Computational design of steady 3D dissection puzzles

Dissection puzzles require assembling a common set of pieces into multiple distinct forms. Existing works focus on creating 2D dissection puzzles that form primitive or naturalistic shapes. Unlike 2D dissection puzzles that could be supported on a tabletop surface, 3D dissection puzzles are preferable to be steady by themselves for each assembly form. In this work, we aim at computationally designing steady 3D dissection puzzles. We address this challenging problem with three key contributions. First, we take two voxelized shapes as inputs and dissect them into a common set of puzzle pieces, during which we allow slightly modifying the input shapes, preferably on their internal volume, to preserve the external appearance. Second, we formulate a formal model of generalized interlocking for connecting pieces into a steady assembly using both their geometric arrangements and friction. Third, we modify the geometry of each dissected puzzle piece based on the formal model such that each assembly form is steady accordingly. We demonstrate the effectiveness of our approach on a wide variety of shapes, compare it with the state-of-the-art on 2D and 3D examples, and fabricate some of our designed puzzles to validate their steadiness

PELATIHAN DIVERSIFIKASI SUVENIR KHAS YOGYAKARTA

Abstrak: Permasalahan mendasar yang masih dihadapi oleh Industri Kecil Menengah (IKM) kulit di Yogyakarta adalah daya saing di pasar global serta tuntutan dan persyaratannya untuk dapat memenuhi selera konsumen. Salah satu cara untuk mengatasi permasalahan tersebut adalah dengan melakukan pendampingan teknik dalam bentuk pelatihan yang menghadirkan diversitas yang kaya inovasi dengan kualitas produk kulit yang lebih baik. Studi ini bertujuan untuk membina industri kulit di Yogyakarta untuk menghasilkan produk yang memiliki diversifikasi sehingga dapat menghadapi persaingan di pasar global. Pelatihan dalam bentuk workshop dilaksanakan selama tiga hari atas kerjasama Inkubator Bisnis Industri (IBI) dan Unit Penelitian dan Pengabdian Masyarakat Politeknik ATK Yogyakarta bersama Dinas Perindustrian Koperasi Usaha Kecil dan Menengah, Pemerintah Kota Yogyakarta dan Sekolah Tinggi Seni Rupa dan Desain VISI Indonesia. Melalui pelatihan, para peserta yang terdiri dari IKM perkulitan di Yogyakarta berjumlah 19 orang, mampu menghasilkan tas tangan dan tas selempang (sling bag) dengan berbagai kombinasi seperti anyaman bambu, sulaman kristik dan aksesoris perak. Berdasarkan hasil evaluasi dalam bentuk wawancara dan kuesioner, rata-rata nilai kepuasan peserta terkait kesesuaian dengan deskripsi pelatihan yang diharapkan dilihat dari cara penyampaian, kesesuaian materi, dan koordinasi panitia selama pelaksanaan adalah 90%.Abstract: The main problem faced by the Leather Small and Medium Enterprises (SMEs) in Yogyakarta is competitiveness in the global market as well as demands and requirements to be able to meet consumer needs. One way to overcome this problem is to provide technical assistance in the form of workshops that present a diversity of innovations with better quality leather products. This study aims to foster the leather industry in Yogyakarta to produce diversified products so that they can face competition in the global market. The training was carried out for three days in collaboration with the Industrial Business Incubator (IBI) and the Research and Community Service Unit of Politeknik ATK Yogyakarta with the Small and Medium Enterprise Cooperative Industry Office, Yogyakarta City Government. Through the workshop, the participants were able to produce leather clutches with various combinations such as bamboo woven, cross stitch embroidery and silver accessories. Based on the results of the evaluation, the average participant satisfaction score related to suitability with the expected training description seen from the delivery method, material suitability, and committee coordination during implementation was 90%

Interlocking structure design and assembly

Many objects in our life are not manufactured as whole rigid pieces. Instead, smaller components are made to be later assembled into larger structures. Chairs are assembled from wooden pieces, cabins are made of logs, and buildings are constructed from bricks. These components are commonly designed by many iterations of human thinking. In this report, we will look at a few problems related to interlocking components design and assembly. Given an atomic object, how can we design a package that holds the object firmly without a gap in-between? How many pieces should the package be partitioned into? How can we assemble/extract each piece? We will attack this problem by first looking at the lower bound on the number of pieces, then at the upper bound. Afterwards, we will propose a practical algorithm for designing these packages. We also explore a special kind of interlocking structure which has only one or a small number of movable pieces. For example, a burr puzzle. We will design a few blocks with joints whose combination can be assembled into almost any voxelized 3D model. Our blocks require very simple motions to be assembled, enabling robotic assembly. As proof of concept, we also develop a robot system to assemble the blocks. In some extreme conditions where construction components are small, controlling each component individually is impossible. We will discuss an option using global controls. These global controls can be from gravity or magnetic fields. We show that in some special cases where the small units form a rectangular matrix, rearrangement can be done in a small space following a technique similar to bubble sort algorithm

Symmetry-based decomposition for optimised parallelisation in 3D printing processes

