Quite often when objects are being 3D printed, they have to include supportive structures that are subsequently cut off and discarded. A new print bed, however, is designed to minimize or even eliminate the need for such structures, thus reducing both waste and printing time.
Commonly used FDM (fused deposition modelling) printers build objects from the bottom up, by extruding successive layers of melted plastic. If those items include horizontally hanging sections, however, a supporting column of plastic has to run from the underside of those bits down to the print bed. Otherwise, the unsupported molten plastic will droop and collapse.
A person has to manually remove those supporting structures, once the printing process is complete. This takes some time, as does the initial printing of the structures. Additionally, although the cut-off plastic can sometimes be recycled, it's often simply discarded.
That's where the experimental new print bed comes in.
Designed by a team at the University of Southern California, it utilizes a single motor to selectively raise a series of flat-topped steel pins. Those pins take the place of the plastic support structures, gradually rising up to support overhanging parts of the item as it's being printed.
Although somewhat similar beds have been developed previously, they've required a single motor for each pin, thus increasing their energy requirements, cost and complexity. Plans call for the new, more efficient print bed to work with customized software, which would indicate where the pins were required on each unique print job.
"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," says Prof. Yong Chen, who is leading the project along with PhD student Yang Xu. "So with this system, we’re not building the supports. Therefore, in terms of printing time, we have a savings of about 40 percent."
A paper on the research was recently published in the journal Additive Manufacturing. The prototype print bed is demonstrated in the video below.
Source: USC Viterbi School of Engineering
