2. Computer Aided design¶
In the second week, we were focusing on 2D and 3D softwares to help us with our project. We have explored different softwares and websites.
Task 1¶
What is the difference between raster and vector?¶
Raster is made up of tiny squares which are made in a high quantity to form an image. The squares are also called pixels and the relationship between pixels and image is proportional which means more pixels provide higher quality. Adobe photoshop is an example of raster program.
Popular raster files: JPEG, PNG, and GIF images
Vector files does not include pixels unlike raster files. To produce an image they include mathematical equations, lines, curves with fixed points. Adobe Illustrator is an example of vector software.
Popular vector files: SVG, PDF, DXF
What is parametric design?¶
Parametric design is used in 2D and 3D softwares, it is a technique that allows engineers to use a set of parameters or variables to create complex products or structures. It can also be used for simple designs. For example, the designer can set a parameter called length and set its value as 10 cm, the designer can then use this paraameter to determine the dimension instead of inputing a value. There will be more explanation later on how to apply this technique for 2D and 3D softwwares.
What are the advantages of parametric design?
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Improving the overall design
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Effective
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Makes it easier to manage complexity
Task 2¶
2D and 3D design softwares¶
During this week it was required to explore at least two different 2D and 3D softwares to find out which software do we prefer. For 2D design I have used Cuttle.xyz and Inkscape. As for 3D design I have used Fusion 360 and TinkerCad. Each software has its own advantages and disadvantages so this task will focus on providing a brief description on how to use each software and how to use some essential features. Also, in the end there will be an evaluation of the softwares.
2D softwares¶
Cuttle.xyz¶
Once you open Cuttle’s website, you will get the below home page.
Then you will have to click on Create a Free Account
Once you click on Create Free account, you will then have to click on Create Account with Email
Then, you will have to log in with your email and you will get the below page.
Now, you can start creating your own design by clicking on New Blank Project
NOTE: with the free plan you can have 5 projects and 10 free downloads per month
Once you click on New Blank Project, the below page will open. This is the page where you can use your imagination to create and design different things
At the top you can see the menu bar where you can edit, share, modify your project.
File is used to export your design in different formats (SVG, DXF, PDF and PNG).
Edit is used to edit your design.
View is used to zoom in and out
Modify is used to use different features such as Boolean, mirror and merge paths.
Share is used to give you the option if you want to publish your design to the public or keep it private
At the left of the page, you can see the shapes that you can use to make your design and in the bottom you can see COMPONENTS note that you can create more than one component in one project.
At the right of the page you can see the steps you followed to create your design or the features you have used.
Cuttle works on dragging so you dont need to sketch by yourself, to design a rectangle you can follow the steps below:
First you need to change the units by clicking on Units & Settings
Then, you can choose the unit that you prefer.
Second you have to drag the rectangle, you can place it no matter where and you can change its dimensions either by clicking on the width or length dimension (black arrow) or by changing x and y values in the scale (red arrow)
To create my own design, I have researched a 2D design online and then started creating it. You can see the final sketch below.
To start my sketch, I dragged the circle and changed its dimension to 100 mm
Then, I have fill it with grey by clicking on Fill at the bottom right of the page
After that, I dragged a second circle and changed its dimension to 40 mm. Then I have highlighted the two circle to make the small circle exactly in the middle.
Then, I have fill the small circle with blue color
After that, I used the Rotational repeat feature to draw the circles. To achieve this, I clicked on the small circle then modify and then rotational repeat.
Once I clicked on rotational repeat the circles automatically appeared on the big circle.
It is shown in the above picture that some sides of the circles intersect which migh create some difficulties when using the laser machine for cutting. So, I used the Boolean feature. To do so, I clicked on rotational repeat > modify > Boolean Union
The result will be shown as the below picture
After finishing your design you can then export it by clicking on File > Export DXF
click here to download my original file design
How to add a new parameter in Cuttle?¶
To add a new parameter you simply click on + and add the name of the parameter and its value.
