Probably one of the most impressive applications for 3D printing I have seen to date is the work being done by Phoenix-based Local Motors. Last year they surprised the world, and certainly the automobile industry, when they 3D printed the Strati car live during the International Manufacturing Technology Show in Chicago. Since then, the company has gone on to print additional Strati cars, each time improving production speed and making valuable enhancements to the methods they utilize.
Thus far all the cars have been printed using an ABS/carbon fiber composite which, according to internal strength tests by the company, can stand up to vigorous stresses. As we look to the future and as new materials come to market within the desktop 3D printing space, one must wonder if multiple materials may eventually be used during the print process. Could we one day 3D print an entire vehicle including the mechanical aspects of it, glass, carpet, etc? I’m willing to bet that this day may be here sooner than many people can imagine.
This week Local Motors indicated that they are at least beginning to think this way as well. While they are quite the distance away from printing mechanical parts or pieces of a car’s engine, they are now testing new materials for specialized manufacturing of parts for their vehicles. The first two such materials that we have become aware of are Fenner Drives’ NinjaFlex and SemiFlex.
“Recently we’ve been test printing NinjaFlex and SemiFlex (also a NinjaFlex product),” explained James Earle, a Local Motors staff member. “We’re at the stage where I’m beginning to dial in the print process to ensure a reliable print. There’s still a lot of testing to be done on each material, but they are promising for use in the print process. We’re hoping to use one or both for crash structures (i.e. bumpers) to minimize the impact on the vehicle. In that sort of application, the impact would mostly be low speed. We have also talked about using NinjaFlex for things like seats and dashboard covers to lend a more squishy feel to the interior.”
For those who are not aware, NinjaFlex is an almost rubber-like material which allows for stretching and provides an almost cushion-like feel if printed with a honeycomb infill structure. SemiFlex, on the other hand, is a bit more rigid, but still flexible. It is stronger than NinjaFlex and better at absorbing shock. These materials, unlike that of the much more rigid ABS composite that Local Motors is currently printing with, would be perfect for anything that needs to have a bit of a give to it.
“The other possible applications for these products relates to inner-laminar bonding,” noted Earle. “Because the bond strength of the NinjaFlex is so high, we want to look into using the material in conjunction with the CF-ABS to create a structure that is both strong and rigid.”
“NinjaFlex is far more flexible than the 20% carbon-filled ABS thermoplastic polymer currently used in the 3D printed Strati,” explained Brian Wilkins of Local Motors. “It also doesn’t have adhesion issues like ABS. These facts make the material particularly intriguing, so we’ve begun performing more detailed tests.”
As Local Motors continues to improve their fabrication process and we head into the end of this year, closer to the company’s launch of their 3D printed vehicles, it will be interesting to see what other materials they decide to use. Let’s hear your thoughts on all of this in the Local Motors forum thread on 3DPB.com. Check out the video below showing multiple tests that the team at Local Motors put a brick 3D printed with Ninjaflex through: