Friends or Foes: Additive and Traditional Manufacturing

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Like any modern technology, additive manufacturing (AM) made a big splash with the general public when it first came to fruition but was quickly met with skepticism by many engineers. AM is often misrepresented as a startup and upstart technology, setting out to dominate traditional manufacturing, which makes up 8.5 percent of the American workforce (12.85 million jobs). In reality, AM and traditional manufacturing are partners, not competitors, with AM representing another tool in the ever-expanding toolbox of the 21^st century.  

What is the difference between additive manufacturing and traditional manufacturing?  

Traditional manufacturing refers to using fabricating and machining to create products in high volume. Some common practices in traditional manufacturing are injection molding, CNC machining and sand casting. Many production lines leverage a mold to make high volumes of a singular product, an efficient and cost-effective practice that enables mass production.  

Additive manufacturing refers to the practice of industrial 3D printing, where instead of cutting, molding or casting a product, companies build it, layer by layer, inside a 3D printer that follows the path laid out by an STL file based on a CAD (Computer Aided Design) model. This approach has been adopted heavily by aerospace manufacturers, as well as the medical and dental industries because of the customization and unique geometries enabled by the technology.  

Benefits and Drawbacks of AM and Traditional Manufacturing 

Traditional manufacturing benefits:  

1. High-volume production. Traditional manufacturing allows businesses to produce a singular product quickly, with production lines that can run for 24 hours a day, meeting market demands efficiently.  
2. Cost-effective production. With high-volume production comes the capability to reduce cost-per-unit: the more you produce with traditional manufacturing, the less expensive each product will be to manufacture, in part because you can amortize the upfront tooling costs. 
3. Part consistency. Traditional manufacturing allows for strong part consistency, repeating the same automated manufacturing production with little deviation from the original design.  

Traditional manufacturing drawbacks:  

1. High material waste. Producing a singular unit with traditional manufacturing methods can create excessive waste. Subtracting material to reach the final product is the way it has always been done in machining, and much of that waste, in the form of chips, is unavoidable.  
2. Inability to deviate from original prototype design. Many traditional manufacturing processes rely on producing a tool used to stamp or mold the product. After the tool is made for production, there is little to no ability for production lines to modify its design.  
3. High cost for low to medium production levels. The amortization of the initial tooling expenses across production is key to decreasing cost-per-part. Without a large production order, the cost to manufacture each individual item is higher, eating into the bottom line.  

Additive manufacturing benefits:  

1. Material flexibility. Leveraging polymer or metal additive manufacturing opens opportunities for printing with multiple materials and selecting the optimal material based on the properties and characteristics that fit the intended application, rather than availability or material scarcity. This allows companies in aerospace, for example, to toggle between printing in titanium (Ti64) and aluminum (AlSi10Mg) based on the application.  
2. Digital warehousing and small-batch production. Additive manufacturers have coined the phrase ‘digital warehousing’ to describe having a library of STL files at your fingertips rather than products in a physical building. The ability to decide how many parts or products you want to print allows for limited production lines to be set up and run quickly, rather than having to re-invent the wheel (or stamp) each time.  
3. Customization and part consolidation. Additive manufacturing gives engineers the option to alter their designs and send them to the printer within minutes. There is no need to create a one-off tool for each product: the printer and STL file work in tandem to build a complete product. Designing with AM also allows for part consolidation via new, unique part geometries that would be impossible to produce subtractively.  

Additive manufacturing drawbacks:  

1. Upfront cost. The cost of purchasing an AM system can cause sticker shock at first for those new to industrial 3D printing. Purchasing an AM system is a substantial investment for most organizations, but similarly to the way traditional manufacturing amortizes the initial cost of a CNC machine, an AM system will pay for itself over time with its ability to print and change materials on demand based on your business specifications.  
2. Post-processing. The process of finishing parts made with AM directly after their build can require additional tools and equipment to complete the part production effectively. Although this can add time to your overall project completion date, it allows those with applications that will be on display to reach the optimal physical appearance for their applications.  
3. Build size restrictions. AM system build volumes vary by size and do not accommodate all application dimensions. Depending on the intricacies of the application, you may need an organization such as AMCM (Additive Manufacturing Customized Machines) to modify and build an custom 3D printer with added specifications such as a larger build volume, stronger lasers and fine detail resolution (FDR). 

How to know which process is right for you 

Both AM and traditional manufacturing have benefits and drawbacks—it all comes down to what the best fit is for your application and production goals. If you are making the exact same simple product in mass units, traditional manufacturing processes, such as injection molding, may be the more streamlined approach to production. If you are offering customization with a product, have intricate geometric designs or internal structures, or a production goal that may expand or contract over time, AM is worth considering for both short and long-term manufacturing.  

If you are interested in learning more about how AM can add to your production capabilities and portfolio, contact our EOS Additive Minds team to discuss your options and application goals today.