I was reading recently about a new 3D printer that is, not unlike all the other 3D printers unveiled these days, intended to disrupt injection molding. This particular offering however, (from a major corporation that will remain unnamed) did claim some specifications that would intrigue those with even the tiniest curiosity about the technology. But before all of the toolmakers and process engineers out there start packing it in and looking for new careers, let’s delve in a bit further.
Cost per part is important when considering any manufacturing options, traditional or otherwise. While the price tag of this new machine is easily found in many of the news release based articles circling the web right now, there is very little information regarding cost per part. Statements using marketing terminology that make claims such as, “lowest cost per part,” contain zero information to validate the assertion. This is more than likely due to the relative newness of this particular platform and minimal objective reviews as of yet. While I cannot myself make contentions as to any actual costs for material or what final price per part projections could be, I can say that this particular manufacturer, that will remain unnamed, is well known for generating considerable profits through repeat material sales and not necessarily hardware. This, “Voldemort” of companies (a reference to their anonymity and not a proclamation of evil) also makes great effort to assure that any material used in their machines is controlled to guarantee annuity revenue over the lifespan of the platform. While there is some discussion of alternative materials offerings and even partnerships on this front, you can rest assured that this strategy will continue in some form as it is far too lucrative to be left completely susceptible to direct competition.
The reason there seem to be endless suppliers of plastics parts to such a varied swath of industries is a simple exercise in controlling margins. It is typically cheaper for a contract manufacturer, who already owns and maintains specialized machinery, has the qualified workforce, and provides parts at a cost per unit, to produce these parts than it is for a single all-in-one manufacturer to manage everything themselves. If the automotive industry, with their already lofty overhead in skilled labor and advanced technology, also had to absorb the costs of maintaining entire segments of the plastics, steel, and electrical industries, our primary transportation method would probably contain pedals or other people. While 3D printing is an amazing way of adding customization or reducing cost on “one-off” parts, it is currently relegated to a few functional prototypes or highly specialized, low volume manufacturing.
Processing speed is also an important factor when considering costs. This new machine boasts a build speed of 200 – 300in3/hr., depending on exact machine model and settings. A bit of quick math can tell us that this machine can produce a plastic product with roughly the same volume characteristics as, that coffee cup right there on your desk, in a mere… 3 – 5 minutes? That can’t be right. Yep, checked it again, a standard coffee cup should consist of roughly 12in3 - 14in3 of material based on measurements which works out to 3 – 5 minutes of build time at the manufacturer stated 3.33in3 to 5in3 per minute capacity. (My math is bad but not that bad, and the internet.) This is no doubt a great increase in speed, but it is quite a disparity from what is necessary to really challenge injection molding.
Another obstacle to additive manufacturing revolves around how the parts are constructed. When a plastic part is injection molded, melted material flows into a mold and hardens creating exceptionally strong parts and, depending on the mold, tolerances of plus or minus thousandths of an inch. One of the issues with additive manufacturing has always been the dimensional accuracy of the process. 3D printing, not FDM, SLA, or SLS, utilizes printing similar to that of a desktop inkjet printer, but adds a third axis. The problem is in achieving small enough droplet and layer sizes necessary for a dimensionally accurate part that is not weakened by a non-uniform surface. Many lesser offerings are only capable of producing parts that require extensive post processing work to achieve the tolerances of the intended design. These parts are also quite limited in terms of strength due to the literal gaps between the individual droplets and layers. This new offering seems to have improved on that issue. With a resolution of 1200dpi this machine is capable of producing a droplet of material measuring just 0.000833”. The accuracy is expanded further with a layer thickness as diminutive as 0.0025”. With these dimensional improvements this new technology may have taken a big step toward producing viable finished parts from a 3D printer.
The real truth surrounding this new machine really come out the farther you scroll down the page. As the headlines of some of these stories read like dialog from a plastic-centric Bond Villain’s vernacular, “the ultimate goal is to disrupt injection molding,” they shift to objectives that are more viable for this platform as the text continues. Focus is shifted to the boundless customization opportunities, open software platform, and business partnerships that are telling of the machines intended use. These user-friendly customization efforts quickly become the talking points throughout nearly all of the stories that I read. This does not take away from the technological advancements this machine offers to the market in any way, but it does put things into perspective with regards to production capacity. However, with the constant aspiration to not just obtain things, but to have those things unique to one’s self made me realize that this machine may not need to be as efficient as injection molding to still find considerable success.
While it is likely true that once we have peaked through the door at production free from expenditures such as tooling, that the toolmaker’s demise is a forgone conclusion, my guess is that this technology won’t evolve to truly compete with traditional methods for some time. In the interim, injection molding can produce a great deal of products at low costs. These products can then be sold in stores where a customer can make them their very own by adding a 3D printed unicorn… or whatever you want. Don’t judge.