Fast, Large, and Accurate 3D Printing

To achieve the goal of fast and large 3D printing at high resolutions, certain other criteria must be met. First, the method of printing should have good baselines for printing speed, build volume, and resolution. This excludes FDM printing, (slow, poor z-axis resolution) SLA printing (slow, small build volume) and SLS/SLM methods (slow). Niche methods can be similarly counted out. What remains is DLP printing - specifically top-down DLP printing using multiple projectors, because that enables continuous printing over a wide area.

Second, the limitations of DLP need to be mitigated. These limitations primarily stem from problems associated with resin flow and overzealous curing. Printing thick features requires resin to move further over the already-printed surface; when it fails to do so this results in resin starvation, which is a print failure. Printing thin is a solution.

However, printing thin has its own issues: DLP printing sets the form of the object, but the partially cured resin remains soft and flexible, meaning it can warp during the print (due to thermal contraction), especially if the print is large – again causing print failure. To solve this problem, this research is focusing on co-opting a strength of DLP printing – printing lattice structures. By attaching a conforming lattice to one side of a thin surface, the argument is that this will reinforce it enough to give it the strength it would have if printed slower and thicker, prevent print failures, and maintain maximum print speeds. As such, this solution is related to design for additive manufacturing best practice.

Rhino and Grasshopper have been utilised to develop an algorithm which can apply reinforcement to a surface, with the traits of that reinforcement being manipulable by the user. Test prints using basic surfaces have been used to determine the printability of a series of different reinforcement structures.The optimal reinforcement techniques have then been applied to case study objects to demonstrate the ones that can be printed fast, large, and accurately – and potentially improved by structural reinforcement.