9th Congress of Innovation, Science and Technology of the IFSP
A STUDY ABOUT FREE CAD PLATFORMS ANA LUIZA POLETTO LOSS¹, FABRICIU ALARCÃO VEIGA BENINI² 1 Graduated in Aircraft Maintenance Technology, PIBIC Scholarship , IFSP, Câmpus São Carlos,
[email protected] 2 Teacher of basic education, technical and technological, area industry, IFSP, Câmpus São Carlos,
[email protected]
Presented at 9th IFSP Innovation, Science and Technology Congress December 11-13, 2018 - Boituva, Brazil A STUDY ABOUT FREE CAD PLATFORMS ABSTRACT: The present work deals with the use of free CAD software (Computer Aided Desing). Due to high cost for maintain this design programs, the piracy became recently a frequent alternative not only by students, but also small companies. Aiming to minimize this problem, different platforms of free CAD softwares are being analyzed. At the end of the study, the results will be compared through already established parameters. KEYWORDS: Free softwares, piracy, CAD, drawing, modelling. INTRODUCTION From more rustic to more modern features, CAD software can be used to model virtually any object or structure (LOSS; BENINI; MARONA, 2018). However, to maintain the high quality and support of these products, they require a high investment. Be it in licenses, often expensive, or in good computers with processing power. Unfortunately, all this ends up being an invitation to use cracked programs, leaving the institution that adopts such a practice vulnerable to lawsuits, in addition to harming the developers of such platforms. Seeking a way to minimize the use of illegal concessions, 25 softwares were selected for analysis. Being the first payment, to be used as a reference to measure the others, besides being one of the best known in this area in the market. For study must meet some rules, be free, compatible with the maximum of possible operating systems and preferably open source. For testing, a reducer will be used whose application can be used in mobile robotic units capable of moving in known environments (BENINI, 2016). The final analysis will consist of the extracted data, according to the parameters indicated in Table 1, which will be compared with our reference, Solidworks. MATERIAL AND METHODS The first studies consisted of the choice of 25 platforms. Among them are SolidWorks (used as reference for others), Google Sketchup, TinkerCad, Microsoft 3D Builder, FreeCAD, BRL-CAD, Blender, Meshmixer, Onshape, SolveSpace, nanoCAD, naroCAD, Salome, CoffeSCad, Open CASCADE, Medusa4, gCAD3D, T-FLEX CAD, SelfCAD, ar-cad freeCAD, PUPPICAD, MakerSCAD, 3DSlash, Sculptris, OpenSCAD In the next step, based on a project of Braga (2018), came the reproduction of some of the UAV, a reducer. It is a set of gears of various dimensions, in addition, there are the joints through the axles, bearings, moving parts and the carcass where everything is fixed (SILVEIRA, 2016). A bibliographic review was made through Gordo e Ferreira (2000) of how to draw such structures of these pieces, because they have a very specific size, having the pinion with 6 teeth and the crown with 60. Solidworks, as shown in Figure 1, was used to be followed as a model for the other systems. From it some criteria were created like, to be free for anyone poder baixar, sem a necessidade de licenças e de preferência open source para quem tiver interesse contribuir para melhorar o sistema.
