In this Introduction to Computer Aided Design, you will find a set of topics with a systematic content ("How to" short videos, a "vade mecum" of best practices, an assignment with the 3D models required to achieve the tasks, and further tutorials to carry on your learning of CAD fundamentals). The CAD modeller PTC Creo Parametric was used to create most illustrations (videos, photos, files, etc.), so you should better stick with CREO to practice, but some aspects, such as "vade mecum" are software-agnostic, that is, you can apply the tips with any CAD software (Catia, Solidworks, etc.). Each topic ("Solid Modelling", "Assembly Modelling", etc.) are independent of each other, but if you are new at CAD modelling, you should better follow the topics linearly from top to bottom.
- CREO settings
The "CREO Settings" section aims at teaching the basic set up settings of CREO Parametric. An unusual feature of CREO Parametric is the management of both volatile memory (session) and non-volatile memory (P:).
- Solid Modelling
The "Solid Modelling" section aims at teaching the basic CAD operations for modelling solid bodies. We strongly encourage you to start watching the set of short "How to" videos with PTC Creo Parametric open so as to reproduce the operations. Once you have got the gist of solid modelling, you shall carry out the assignment. If the assignment is too difficult, you can follow the tutorial "Extra work - Modelling a piston", else you can go further by following the tutorial "Extra work - Modelling complex parts with patterns".
- Sheet Metal Modelling
Sheet Metal Modelling
- Assembly Modelling
The "AssemblyModelling" section aims at teaching the basic CAD operations for assembling solid bodies. We strongly encourage you to start watching the set of short "How to" videos. Once you have got the gist of assembly modelling, you shall carry out the assignment. If the assignment is too difficult, you can follow the tutorial "Extra work - Working with assemblies".
- Parametric Modelling
The "Parametric Modelling" section aims at teaching the basic CAD operations for modelling parametric solid bodies. We strongly encourage you to start watching the set of short "How to" videos. Once you have got the gist of parametric modelling, you shall carry out the assignment.
- Technical Drawing
- Kinematic Analysis
- Dynamic Analysis
- Export geometry as .STL file
Export geometry as .STL file
To export a part in the STL format for 3D printing, make sure to custom the output settings as shown in the video "How to - Save as STL file". By setting the "Cord Height" to 0 and the "Angle Control" to 1, the cord height will automatically change from 0 to the lowest acceptable value. The lower the chord height, the finer the triangle will be; consequently, the larger the size of the output file.
- Chord Height is the maximum deviation between the designed part and the STL representation of the part. This deviation is measured in the native units of the part, so the maximum absolute deviation in the above file is about 0.0869mm. Since an STL file approximates your part’s surface geometry using tessellated triangles, there is a tradeoff between accurate representation of curves and the number of triangles used. The larger the number of triangles, the larger the file size.
- Angle Control sets the amount tessellation that take place in curves of a small radii. The greater the tessellation, the greater the file accuracy which in turn increases file sizes. This value can be set between 1 (most accurate) and 0 (least). Change this if the default results are not satisfactory.
- Step size controls the maximum triangle size in the part which has a similar implications to Angle Control and Cord height. The smaller this figure, the finer the tessellation will be.
- If you are printing an Assembly en-bloc, please ensure your assembly is fully regenerated by clicking t Regenerate and that the configuration of your assembly is according to your design intent. Interfering components will be printed conjoined into one piece and moving components require the appropriate allowance with other.