Week 2 Computer Aided Design - CAD

This week we are going to explore differents CAD softwares

2D Softwares

In the case of 2D I evaluated two types of software, those that work with pixels and those that work with vectors.

Softwares that work with pixels, such as Adobe Photoshop, are based on transformations and arithmetic operations on the information of each pixel. We need to know that the images are an information matrix, of m x n x o, where m and n are the high and wide dimensions of the image, while o is the number of layers of the image, 1 for binary images and grayscale, and 3 for RGB. Each pixel contains a number that determines the intensity of the layer to which it belongs.


Softwares that work with vectors, as Adobe Illustrator, are based on dependent geometric elements that have properties of form and position, the greater advantage of this type of images, compared to the ones of pixels, is that its visualization is independent to the zoom, since that we can modify the size of the image without losing its quality.

3D Softwares

In the case of 3D, I evaluated three types of programs, those that operate based on operations, nurbs and sculpt modeling.

First kind of 3D software function by operation of adding (extrude or revolution of a plane surface), subtracting (cutting) and modifying the material, and are characterized by being parametric, this means that each operation can be modified regardless of the progress or its relations and interaction with other parts. You can modify in any stage of the design proccess, inclusive if you have already done the plans. I will show you later this software.


In contrast, NURBS (non-uniform rational B-spline) editors, such as Rhino, work by modeling surfaces defined by mathematical functions, which can be modified by control points. The advantage of this type of software is that they allow more free modeling. The way to make curves and vectors is the same that we used on Illustrator, only that in this case we can and need to close 3D curves to define a surface.


And finally sculpt modeling, like Sculptris, is based on the deformation of a base geometry body, like an sphere or a cube, by pressure and stretching operations. This is a much freer option in terms of forms, but much less accurate; this type of software serves to model characters and environments, but without being able to define exact measurements, more than a visual parameter.

2D Proccess

For the 2D CAD I chose Adobe Illustrator, in which I took tools like pen, the fill and stroke color boxes, the dropper, shapes and text to generate a basic sketch of the update of my project.

First I occupied the pen tool to generate all the contours of the sketch and with the move tool I adjusted the elements that were separated.

Then I filled the fill and stroke color boxes to define the color of all the elements.

And finally I took the tools of forms and text to indicate two important elements in the design: Number 1 points a handle that would work to lift the machine and to empty the contents, and the number 2 the mixer that is the main function of the machine.

3D Proccess

For 3D CAD I chose Solidworks, as I mentioned before it is parametric software, so it follows a logic of making a 2D sketch, modifying it by means of dimensions, and then occupying it in a 3D operation. There are two main operations adding or cutting material, which are implemented by extrusion, revolutionized, swept or matrices, in general terms; Then we have modification operations like chamfers, bevels, reinforcements, etc ... It is necessary to take into account that Solidworks is a very complete program, with which we can generate plans, assemblies, animations, rendered in addition to CAD.

In my case, I only used two of these processes: CAD and assembly, to get a general idea of ​​the 3D project.

As we can see in the following GIF the process I followed was as follows:

Open a new part file

Choose the extrude tool

Select a work plane

Draw a rectangle and modify its measurements

Draw a second superimposed rectangle

Remove all intermediate lines to clean the area

Specify a thickness

Draw a circle on the upper face of the cross and extrude it

Draw a smaller circle on the top face of the cylinder and cut it all over the piece

For the assembly process:

I finished modeling the other pieces

Open the assembly environment

Drag base piece to screen

We place a second piece and define the geometric relationships with the first piece to restrict movement. For structural elements 3 relations are defined so that it does not have any degree of freedom, whereas for movable pieces usually define 2 relations. These relationships can be between faces, axes and points.

At this point I can do a couple of motion tests.

This process is the one that involves 2D and 3D platforms to be able to generate files for the production of our model especially in low resolutions. This was my process:

I took Mun (my first sculpture model) and saved it in OBJ format

Open in 123D Make

Select construction technique: Stacked slices

Change the direction of the cutting axes to obtain greater clarity or in the position that most seems to us either for functional or artistic reasons

Get the drawings in EPS format

Open this file in Adobe Illustrator and at this point we could nest differently the vectors to optimize the material

Download Mun