Figure 1 - Gear model designed in Solidworks
Table 1 - Solidworks attributes used as comparison reference for other software
The second stage consisted of studies through literature and video lessons of each chosen free software, where later, the reference piece is reproduced. Based on the data extracted, a score is made according to each item in Table 1. These values correspond to the scores obtained in comparison with the platform that was used as reference, Solidworks, in which a score was assigned 4. If one of the attributes obtains an equal result to 4, it means that the functionality is close to the default template, if it is larger, it exceeds the equivalent feature in Solidworks, but if it is smaller, it will be less than 4, subdivided into 3 hierarchical levels. At the end of the tests will be compared and inferred which had better performance within the rules created. RESULTS AND DISCUSSION Firstly, preliminary studies were done of the platforms used and how to make the piece, according to the Telecurso (2000). Subsequently, this preparation served as the basis for all other programs. It was necessary to redo the initial design, because after the first impression it was verified by means of test that the pieces did not "meshing" or fit in a normal way. From this it was necessary to carry out a new study and new modeling of parts, based on the formulas of the Melconian (1991). Below is the formulas used to make the gears and where they are in the part the variables of the equations of the part, according to Figure 2. Do = M * Z
De : Do + 2 * M
Di = Do – 2 * Hf
H f = 1, 2 * M
M = Do/Z
H z = 2, 2 * M
To = M * π
Lo = T o/2
L = 9 * M
Pressure angle: alpha equal to 20 °
C c = (Do1 + Do2)/2
being, external diameter: De, Primitive diameter : Do, internal diameter : Di, circular pitch : To, module : M, number of teeth : Z, total tooth height : Hz, tooth toe height : Hf, height of the tooth head or M: Hk, addendum : Lo, tooth width : L, distance between centers : Cc, pressure angle: alpha Figure 2 - Memorial of calculation
Figure 3 - Drawing in SketchUp
Figure 4 - Drawing on Tinkercad
As a result of the second development, the pieces were created as an example of the pinions in Figures 3 and 4. Some of the CADs have almost no information and tutorials on how to get started, which affected the application and progress of the initial plan. Software that uses Python will be studied in the second semester, in time for presentation at this conference. CONCLUSIONS This research works with the intention of learning more about a certain platform, where it reproduces the same object for later comparisons. The same drawing was used in all programs and with this it was possible to observe the nuances of each one, such as. They have obtained several shapes, some square and others more rounded, however, this is due to the available resources of each program, but these differences do not interfere in the final result of causing them to "mesh". According to preliminary results of the platforms studied, so far only Google SketchUp and TinkerCAD, obtained notes close to the base model (notes 3 and 4) according to criteria 2 to 10 of Table 1. The other software received values below the reference. THANKS I would like to thank the IFSP for the space, materials and all the necessary support for this work, PIBIC, Professor Thiago Rodrigo Cicogna for making his 3D printer available for the project and for my supervisor Fabriciu Benini. REFERENCES BENINI, F. A. V. Um sistema Fuzzy para desvio de obstáculos em ambiente virtual conhecido. In: 1° Congresso de Pós-Graduação do IFSP, 2016, Matão, SP, Anais… vol. 1, pp. 1-4. BRAGA, I. N. C. Projetos com Caixa de Redução (MEC162). Disponível em: < http://newtoncbraga.com.br/index.php/110-mecatronica/robotica/9505-projetos-com-caixas-de-reduca o-mec162 >. Acesso em: 12/08/2018. TELECURSO 2000. Telecurso 2000 profissionalizante: elementos de máquinas 1. São Paulo: Globo,2000. cap 32. GORDO, Nívia; FERREIRA, Joel. Elementos de máquinas – TELECURSO 2000. SENAI - SÃO PAULO – 2009. Cap. 32, 33 e 34. LOSS, A. L. P.; BENINI, F. A. V.; MARONA, G. F.. Projeto estrutural de uma plataforma portátil para aquisição de imagem de leituras biométricas.In: WORKSHOP DE INOVAÇÃO, PESQUISA, ENSINO E EXTENSÃO, 3., 2018, São Carlos, SP. Anais... São Carlos, SP: IFSP, 2018. p. 171-174.ISSN 2525-9377. MELCONIAN, Sarkis. Elementos de máquinas. 10. ed. rev. São Paulo: Érica, 2012. 376 p. ISBN 9788571947030. SILVEIRA, A. R. G. Determinação analítica da correção de hélice em um par engrenado devido ao efeito da flexo-torção . Dissertação (Mestrado em Ciências). Escola Politécnica da Universidade de São Paulo, SP, 2016.TY - BOOK
