Dynamically controlled surface for 3D printers could help reduce waste

Traditional 3D printing uses the 'Fused Deposition Modelling' (FDM) technique, which prints layer-by-layer directly onto a static metal surface. The new prototype instead uses a programmable, dynamically-controlled surface made of moveable metal pins to replace the printed supports. The pins rise as the printer progressively builds the product.

The prototype was created by a team at the University of Southern California (USC) Viterbi’s Department of Industrial and Systems Engineering. Yong Chen, professor of industrial and systems engineering at USC and lead of the study, said that testing of the new prototype has shown it saves around 35 per cent in materials used to print objects.

“I work with biomedical doctors who 3D print using biomaterials to build tissue or organs,” Chen explained. “A lot of the material they use are very expensive – we’re talking small bottles that cost between $500 (£362) to $1,000 (£723) each.”

Chen added: “For standard FDM printers, the materials cost is something like $50 (£36) per kilogram, but for bio-printing, it’s more like $50 per gram. So if we can save 30 per cent on material that would have gone into printing these supports, that is a huge cost saving for 3D printing for biomedical purposes.”

In addition to the environmental and cost effects of material wastage, traditional 3D printing processes using supports is also time-consuming, Chen said.

“When you’re 3D-printing complex shapes, half of the time you are building the parts that you need, the other half of the time you’re building the supports,” he explained. “So with this system, we’re not building the supports. Therefore, in terms of printing time, we have savings of about 40 per cent.”

Chen said that similar prototypes developed in the past relied on individual motors to raise each of the mechanical supports, resulting in highly energy-intensive products that were also much more expensive to purchase and thus not cost-effective for 3D printers.

“If you had 100 moving pins and the cost of every motor is around $10 (£7), the whole thing is $1,000 (£723), in addition to 25 control boards to control 100 different motors. The whole thing would cost well over $10,000 (£7,233),” he explained.

The research team’s new prototype works by running each of its individual supports from a single motor that moves a platform. The platform raises groups of metal pins at the same time, making it a cost-effective solution, according to the team.

Based on the product design, the program’s software would tell the user where they need to add a series of metal tubes into the base of the platform. The position of these tubes would then determine which pins would raise to defined heights to best support the 3D-printed product, while also creating the least amount of wastage from printed supports. At the end of the process, users can easily remove the pins without damaging the product, the team added.

Chen added they could easily adapt the system for large-scale manufacturing, such as in the automotive, aerospace and yacht industries.

“People are already building FDM printers for large-size car and ship bodies, as well as for consumer products such as furniture. Their building times are really long – we’re talking about an entire day,” Chen said. “If you can save half of that, your manufacturing time could be reduced to half a day. Using our approach could bring a lot of benefits for this type of 3D printing.”