Computer Aided Design
Objectives
The main objectives of the Computer-Aided Design Course are:
1. To have an in-depth knowledge of the rules of Technical Drawing and Machine Drawing;
2. To understand and interpret 2D drawings correctly;
3. To be able to carry out detailed drawings of components and assemblies in CAD 2D software (bill-of-materials included);
4. To use CAD 3D software, in order to represent complex 3D parts and assemblies through parametric solid/surface modelling. To understand the concepts associated with the modelling of solids and surfaces using CAD 3D software.
5. To be able to create, edit and modify 3D parametric models of parts and assemblies, as well as to know how to measure and model components of machines also taking into account their assembly;
6. To be able to carry out CAD 3D modelling and CAD 2D drawings of mechanical elements and machines elements taking into account standardisation;
7. To understand the concepts of surface finish, dimensional tolerance, as well as geometric tolerance and to know how they are linked to the manufacturing processes. To know how to calculate tolerances taking into account standard adjustments recommended and to represent them through adequate symbology (CAD 2D);
8. To know the main welding processes used in the mechanical industry and to represent welded joints through adequate symbolic representation (CAD 2D);
9. To introduce the concepts of structural analysis by using the Finite Element Method (Solidworks Simulation) and reverse engineering (ScanTo3D).
10. To be able to print 3D parts using the FFF technique.
General characterization
Code
10633
Credits
6.0
Responsible teacher
António José Freire Mourão, Rui Fernando dos Santos Pereira Martins
Hours
Weekly - 5
Total - 70
Teaching language
Português
Prerequisites
No requirements are necessary.
Bibliography
Cunha, Luís Veiga da, Desenho Técnico, Ed. Fundação Calouste Gulbenkian, 15ª Edição, ISBN: 972-31-1066-0, 2004, Lisboa
Silva, A., Ribeiro, C.T., Dias, J. e Luís Sousa, “Desenho Técnico Moderno”; 11ª Edição, Editora Lidel, ISBN: 978-972-757-337-0
Manfé, G., Pozza, R., Scarato, G., Desenho técnico mecânico : curso completo : vols. 1, 2, 3; trad. Carlos Antonio Lauand, São Paulo : Hemus-Livraria Editora
Simões Morais, J., Desenho Técnico Básico, ISBN: 978-972-965-252-3, Ed. Porto Editora, 2006
Américo Costa, Projeto 3D em SolidWorks, 1ª Edição, Editora FCA, ISBN: 978-972-722-820-1
Teaching method
The teaching method used in theoretical-practical classes consists of oral presentations accompanied by drawings, diagrams, and summaries made by the Professor on the board. Audiovisual resources, such as slide projections, are also used.
During problem-solving exercises— which involve freehand drawing, the use of 2D and 3D CAD software, or calculations (in the case of tolerances)—the professor presents a problem and solves it, demonstrating the resolution strategy. Students then work on similar exercises within a set time, while the professor monitors progress and provides clarification. Once the time is up, the professor explains the solution and discusses alternative approaches. The modeling of parts or assembly models, as well as their graphical representation, is performed on the computer by both the professor and students.
Assessment includes two assignments—one individual and one group project—as well as a theoretical-practical test, allowing evaluation of students'' knowledge acquisition and the effectiveness of knowledge transmission throughout the semester.
Evaluation method
A portion (30%) of the final grade in the course unit (UC) is obtained through a theoretical-practical (TP) test, with consultation, to be taken individually by each student during the 13th week of the semester (May 26–30, 2025). Grades will be rounded to two decimal places, and passing the Theoretical-Practical Assessment component requires a minimum score of 9.50 in the TP test.
A second assessment component, accounting for 30% of the final grade, consists of an individual assignment (TI), to be completed and submitted by the 7th week of the semester (April 17, 2025). Each student must model and create a 2D representation of an intermediate-complexity part (>19 dimensions) from the set of parts approved by the professor for the final project. The submission must be sent via email to the professor of each group and include: the 3D CAD file (*.sldprt), the 2D CAD drawing of the modeled part (*.slddrw), and the PDF version of the 2D drawing.
The Final Project (PF) is mandatory and must be completed by groups of up to four students over approximately nine weeks of the semester, contributing 40% to the final grade. A project proposal must be submitted to the professor by the end of the third week (March 21, 2025).
The Final Project must consist entirely of parts and assemblies modelled after March 2025. Each student must model at least 10 different parts. Evaluation will be based on an oral presentation (10 minutes), followed by an individual discussion (10 minutes) with the professors. The presentation and discussion, which are mandatory, will be scheduled for the 15th/16th week of the semester. Failure to present and discuss the project will result in a zero (0) score for the Final Project component.
Final Project Evaluation Criteria:
- Technical accuracy, quality, and complexity of modelled parts – 25%
- Number of modelled parts – 10%
- Difficulty and effectiveness of assemblies – 25%
- Quality and presentation of the written report – 10%
- Technical accuracy and clarity of 2D drawings – 25%
- Organization and planning – 5%
The Final Project must be submitted by the 12th week (May 23, 2025) via email to the professor. It must include:
- Files of all modelled parts, assemblies, and the final assembly.
- 2D drawings of three modelled parts (one simple, one intermediate, one complex).
- The final assembly drawing, including the bill-of-materials.
- 2D drawings from individual assignments of all group members.
- The three group-drawn 2D drawings must be different from the individual ones.
- The final project report in PDF format.
The Laboratory/Project Assessment score is the weighted average of the Individual Assignment (TI) and the Final Project (PF). Passing this component requires a minimum score of 9.50.
A valid course unit completion (valid for one year) is achieved if the weighted average of the Final Project (PF) and Individual Assignment (TI) is at least 9.50.
Final Grade Calculation:
For Continuous Assessment:
NF=0.3×TP+0.3×TI+0.4×PF
(Approval requires NF ≥ 9.50)
For Retake Exam:
NF=0.3×Exam_Grade+0.3×TI+0.4×PF
(Approval requires NF ≥ 9.50)
Subject matter
1) Introduction to Computer-Aided Design (CAD3D and 2D): evolution, modelling and advantages. 2) General aspects of Technical Drawing: Standards, formats of papers, bill-of-materials, types of lines and their thicknesses, standard scales and writing. 3) Orthogonal projections. 4) Dimensions. 5) Creating, editing and modifying parametric CAD 3D models (solids and surfaces). 6) Detailed drawings, assembly drawing and revision of drawings, exploded view. 7) Drawing of machine elements and machine drawing according to standards. 8) Dimensional and geometrical tolerances. 9) Symbolic representation of surface finish and welding (CAD 2D). 10) Sheet metal technology. 11) Introduction to structural analysis by using the Finite Element Method (Solidworks Simulation) and Reverse Engineering (Solidworks ScanTo3D). 12) 3D printing (FFF and SLA).