Current research in 3D printing focuses on improving printing performance through various techniques, including decomposition, but targets only single printers. With improved hardware costs increasing printer availability, more situations can arise involving a multitude of printers, which offers substantially more throughput in combination that may not be best utilised by current decomposition approaches. A novel approach to 3D printing is introduced that attempts to exploit this as a means of significantly increasing the speed of printing models. This was approached as a problem akin to the parallel delegation of computation tasks in a multi-core environment, where optimal performance involves computation load being distributed as evenly as possible. To achieve this, a decomposition framework was designed that combines recursive symmetric slicing with a hybrid tree-based analytical and greedy strategy to optimally minimise the maximum volume of subparts assigned to the set of printers. Experimental evaluation of the algorithm was performed to compare our approach to printing models normally (“in serial”) as a control. The algorithm was subjected to a range of models and a varying quantity of printers in parallel, with printer parameters held constant, and yielded mixed results. Larger, simpler, and more symmetric objects exhibited more significant and reliable improvements in fabrication duration at larger amounts of parallelisation than smaller, more complex, or more asymmetric objects

Thermoplastics 3D Printing Using Fused Deposition Modeling on Fabrics

The creation of objects with integrated flexibility is desired and this can be achieved by additive manufacturing on fabric. We propose to use a textile fabric as a flexible joint and create to create an entire object with smaller parts called segments. Such a novel technique will bring integrated flexibility and folded assemblies using extrusion based additive manufacturing machines. The proposed process allows segments to be created flat one at a time on a continuous fabric, which will be suitable for flat to folded assemblies and eliminate size limitations of the 3D printer. Techniques considering object segmentation were used to unfold 3D models of objects into 2D patterns based on paper folding. The unfolding of models was specifically designed to allow manufacturability of the segmentations with no impedance from the 3D printer’s frame, where minimal segments were also desired. Three different textile fabrics based on cotton plain weave, plane weave acrylic, and polyester 200 denier ripstop fabrics were considered in investigations of the interfacial strength created with additively manufactured polylactic acid. Both treated and untreated fabrics were prepared simultaneously so that parts can be printed on top of them at a predefined spatial location. The interfacial strength of additive manufactured parts printed on the fabric were also tested as a function of print process parameters, fiber morphology, fabric properties, as well as surface modification of fabrics. The highest interfacial strength between additive manufactured materials and fabric was desired and tested for. Both adhesion peel testing and stress pull testing is used to determine the strength of the interface between the fabric and deposited additive manufactured parts. Results found that the interfacial strength reached a maximum of 5.18 and 0.435 MPa. For a conceptual square shelter design a series of triangular panels were created on fabric to be assembled into the shelter. It was conceptually determined that the resulting interfacial strength could keep a 40-kilogram large triangular, panel of this shelter, held upside done from removing from the fabric, given its own weight. From this result, it was determined that the interfacial strength is strong enough for use with the creation of large heavy objects that require flexibly in them for hinges. Rough and thick fabrics were found to promote interfacial strength the greatest with higher bed temperatures, this was because of mechanical interlocking being promoted. Pre-treatments of the fabrics were found to help with interfacial strength as well and have potential with higher environmental temperatures, but not as much as mechanical interlocking. Adhesion forces desired between fabric and 3D printed parts can be tailored per specific large object as needed, per segmentation, using this information. The proposed manufacturing method helps fabricate multifaceted large single objects with localized optimum process parameters and objects with integrated flexibility. The additive manufacturing on fabric method of object fabrication addresses the anisotropic nature of additive manufactured parts by allowing parts of the object be created separately from each other. This allows each part to be tailored for specific mechanical properties to achieve desired mechanical properties for the entire object. Mechanical strength, optimization of weight, interfacial strength, specific features or properties, and the ability to fold for storage or transportation of these objects could be tailored per application

Meso-Scale Digital Materials: Modular, Reconfigurable, Lattice-Based Structures

We present a modular, reconfigurable system for building large structures. This system uses discrete lattice elements, called digital materials, to reversibly assemble ultralight structures that are 99.7% air and yet maintain sufficient specific stiffness for a variety of structural applications and loading scenarios. Design, manufacturing, and characterization of modular building blocks are described, including struts, nodes, joints, and build strategies. Simple case studies are shown using the same building blocks in three different scenarios: a bridge, a boat, and a shelter. Field implementation and demonstration is supplemented by experimental data and numerical simulation. A simplified approach for analyzing these structures is presented which shows good agreement with experimental results

A Modern Craftsman Revival

Introducing concepts of Craftsman kit construction to the interior, as well as modern technology to lessen the cost of handcrafted details, opens the possibility to new methods of modular design in which interior units are configured around structural skeletons and central base points that provide supply lines to residential units. One example is Dutch design firm Minale-Maeda’s Keystones, a 3D printed connector that holds together any necessary components, like furniture. These keystones can be printed at home and save time and the need to obtain anything but essential components (website). The design firm works to create an “ongoing awareness of the possibilities of both mass-production and skilled craftsmanship” (L’arco Baleno, 2014). Another interesting example is Dutch design brand Fraaiheid’s Minimal Waste Table, which is created from one piece of laminated plywood with a CNC milling machine which makes for extremely minimal waste (Williamson, 2013). These examples of automation require a craftsman’s hand and mind to create the concept but introduce a modern approach to reducing waste, time and cost

FURNISH : new methodologies to intervene in public space

Descripció del recurs: 23 maig 2023FURNISH is the acronym of Fast Urban Responses for New Inclusive Spaces and Habitat, a project centred on transforming streets by repurposing them. The project was born during the COVID-19 pandemic, when the emergency triggered the need to creatively reframe the general understanding, not only of our behaviour, but also of our environment. Public spaces should evolve and become more inclusive places for everyone, especially for the most vulnerable. Under these challenging circumstances, FURNISH, a project led by CARNET, emerged to rethink the public space, while taking action in an inclusive and necessary manner. This book summarises the project since its inception in 2020, the new methodologies applied to intervene the public space, and the fantastic experimental results. Enjoy the book!