Computer Aided Design

Main Information

What is CAD?!

CAD (Computer-Aided Design) refers to the use of computer software to create 2D drawings and 3D models. These tools allow designers to simulate, modify, and develop designs before manufacturing. CAD drawings are digital representations of objects created through technical plans, offering higher precision and detail compared to traditional hand-drawn technical drawings.

The following software tools were used and learned during this week. This experience was highly enriching. To compare the 3D modeling software, I decided to design the same chess piece (a pawn) in all three programs. For 2D graphic software, I used different reference images to explore and test their available tools.

Softwares en 2D

Inkscape

Inkscape is a free and open-source vector graphics editor that uses the Scalable Vector Graphics (SVG) file format. It has a simple and intuitive interface with a wide range of tools that allow highly precise drawings.

How to use Inkscape – Step by Step

1. Open the program and select New Document.

2. In my case, I used an image and converted it from pixels to vectors. To do this, I selected File → Import and chose Embed image so it remained within the file.

3. I selected the image, right-clicked, and chose Trace Bitmap. I used the Multiple scans option with color detection to generate several vector objects from different color levels. Increasing the number of scans resulted in a more detailed image.

4. Finally, I modified the colors according to my preferences.

Affinity

Affinity Designer is a graphic design software that allows photo editing, vector design, and publication layout. It offers a professional workflow with advanced tools.

How to Use Affinity Designer – Step by Step

1. Open the application and create a new document with the desired size.

2. Import a reference image using Ctrl + O and reduce opacity to 35% to use it as a guide.

3. Use shape tools for basic geometry and the pen tool for complex shapes. Remove excess areas with the knife tool.

4. Group objects using Ctrl + G and apply colors.

5. Export the final design using File → Export and configure the desired format.

Softwares en 3D

To compare the three 3D programs, I modeled the same chess pawn in each one, using different techniques and tools.

Blender

Blender Blender is a free and open-source software used for 2D and 3D modeling, animation, simulation, and rendering. It allows the creation of complex geometries and provides a wide variety of tools for detailed modeling.

How was the piece built? Step by step

1. Open Blender and delete the default cube. From the top menu, I selected Add, which displays a list of geometric primitives, and added a cylinder. Using the side panel, I adjusted its position so it was placed on top of the plane and modified its size. Then, I duplicated this cylinder and placed it on top of the first one.

2. I switched from Object Mode to Edit Mode, selected Face Selection, and chose the top face of the upper cylinder. Using the Scale tool, I reduced the size of this face by scaling from the white circular handle until the desired proportion was achieved.
3. Using the Loop Cut tool, I created a cut in the middle of the piece. To smooth the edges, I applied the Bevel tool and configured it with 22 segments. Increasing the number of segments results in smoother edges but increases rendering complexity. After this, I returned to Object Mode.

4. I added a new cylinder and adjusted its dimensions to match the size of the object below it. This cylinder was duplicated and scaled to create the curved body of the chess piece.

5. Another cylinder was created with similar dimensions and elongated using the Scale tool. Then, I added an additional cylinder and scaled its top face to make it wider.

6. I added a final cylinder, reduced it to the required dimensions, and applied beveling on both faces to obtain the desired rounded effect for the piece.

7. Finally, I completed the model by adding the remaining elements required to finish the pawn geometry.

8. To add textures, I switched to the Shading tab and enabled the Node Wrangler add-on by navigating to Edit → Preferences → Add-ons and activating it. Then, in the Material section, I added a new material, selected the green shader node, and pressed Shift + Ctrl + T to load the texture files. The textures used in this project were downloaded from Poly Haven

OnShape

OnShape is a cloud-based CAD system that operates on any device. Since it runs entirely online, data is not lost. It offers multiple advantages, such as no required installations, the ability to work on designs through simultaneous collaboration, and access to a wide range of advanced features. The software is completely free, although creating an account is required.

IMAGEN

Additional information can be found here:

How was the piece built? Step by step

1. First, access the Onshape website and log in to your account.
2. Select Create and then Document to create a new part. In this section, the document name can be assigned. Once completed, select Create.
3. The main interface will appear, displaying the reference planes. A new sketch was created, and the plane to work on was selected. In my case, I chose the Top plane.

4. I began by creating a circle starting from the center. Dimensions were then assigned. Once completed, the green checkmark was selected to save the sketch.