Now, if you want to change the dimension of a rectangle for example, you just have to write the name of the parameter.
Inkscape¶
The second software that I have used is Inkscape and to use it. I had to download it from the website.
Step 1 I opened the website and clicked on DOWNLOAD NOW
Step 2 clicking on msi
Step 3 clicking on Next
Step 4 clicking on Install
Step 5 I opened the App and then clicked on Save
Step 6 I have clicked on Print
Step 7 Then I have clicked on A4 Landscape
Step 8 I have used the rectangle tool to draw a rectangle
Step 9 I changed the dimensions of the rectangle by changing its length and width
Evaluation of 2D programs¶
After using both cuttle and inkscape software. I have the impression that cuttle is easier to use and it is suitable for beginners who wish to start their designs. Also, in case of printing cuttle is the better option as it provides exporting the files as DXF files unlike Inkscape. On the other hand, Inkscape is better for professtionals as it provides more tools and features and it is more complex. The good thing about Inkscape is that it is completely free and it is easy to download it and does not require a license or registration.
3D softwares¶
Fusion 360¶
Fusion 360 is one of the recommended programs for 3D designs. It provide a trial of 30 days and after one month it needs a paid subscription. So, to use fusion I had to download it. For the 3D design, I thought of trying fusion by sketching a laptop. Below is the final sketch and all the steps will be explained later.
First, before sketching you need to make sure that you are using the proper units. This can be achieved by clicking on Document settings > Change active units > millimeter
Step 1 under SOLID I clicked on Create Sketch then I chose the plane on which I want to draw my sketch and finally I have changed the dimensions of the rectangle. You can change the dimension just by clicking on the value the change it.
Step 2 clicking on Finish sketch
Step 3 I have used Extrude feature to make it 3D.
Step 4 to sketch the screen I draw a smaller rectangle in the same plane
Step 5 I have used Extrude to make the frame of the laptop
NOTE I changed the direction of the feature by clicking on the blue arrow in the middle.
Step 6 on another plane I have draw the base of the keyboard and then extrude it
Step 7 I have created a skitch on the keyboard base and used to extrude feature to get the below image
Step 8 I have used the fillet feature to round the corners the avoid sharp edges.
Step 9 I have selected the edges and changed the radius to the desired value
Step 10 To create a text in an image I clicked on create > text
You can see below the 3D model
click here to download my original file design
How to add user parameter in Fusion¶
Step 1 Click on modify > change parameters
Step 2 Click on the add icon > add expression and value > ok
Step 3 Now, you can use the parameter instead of specifying the dimension you just have to write the name of the parameter
Tinkercad¶
The second 3D software that I have used is Tinkercad and it is easy to use. First you need to sign up if you dont have an account or log in if you have one. I clicked on log in since I already have an account
Then, you have to click on create > 3D Design
To start sketching, you simply can drag the shapes
Evaluation of 3D programs¶
After using both Fusion 360 and Tinkercad I would say that I prefer using Fusion as it is more complex and can give me the ability to design whatever I want and by various features. It supports STL which is considered as an advantage. However, it is not free after one month so in my opinion this might be the only disadvantage. It was my first time to use Fusion and before I tried other 3D software which is SolidWorks and for me SolidWorks is easier than Fusion. When it comes to Tinkercad, I think it is program for absolute beginner and people could use it for fun and it provides circuit designs which I think is a good thing and it is free.
Designing a part related to my final project¶
In week 1 I have explained how would my final project looks like and I have selected rack and pinion for the horizontal movement of the football net. So, I have used Fusion to design the rack.
Step 1 I clicked on UTILITIES > ADD-INS > Scripts and Add-ins
Step 2 Click on Spur gears
Step 3 Change the values
NOTE I have not changed any value beause to determine these parameters I need to specify the size of the goal and the force needed which is not done yet. Once I take into consideration all the aspects I can easily just change the values.
You can see below the 3D model