3D-printing of non-assembly, articulated models

Abstract

Figure 1: Starting from a 3D mesh (left), our system allows to intuitively add 3D-printable joints (center) that, when 3D-printed, create a functional, posable model with joints that exhibit internal friction. The model leaves the printer ready to use; no manual assembly is required. AbstractAdditive manufacturing (3D printing) is commonly used to produce physical models for a wide variety of applications, from archaeology to design. While static models are directly supported, it is desirable to also be able to print models with functional articulations, such as a hand with joints and knuckles, without the need for manual assembly of joint components. Apart from having to address limitations inherent to the printing process, this poses a particular challenge for articulated models that should be posable: to allow the model to hold a pose, joints need to exhibit internal friction to withstand gravity, without their parts fusing during 3D printing. This has not been possible with previous printable joint designs. In this paper, we propose a method for converting 3D models into printable, functional, non-assembly models with internal friction. To this end, we have designed an intuitive workflow that takes an appropriately rigged 3D model, automatically fits novel 3D-printable and posable joints, and provides an interface for specifying rotational constraints. We show a number of results for different articulated models, demonstrating the effectiveness of our method.

Design for Additive Manufacturing: Trends, opportunities, considerations, and constraints

“…Finally, AM can directly produce assemblies with moving or movable parts such as crank and slider mechanisms [68], gears [56], joints [55][56] [68] (Fig. 35), and hinges [29].…”

Boxelization

“…One potential way around this problem is to modify the geometry of the joints [Bächer et al 2012;Calì et al 2012], but such techniques are designed for larger joints and are difficult to apply to our intricate results. Fortunately, digital manufacturing technologies are constantly improving, and so we expect our framework to be more and more practical in the future.…”

“…In all these works, the object is cut into disjoint parts and reassembled, while our work searches for a single foldable object. A somewhat similar problem in terms of printing a single model, but for the creation of articulated models, was presented recently [Bächer et al 2012;Calì et al 2012]. Their challenge is more to assure pieces will function in a single configuration, while ours is to find a shape that can take on two different configurations.…”

The Making of a 3D-Printed, Cable-Driven, Single-Model, Lightweight Humanoid Robotic Hand

“…Each of the Inmoov robot's finger, which is made from six separate parts, needs three pins and adhesive to link the parts together. In comparison, our robotic hand's finger has adopted a new 3D model design inspired by non-assembly, articulated models (Cali et al, 2012). The new design of the joints integrates pin linkages to the fingers with an interlocking method.…”

“…Our robotic hand aims to mimic the grasping behavior of the human hand while staying simple in making and control of the robotic. With the help of Fused Deposition Modeling, 3D printed rigid endoskeleton (Tavakoli et al, 2017) and functional articulations non-assembly joint (Cali et al, 2012) are easy to apply to the robotic hand. It is also possible to integrate every joint into a single articulated hand 3D model.…”