Analisa Kinematika Monobike Mechanical Toys Menggunakan GNU Octave dan Solidworks

Industry era 4.0 allows the use of cyber technology, both physical and non-physical, in all aspects of life, including the toy industry. 3-dimensional printers as a key technology industry 4.0 plays an important role. Before it is printed using a 3D printer, it becomes a real product ready to be marketed, first the product is simulated to find out if the toy product can move according to the kinematics that we design. This analysis includes the displacement, velocity, and linear and angular acceleration of the Monobike component. In this research, the analysis of component movements is limited to Link 3. In this study, a toy that can mimic the motion of an object as precisely as possible is determined, which is a monobike toy. Monobike mechanical toys mimic human activities of pedaling a bicycle. The methodology in this research is as follows: 1) Determine the dimensions of the monobike component, 2) Determine the monobike drive components, 3) Make a monobike kinematic diagram, 4) Perform kinematic analysis using the position vector of the monobike component, 5) Perform displacement, velocity calculations , and theoretical acceleration with Excel, 6) Perform kinematic analysis with Solidworks, 7) Comparison of theoretical calculation results and Solidworks simulation results. Based on the results of theoretical research and Solidworks simulations, the values ​​of displacement, velocity and acceleration are close. The average error for linear displacement is 0.261%, linear velocity 0.852%, linear acceleration 0.7664%, angular velocity 0.372%, and angular acceleration 0.492%. Kinematic analysis in monobike mechanical toys theoretically using Excel and simulation with Solidworks software, the results are more or less the same, so it can be said that this research is accurate. Solidworks is recommended as software that can be used to simulate movements in kinematic analysis

Minimizing material consumption of 3d printing with stress-guided optimization

3D printing has been widely used in daily life, industry, architecture, aerospace, crafts, art, etc. Minimizing 3D printing material consumption can greatly reduce the costs. Therefore, how to design 3D printed objects with less materials while maintain structural soundness is an important problem. The current treatment is to use thin shells. However, thin shells have low strength. In this paper, we use stiffeners to stiffen 3D thin-shell objects for increasing the strength of the objects and propose a stress guided optimization framework to achieve minimum material consumption. First, we carry out finite element calculations to determine stress distribution in 3D objects and use the stress distribution to guide random generation of some points called seeds. Then we map the 3D objects and seeds to a 2D space and create a Voronoi Diagram from the seeds. The stiffeners are taken to be the edges of the Voronoi Diagram whose intersections with the edges of each of the triangles used to represent the polygon models of the 3D objects are used to define stiffeners. The obtained intersections are mapped back to 3D polygon models and the cross-section size of stiffeners is minimized under the constraint of the required strength. Monte-Carlo simulation is finally introduced to repeat the process from random seed generation to cross-section size optimization of stiffeners. Many experiments are presented to demonstrate the proposed framework and its advantages

PENGEMBANGAN DESAIN DAN MANUFAKTUR MAINAN MEKANIKAL EDUAKTIF UNTUK MENDUKUNG KEMAJUAN INDUSTRU KREATIF

Abstrak Mainan sebagai peraga edukasi Mekanika Fisika telah banyak dilakukan di sekolah-sekolah maupun perguruan tinggi (PT) di dunia, sementara sebagai peraga untuk menjelaskan berbagai macam gerak dan mekanisme yang menimbulkannya belum banyak dilakukan (Kinematika). Mainan mekanikal edukatif adalah mainan yang bisa bergerak yang mampu menghasilkan gerakan mirip seperti aktifitas tertentu orang, hewan, atau mesin. Sumber penggerak mainan mekanikal yang hanya satu dan berbentuk rotasi, tidak seperti robot dimana semua sendi diberi motor listrik yang bisa dikendalikan, menunjukkan bahwa mekanisme kinematika yang digunakan bisa sederhana hingga sangat kompleks bergantung pada banyaknya bagian mainan yang harus digerakkan. Paper ini membahas pengembangan desain dan manufaktur mainan mekanikal edukatif sebagai peraga edukasi yang terbukti sulit dilakukan secara manual, seperti selama ini dilakukan di TDC (Toys Design Center). Dengan menggunakan perancangan berbasis software CAD (Computer Aided Design) reproduksi dan modifikasi produk mudah dilakukan. Gerak produk juga bisa disimulasikan tanpa harus membuat dan merakit seluruh komponennya terlebih dahulu, seperti pada proses perancangan manual. Kata Kunci : mainan mekanikal, mekanisme kinematika, peraga edukatif, Toys Design Center, CA

Computational Design and Optimization of Non-Circular Gears

We study a general form of gears known as non‐circular gears that can transfer periodic motion with variable speed through their irregular shapes and eccentric rotation centers. To design functional non‐circular gears is nontrivial, since the gear pair must have compatible shape to keep in contact during motion, so the driver gear can push the follower to rotate via a bounded torque that the motor can exert. To address the challenge, we model the geometry, kinematics, and dynamics of non‐circular gears, formulate the design problem as a shape optimization, and identify necessary independent variables in the optimization search. Taking a pair of 2D shapes as inputs, our method optimizes them into gears by locating the rotation center on each shape, minimally modifying each shape to form the gear's boundary, and constructing appropriate teeth for gear meshing. Our optimized gears not only resemble the inputs but can also drive the motion with relatively small torque. We demonstrate our method's usability by generating a rich variety of non‐circular gears from various inputs and 3D printing several of the

ACM Transactions on Graphics

We present an interactive design system to create functional mechanical objects. Our computational approach allows novice users to retarget an existing mechanical template to a user-specified input shape. Our proposed representation for a mechanical template encodes a parameterized mechanism, mechanical constraints that ensure a physically valid configuration, spatial relationships of mechanical parts to the user-provided shape, and functional constraints that specify an intended functionality. We provide an intuitive interface and optimization-in-the-loop approach for finding a valid configuration of the mechanism and the shape to ensure that higher-level functional goals are met. Our algorithm interactively optimizes the mechanism while the user manipulates the placement of mechanical components and the shape. Our system allows users to efficiently explore various design choices and to synthesize customized mechanical objects that can be fabricated with rapid prototyping technologies. We demonstrate the efficacy of our approach by retargeting various mechanical templates to different shapes and fabricating the resulting functional mechanical objects