This weeks project is all about using computer aided design (CAD) to create a part that is of moderate complexity, whilst doing so we must document our progress. We should also aim to make use of parametric designs and explain how doing so using parametric CAD software. The software I am going to use is Solidworks for this CAD model.
First, I have decided that a good example of an object that would require a parametric design is a gear/cogwheel, therefore this is what I am going to be modelling.
An example image of gears, taken from: https://basic2tech.wordpress.com/2015/12/17/gears/
Progress update 1 for the cogwheel: I have modelled the main body of the cogwheel so far, but have not begun to model the teeth, so I guess it is just a wheel as of right now.
Cogwheel progress 1
Progress update 2 for the cogwheel: I have begun modelling the teeth of the cogwheel. I did this by creating a 3 point arc and setting the dimensions for the height, width and radius and then mirroring it about a centre line.
3 point arcs being mirrored.
Next is to extrude cut through the entire cog, this will be the base of our teeth.
The first tooth in the cog.
Now in this next part is when the main use of parametric CAD comes into play. This step requires me to create a circular pattern of the teeth the entire way around the cogwheel. This needs to be perfectly equidistant for the cog to function correctly, therefore using the pattern tool allows me to do so.
The cogwheel with the circular pattern tool showing where the cuts for the teeth will be placed.
This is the final outcome of the cogwheel. I am pretty happy with how it came out, it is also to the correct scale for the size of the cogwheel.
The finished Cogwheel.
Other examples of CAD can be called ‘assemblies ‘. Assemblies are multiple parts put together to show how the parts go together. This helps to determine if the parts fit together correctly as well as giving an idea of the final project once all the parts are together. A simple example of an assembly I have is th TIE fighter assembly from a different part of this project. In the image below it shows the separate parts and then the fully assembled model using an assembly.
The cockpit section and main body.
One of two wings.
The final assembly of the TIE fighter.
Another very useful feature found within CAD is the ability to accurately measure and set the scale of any measurement you choose. This allows the user to create to scale models with ease. In solidworks, it is called Smart Dimension, and it will become your best friend whilst using the software. It can be seen in the images below.
Here the size of the wing edges and middle hole can be seen in milimetres.
Again, the scale of the cockpit is shown using the Smart Dimension tool.
