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3D Printing Is a Great Tool but Use It Wisely

Wednesday, March 08, 2017

The advances in 3D printing technologies continue to accelerate, with more printers entering the market with new capabilities, materials, and price points. For specific applications, they are enabling lower cost, faster solutions, and indeed can sometimes produce parts that are impossible or very expensive to produce using traditional methods.

 

3D printing can provide faster turnaround on prototype parts, enabling engineers to often more rapidly develop and test prototypes without having the need for molds or other processes. Those parts typically can be made at lower cost as well.

 

But these tools should not become a substitute for good DFM-oriented engineering practices involving simulation and analysis during the design phases. A product development methodology that utilizes simulation and analysis early and often during the design process, while taking advantage of the advances in 3D printing, is a proven way to achieve fast time to market with a manufacturable product. There are a number of key reasons for this:

 

  • 3D printed parts do not necessarily represent what the manufactured part will be with respect to materials, fit, finish, or performance/strength perspective.
  • Injection molding-based parts require draft angles to be included—3D printed parts do not.
  • Your accuracy may not be as accurate as you need—3D printing is primarily a prototyping technology, at least for today. As with any viable test part, the dimensions have to be precise within specified limits in order for the part to work. While 3D printers have made advances in accuracy in recent years, many of the materials and processes are not as accurate as a traditionally formed part; and there are feature size limitations, particularly for smaller parts.
  • Running worst case testing scenarios may not be feasible with 3D printed parts as they may not survive, nor does their performance provide an accurate representation of how production parts will perform.
  • Tolerances are different for 3D printed parts vs. production parts—tolerance analysis should still be run as part of the DFM methodology
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    Other considerations for utilizing 3D printers include:
    • 3D printed parts are built in additive fashion—that is, layer-by-layer from the ground up. While the technology is a major process breakthrough, the materials that can be used are still limited. For instance, while there are more and more metals-based 3D printers coming to market, the majority of 3D printing materials are plastic, as it can be deposited down in melted layers to form the final part. The kinds of plastic vary among the likes of high strength and high temperature materials, so part strength can't accurately be tested in many cases. There are several more specialized materials that companies are printing in, such as glass and gold.
    • Parts created additively through 3D printing are also limited in size (for desktop printer applications).
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        Acorn has a 3D printer in-house (it’s used extensively) and has access to suppliers that are continually adding to their 3D printing capabilities. We embrace the utilization of this technology as part of our overall design methodology, but it is no substitute for a rigorous engineering process that includes simulation and analysis.




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