INTRO TO SUBTRACTIVE MANUFACTURING

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Subtractive manufacturing can be performed manually by a machinist. More commonly it’s a highly complex process used by a CNC machine.

It is a decades-old practice with a demonstrated history of effectiveness in the prototyping process and manufacturing products. The goal for your project will determine if it is the correct process for your needs. 

 Subtractive manufacturing is like the process an artist uses to create a sculpture. The machinist or CNC programmer, like the artist, uses specialized tools to carve metal materials into the desired shape.   

The different techniques used by the craftsman or artist create the specific details requested by the client.

If you want to understand subtractive manufacturing further and whether it aligns with your needs, consider Glenn Metalcraft Inc. They are an industry leader with a customer service focus.

What is subtractive manufacturing?

CNC machine cutting example of subtractive manufacturing

Subtractive manufacturing is aptly named since it involves removing or subtracting materials to produce the end product. One method of implementing subtractive manufacturing utilizes a computer numerically controlled or CNC machine

The process begins with a rough slab or bar of material. Then, a machinist removes the excess until it reaches the final shape of the prototype or product being manufactured. You can imagine it like a sculpture. Your piece begins as a rough block but takes on a more complex shape through detailed carving. 

Subtractive manufacturing can be further broken down by the machines and manufacturing technologies used. 

Conventional machining uses three-axis cutting tools so that the block does not need to be manually flipped or turned. Conventional lathes, milling machines, and drill presses produce basic geometric designs.

Unconventional machining is ideal for working with brittle materials or producing more intricate and complex shapes. It uses a variety of processes to remove excess materials. This method can use a combination of mechanical, electric, thermal, or chemical methods to fashion the block into the desired shape.

What is the difference between additive and subtractive manufacturing?

CNC machine drilling example of subtractive manufacturing

The difference between additive and subtractive manufacturing is stated within their names. One method adds material; the other method subtracts material. 

Additive manufacturing involves adding material to create the desired part. Adding layers to the workpiece forms the designated object. 

Like a CNC machine, a 3D printer is programmed to create a 3d printed piece. The printer then builds up the shape from raw materials. Specific industries that utilize additive manufacturing include the medical and dental device industries. 

Subtractive manufacturing involves removing material from solid blocks to fashion the desired shape. Manufacturers can use it with many different metals, such as aluminum and brass. A machinist or CNC machine system will remove metal using drilling, milling, or turning. The process will clear away segment by segment until the result is your product or prototype. 

However, the two processes are not mutually exclusive. On the contrary, many manufacturers use both together to take advantage of each process’s unique advantages.

Advantages of subtractive manufacturing

CNC Machine Turning as an example of subtractive manufacturing

There are many advantages of subtractive manufacturing, so it has remained a popular production method after decades of use. 

Subtractive manufacturing usually results in much smoother surface finishes than the “stepped” surface, which results from using an additive manufacturing process. 

Why does the type of finish matter? If your product needs to slide, you will want the smooth finish that subtractive manufacturing provides. 

The texture matters if you use your prototype in your sales and marketing process. Your customers will be more likely to believe that your product is the right fit if it has the right feel. 

Computer numerically controlled systems are commonly utilized in the subtractive manufacturing process. First, the CNC software reads the design provided and instructs the CNC machine on creating the product. It then prescribes how to cut, drill, and channel your components. 

This level of automation means that larger-scale production can be handled with greater ease and less human involvement. 

The tools used in subtractive manufacturing are exact and can create intricate or tight geometric designs. These types of complex shapes may be otherwise difficult to mold or cast.

Subtractive manufacturing techniques

CNC Machine Abrading example of subtractive manufacturing

Many subtractive manufacturing techniques are used. However, the main approaches can be divided into three broad categories. Those are: 

  • Cutting, 
  • Machining, and
  • Abrading.

Cutting involves using saws, blades, or other such tools to remove excess material. 

Machining is when tools move around or across the raw material to shape it. CNC machining involves turning, milling, or drilling the item. 

Finally, abrading is when the raw material is sanded down or polished using an abrasive substance. 

The type of process used is dependent on the type of material used.  A manufacturer needs a deep knowledge of metals to apply those processes to create the right design effectively. 

Subtractive manufacturing examples

CNC machine being programmed by a manManufacturers can apply subtractive manufacturing in various industries, including medical, dental, automotive, aerospace, and agriculture.

From gears in an airplane engine to garden tools, subtractive manufacturing can produce many products. This manufacturing technique can even make jewelry! Glenn Metalcraft Inc. uses its decades of industry experience to create items that might otherwise seem impossible!

Subtractive manufacturing has earned its place as an effective fabrication process in most machine shops. Its long history has improved by adding automation and software to allow many additional applications. Moreover, its unique properties mean it can create tight geometric shapes with a smooth and polished finish. 

Hybrid Manufacturing, the Future of Subtractive Manufacturing

For a long time, subtractive manufacturing has been the go-to for detail and finish work because it’s simply the best method. But today, additive manufacturing gives us new shapes and structures possibilities.

The best of both worlds – additive and subtractive techniques combined on the same machine. This is what we call hybrid manufacturing. With this method, you can create a new part from scratch with 3D printing and then use CNC methods to finish it. 

With this technology, you can switch between methods as you please. For instance, start by 3D printing a layer of material, then use subtractive machining on it, and add another layer afterward. 

Why Glenn Metalcrafts Inc.?

Glenn Metalcrafts Inc. specializes in assisting the OEM industry in creating prototypes and manufacturing the products that build your success. Our company brings to the table decades of experience, advanced equipment, and the advice of metal industry experts. We manufacture products others would not even consider. 

Glenn Metalcrafts Inc. builds solid relationships and grows alongside its customers. It is selective in its clientele to achieve the right fit. Reach out today to find out how Glenn Metalcrafts Inc. can make your manufacturing idea a reality.

 

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