5. If unit changes are required, the menu icon with three horizontal lines can be selected to display additional options. From there, Workspace units can be chosen and adjusted according to preference.

6. The Extrude tool was selected, along with the sketch to be extruded, and the desired dimensions were applied.

7. Another sketch was created on top of the extrusion, where a circle was drawn, dimensioned, and extruded again. To create the curvature of the pawn, a new sketch was made by selecting the Right plane. Working only on half of the axis, the Line tool was used to draw a straight line at the top with fixed dimensions. Then, the Spline tool was used to create the pawn’s curvature.


Finally, a straight line was added to close the sketch. Once completed, the Revolve tool was used by selecting Surface, the curve to be revolved, and the axis (circle) around which the revolution was performed.

8. The same previous steps were repeated, modifying the curvature as required.

9. In a new sketch, a straight line was drawn to create a solid base beneath the previous components. A new plane was then created on top of this base to model the remaining parts of the piece. This process was continued until the rest of the pawn was completed.

10. To create the head of the pawn, the arc or spline tools could have been used; however, the circle tool was chosen as it provided a simpler approach. A straight line was then placed through the center, and the excess portion of the circle was trimmed in order to perform a revolution.

11. To add textures, in the Parts section, right-click on the part to display the options menu. Then select Assign material and choose the desired material.

SolidWorks

SolidWorks is a 3D design software used for creating parts, assemblies, and simulations. It provides a comprehensive set of tools that enable efficient product development and design optimization. A license is required to use this software.

Additional keyboard shortcuts can be found HERE!

How was the piece built? Step by step

1. Open SolidWorks and create a new part document.

2. A sketch was created in the Front Plane. The design process began with simple shapes, which were later refined. Construction lines were added as references. A circle and two rectangles were created, and the Spline tool was used to connect the geometries. Straight lines were then added to close the shape. Half of the sketch was trimmed, leaving only one side for a revolution operation.

3. The completed sketch was selected, the Revolve feature was applied, and the central axis was chosen to generate the 3D geometry.

Compress images and videos

Compress videos with FFMPEG

To compress images and videos, I used FFMPEG

Basic Commands

1. Download Windows builds by BtbN. Once the program was downloaded, a folder was created on the computer’s main hard drive. The compressed file was then extracted, and the files from the folder named bin were copied.

2. The following path was accessed: System Settings → Advanced System Settings → System Properties → Environment Variables. Once the Environment Variables option appeared, a new variable was created, and the directory path of the corresponding program folder was added. The changes were then confirmed.

3. Open Command Prompt and run FFMPEG from the terminal.
4. In my case, I added the path to the folder where my video file was located and executed the following command:ffmpeg -i NOMBRE DE VÍDEO -vf “scale=-2:720” -c:v ibx264 – preset slow -crf 30 -pix_fmt yuv420p -movflag +faststart -an NOMBRE DEL ARCHIVO.mp4

5. Finally, the video was compressed from 5,199 KB to 238 KB

Compress images with Inkscape

I found very useful using Inkscape to compress images and it is simple to use. I had to follow the next steps:

1. Open Inkscape and import the image you want to compress.

2. Go to File → Export As → Export PNG.

3. In the export dialog, adjust the DPI and compression settings. Also, don't forget to change the type of image's format for the one you prefer.

4. Click Export and save the compressed image. In this way, you can observe that I reduced the size of the image from 65 KB to 38 KB.

Project Design

1. I decided to begin with the robot chassis. For this purpose, I used Onshape. I opened a new document and created a sketch using the dimensions I considered appropriate.


The sketch was then extruded to create the base of the structure. At this stage, the chassis was designed to allow proper assembly.


2. Next, a curvature was created on the same plane to form the walls of the robot chassis. The previously defined geometries required for assembly were respected.


In this step, the Spline and Line tools were used to draw the profile. Finally, this sketch was extruded to a thickness of 5 mm.


3. The same procedure described in the previous step was repeated on the opposite side of the plane.

4. Afterwards, the curved shape of the top cover was drawn using the Spline tool and extruded.


However, instead of using a solid extrusion, the Thin option was selected, and the direction and depth of the cover were configured accordingly.



And that's it

Simulation

For the simulation, I designed a camshaft in SolidWorks. The process I followed was as follows:

And the result of the simulation is shown in the video above.

If you want to access to my work from this week, please click here to download!