Section: New Results

Ribbed support vaults for 3D printing of hollowed objects

Participants : Thibault Tricard, Frédéric Claux, Sylvain Lefebvre.

In additive manufacturing, and in particular with the popular filament-based fabrication, the printing time remains a major constraint. In a typical print, most of the time is spent filling the interior of the object. Based on this observation we explored how to print an object as empty as possible. The difficulty is that any deposited material has to be supported from below to prevent the object from collapsing.

We developed a simple, yet very efficient, algorithm that generates a lightweight ribbed support vault infill (see Figure 4). Our algorithm sweeps once through the slices from top to bottom, detects non-supported points, and connects them with a segment to the closest already supported points. The endpoints of open segments are eroded from one slice to the next. This process generates hierarchical ribbed support vaults that quickly retract and merge with the enclosing walls, while offering printability guarantees.

Our approach greatly reduces material usage (reaching parts as empty as 98%) and thus strongly reduces print time. Nevertheless it guarantees printability, and scales to very large inputs.

This work originated from the University of Limoges and was the master topic of Thibault Tricard, under the supervision of Frédéric Claux and in collaboration with Sylvain Lefebvre. The work was published in Computer Graphics Forum in June 2019 [16].

Figure 4. A 3D bunny model printed with our internal ribbed supports. It is mostly empty, with the ribbed vaults providing just enough support to prevent filament to fall during manufacturing.