You've may have seen the word CAD, but do you know exactly what it means to CNC?
CAD stands for Computer Aided Design or Computer Aided Drafting. CAD was developed in the early 60s. Today it is the premier way to design, develop and optimized products. People use CAD every day to design virtually every product you see. Generally, designers use CAD to design a product, and then produce prints to manufacture that product. A print is a picture of a part or assembly that is very exact. It includes the dimensions and a parts list used to manufacture a product.
CAD is the use of computer based software packages that assist engineers, architects and other design professionals in their designs. CAD is the part of the main designing process and involves both software and sometimes hardware. Current software packages range from 2D vector based drafting systems to 3D solid and surface modelers.
Computer Aided Drafting software packages can generally be broken into two groups. The groups are 2-D drafting packages or 3-D drafting packages. Most all software packages are moving to 3-D design. 3-D design is really the next generation of CAD. Utilizing 3-D design, engineers can make a model of their product. They can then look over this model for any apparent defects before it is ever made.
CAD is used to design, develop and optimize products. CAD is mainly used for the engineering of models and/or drawings of components. It is also used throughout the engineering process from concept to design of products. These products can be used by end consumers or used in other products. For example, you can design a bolt in CAD, and then use it in a Sub-Assembly in a planetary, which is a part of an earth-moving machine. CAD is also used in the design of tools and machinery. Finally, it is used in the design of all types of buildings from sheds to shopping malls.
Print Reading and DraftingWhen I went through college I learned how to read prints and draft. We had a bag of physical tools that we purchased and hauled around campus. T-Squares, French Curves, compasses, pencils and erasers filled this bag. Then you had a pad of drafting paper and a drafting desk. You would pin or tape the paper down and begin drawing or drafting.
Drafting paper has a grid to help keep you aligned as you began you design. In CAD, there is a grid you snap to, or guides to keep you straight. We had hard plastic templates to draw curves. CAD has numerous tools to draw curves and lines. We had calculators to figure out distances and ratios. CAD does this automatically.
Overall, you can view CAD as replacing Drafting. CAD moved the same type of process into a more flexible and efficient environment. CAD has also helped out with networking of designs. Different designers and engineers can work on the same assembly in different parts at the same time. This team effort really moves the overall process along much faster.
However, as far as print reading goes, that is about the same as it was before. Drafting outputs prints and CAD outputs prints. A human still needs to be able to read them and make sense of them. A plus with CAD is that it is much more standardized and clear. Many times before, prints were unique to their maker. Similar to handwriting, you could not always figure out what the engineer wanted to convey to you. CAD cleans all that up.
How do I translate my design into the computer?This is how I view CAD. You learn a CAD software interface and begin the translation of your idea into the computer. This usually takes some time and thinking. Many times your idea and design will be revised as you discover things you have missed. While you are translating, your idea begins to take shape. Now you can share it with others.
Different Design ViewsIn Drafting and CAD there are different views. These are viewpoints of your part or project from different sides. We need these different viewpoints to be able to describe our project accurately. Think of it like seeing an elephant from the front. You have no idea what the side or rear end of an elephant looks like. To be able to accurately convey the elephant to another person you need multiple views.
The main print or design views are:Front ViewTop ViewRight Side ViewIsometric View
