required operators to stand at the machines themselves, physically operating them and moving the various components around. By extension, this required human operators to work next to dangerously sharp moving parts. This proximity naturally meant the risk for accidents was higher.

CNC machining eliminates this danger, as human operators do not have to be near the tools as they work. All they need to do is operate the computer controls that set the machines in motion, then watch a safe distance as the machines carry out their predetermined code to create the desired product. The risk of injury is slim to nonexistent.

2. It’s More Precise

No matter how skilled machine operators are, they’re still human, and that means that their work will likely not be as uniform and precise as that of a machine operating according to strict instructions. A human operator might produce 100 items that are all nearly identical, but close inspection will almost certainly reveal slight differences between the different objects.

A machine, on the other hand, will produce the same item every time. The only reason there might be differences between products is if there is an error in the programming or if something goes wrong with the machines. If everything goes according to plan, however, those 100 items will all be perfect copies of each other — completely uniform and exactly matching.

3. It’s Faster

When human operators are manually performing every step of the process, it takes time. CNC machining, on the other hand, allows for multiple parts to be moving at the same time and many operations to be carrying on in the same moment. Everything is automated, with no need for hesitation between one step and the next. The result is an operation that’s far faster and far more efficient than any other type of machining production.

Choose APX York Sheet Metal for Your CNC Machining Needs

CNC machining can be useful for a whole host of different industries, such as aerospace and communications. Are you part of an industry that frequently makes use of CNC machining? Are you looking for a machine shop to handle your CNC machining needs? We invite you to come and visit us here at APX York Sheet Metal.

We’re a custom sheet metal fabrication shop based out of York, Penn., where we’ve been family-owned for the past 71 years. Not only that, but some of our team members also have more than 25 years of experience in the industry, meaning we have the background and in-depth industry knowledge to provide you with the services you’re looking for. We pair this industry expertise with personalized customer service, quick turnaround times and a one-stop-shop experience where everything gets completed in-house for a CNC machining experience that gives you the individual attention you deserve.

Are you ready to get started discussing your next CNC machining project? Contact us to get the conversation started and to request a free quote for your project.

Choosing Sheet Metal Thickness

Custom sheet metal fabrication is a precise art and science. Creating the sheet metal that goes into your design revolves around bonding, forming, cutting and assembling pieces that fit together as an object or machine. At APX York Sheet Metal, we perform custom sheet metal fabrication to meet the demands of projects both large and small.

We serve a variety of industries. So how do we go about selecting the proper thickness for sheet metal projects?

How to Decide Sheet Metal Thickness: The Bigger Picture

Sheet metal can be crafted into just about any object imaginable. Using custom sheet metal technology, our experts mold tailor-made pieces to suit companies across the Mid-Atlantic region. We are able to create a number of custom projects for businesses thanks to sheet metal's pliability.

What do we mean? Sheet metal is available in a variety of thicknesses to match what our experts are trying to build. One of the most important parts of custom sheet metal fabrication is selecting the correct gauge for the job.

Sheet Metal Qualities

Selecting sheet metal thickness requires familiarity with material gauges. With custom sheet metal fabrication, always note that the higher the number of the gauge, the thinner the metal. The thicker the piece of sheet metal, the heavier in weight the material is for building.

Our team has to pay close attention to these factors when serving clients because sheet metal objects can be dangerous if weight and thickness are ignored. APX York Sheet Metal measures gauge down to the thousandth of an inch to ensure even balance and to create a tight fit for all the pieces of your project.

Why Sheet Metal Thickness Matters

The thickness of sheet metal affects the workflow of a job from beginning to end. With each custom sheet metal fabrication design, our team plans every move to match the blueprint. This means that how we go about completing projects depends on the thickness of the material we are working with.

Steps in the custom fabrication process such as bending and cutting require us to choose the proper thickness and tools for each job. Sheet metal that is smaller in gauge calls for more pressure to bend and stronger equipment to cut with ease. Fortunately, our team has the skills, tools and knowledge to laser-cut, bend, weld, grind and powder-coat sheet metal for any size project.

Working With APX York Sheet Metal

Completing custom sheet metal fabrication is a complicated process, but APX York Sheet Metal understands how to make products both efficient and functional. We take the necessary steps to discover as much as we can about your product and fabrication needs. Whether your design will be exposed to intense weather conditions or holds immense weight, APX York Sheet Metal creates custom sheet metal fabrication parts for a number of industries throughout Pennsylvania.

With 71 years in business, our family-owned operation specializes in OEM manufacturing parts, industrial enclosures and cabinets, construction equipment and more. We offer a quick turnaround on custom sheet metal fabrication and shipping is handled in-house for accuracy.

For more information about APX York Sheet Metal and our services, contact us for a quote today to see how we can bring your next project to life.

Hole Positions in Sheet Metal Fabrication

Hole positioning is an essential aspect of custom sheet metal part design. Though engineers often rely on CAD or other design programs when placing holes in their designs, it's important to consider how the fabrication process will impact their performance. Placing a hole too close to a part's edge or bend radius can affect its durability, appearance and function.

When you send a part design to manufacture, you expect the final product to look and function how it does in your plans. As a result, you need to plan hole positioning correctly the first time. Understanding hole positioning in sheet metal fabrication can save you time and money and help your manufacturer deliver the results you're after.

What Happens When a Hole Is Positioned Improperly?

A hole placed too close to the edge of a sheet metal part has the potential to affect performance. Designed to attach the part to another component using a rivet or other fastener, the hole and surrounding metal may tear or crack, compromising the structural integrity of the product. This effect worsens as more force is applied. Depending on the application, this cracking can decrease the part's lifespan or even make it unusable.

When a hole is placed too close to a future bend in the metal, it can become warped during bending. This warping occurs when part of the hole is affected by the pull of the bending process. The bend drags the surrounding metal and changes its shape, resulting in a deformed hole that's difficult or impossible to accurately thread. The only ways to avoid warping are to drill the hole after bending, which can be expensive, or to move the hole position farther from the bend radius.

Calculating Minimum Edge Distance and Bend Distance

Selecting a hole position too close to a part's edge or bend radius can significantly impact the performance of the final product. Fortunately, calculating a better hole placement is usually simple.

For applications where hole placement must be near the edge, the hole distance from the edge should always be equal to or greater than material thickness. Keep in mind, however, that some applications require more distance. For example, you may want to increase the distance to 1.5 times the material thickness or more for complex designs in the material handling or construction industries.

To calculate how close a hole can be to a bend, you need to use a different formula. In most cases, minimum hole bend distance equals 1.5 times sheet thickness plus bend radius, though the multiplying factor may increase as hole size increases in diameter.

Though these calculations can help you approximate the minimum distance you'll need to place between a hole and the edge or bend in sheet metal, different situations call for different specifications. Other factors to consider include:

  • Material ductility

  • Intended application

  • Hole diameter

Contact the Fabrication Experts at APX York Sheet Metal

Proper hole positioning helps ensure a smooth fabrication process and a final product that performs as expected. At APX York Sheet Metal, we have 71 years of experience in custom metal fabrication. If you need a manufacturer capable of managing precise hole positions in sheet metal, we can help. Contact us for a free quote today to see how we can manufacture your design.