3 d introduction

Editor's Notes

• #2: Instructor’s guidelines: Prepare in advance: Speakers (for embedded videos)
• #3: Instructor's guidelines: Begin the lesson by reviewing the traditional additive manufacturing process. Traditional additive fabrication began with clay coiling pottery around 2500 BC.
• #4: Instructor’s guidelines: The future holds innovative applications of 3D printing technology. Examples: human organs, food and buildings. This lecture will give an overview of existing technologies and where they may be headed. NOTE: You may refer to this Star Trek example. The replicator, first used only to produce on-demand meals, later took on many additional uses.https://www.youtube.com/watch?v=jp3OhC3NoMk
• #5: Instructor’s guidelines: Ask students: What is the difference between the definitions presented? Discussion: When the Wohlers Report added “layer upon layer” to their definition, how did that alter the meaning? Which definition is more general? After this discussion, which do you think better defines additive manufacturing? Which definition do you prefer?
• #6: Instructor’s guidelines: Ask students: What is the difference between the Wohlers Report definition of additive manufacturing and its definition of 3D printing above? Why does this 3D printing definition give more details about the how the technology works? Explain: While the terms are often used interchangeably, 3D printing is just one form of additive manufacturing.
• #7: Instructor's guidelines: Click to reveal the explanations. Emphasize:All 3 working aspects appear in various forms in all 3D printing technologies. There may be differences, for example, in slicing resolution, support material or fill options. Slicing: A 3D computer model is cut into horizontal slices (layers), in order to generate tool (extrusion) paths and calculate the amount of material needed. The CAM software slices the model according to the layer increments you specified in the modeler setup. Support: Ask students: Why do we need support material?Explain: We cannot print into open air because of gravity. Support material acts as scaffolding. If we look at the L-bracket again, both these orientations will allow us to minimize the z-axis. However, orientation one leaves plenty of open space that will require support. Fill: The density of the solid. Influences the characteristics of the final model including mass and design.
• #8: Instructor’s guidelines: Discuss this question with students.
• #10: Instructor's guidelines: Goal: To understand the evolution of design and production and gain a broad understanding of the advances that led to today’s manufacturing environment. To understand how the interaction between humans and our fabrication machines has evolved with the advancement of machine-readable design files. Explain: This is a Leonardo daVinci’s hand sketch of Codex Atlanticus. Leonardo is known for his detailed isometric sketches to visualize his ideas, From the details we can understand that daVinci aimed the product to be made out of wood, metal and robe.
• #11: Instructor’s Guidelines: Explain: In this image, we see how this designer used da Vinci’s sketch and 3D modeled it. This 3D-CAD render visualize the parts of the model but since it is computer model it can be assembled and modified.
• #12: Instructor’s guidelines: The 3D models designed from da Vinci’s sketches were 3D printed and made into physical product. Show the class this video demonstrating the 3D printed da Vinci system. The process of transferring design to manufacturing with CNC (Computer Numerical Control) machines is called CAD to CAM
• #13: Instructor's guidelines: Ask students: What is CAD? Click to reveal the definition. Explain: CAD software is used to: Increase design productivity Improve design quality Improve communication through documentation Create a database for manufacturing Enable easy modification and editing Enable easy navigation CAD software output is a digital file for 3D printing, machining or other manufacturing operations. In the following slides, we’ll learn about the evolution of CAD software.
• #14: Instructor's guidelines: Explain: Drawings were one of humanity’s first design tools. Ask the students: What are the advantages and disadvantages hand sketches for design? Explain: Original drawings must have been freehand, before tools like rulers, compasses and protractors. More modern drawings achieved more accurate scale and geometry using tools we developed. Modifying or re-drawing design was possible, but very complicated.
• #15: Instructor's guidelines: Explain: The introduction of the computer and design software has greatly advanced the design process. Ask students: How did computers solve some of the challenges of hand-sketching designs? What was the next step for designers and engineers after the creation of the first computers and 2D computer software? Explain: 2D software automatically calculated scale, which reduced the need for measuring tools. Because it enabled zoom-in and zoom-out capabilities, some say it improved designers’ ability to understand scale. Editing became easier and quicker with CAD software. Today, we can easily modify sketches, reuse them for different projects and copy-paste them from different software. Designs have become much more accurate. 2D CAD software had some design limitations, some of which still exist. For example, line weight can be modified easily. This can lead to geometrical misunderstandings when drawings are visualized.
• #16: Instructor's guidelines: Explain: So far, the final stage of the CAD evolution is 3D software. Ask students: Why would you want to design an object using 3D software instead of 2D software? What is the major contribution of 3D software? Explain: Not only does 3D software offer all of the 2D software advantages, but it also enables navigation inside the 3D world. 3D software lets us take 2D modeling and check the connections between different parts in the 3D world. There are many ways to simulate 3D models, including the use of mathematical equations. 3D rendering enables real-life visualization of the 3D model.
• #17: Instructor's guidelines: The first machines reduced human labor for simple tasks, but movement was controlled completely by hand, wheels and levers.
• #18: Instructor's guidelines: Ask the students: What are NC machines? In what way did they contribute to the work of designers and engineers? What technological stage was needed next? Explain according to the following comments: NC machines were the predecessor to today’s computer-controlled machines. They used punched cards to control machines axes. Punched cards served a purpose similar to today’s computer code. Movements were not entirely controlled by hand, so this reduced labor for some more complex tasks. Punched cards had to be programmed by a professional and shipped to the machine location, so it wasn’t remotely possible to go directly from a drawing to CAM.
• #19: Instructor's guidelines: Ask the students: What is a CNC machine? What are the advantages of this machine? In what ways did it contribute to the work of designers and engineers? Explain according to the following comments: CNC stands for computer numerical control. The machine itself has an electrical controller that controls the commands and the interface and sends feedback to the user. Most of the machines used today have a controller embedded inside them. This controller reduces the amount of human resources needed to operate the machine, enabling the machine to perform more complex tasks and to send a status update of the production, as well as feedback if something goes wrong. The controller uses codes in order to operate.
• #20: Instructor's guidelines: Summarize.
• #21: Instructor's guidelines: Ask students: How did people go from design to production when relying on hand sketches? How do we go from design to production in the era of CAD software? Click to reveal the process. Explain: Manual machines relied entirely on the fabricator’s interpretation of the sketch, if a sketch was used at all. NC machines needed humans to translate sketches into machine movements. CNC machines use code generated by computers to control machine movements. Typically, CAM software translates a CAD (design) file into a CAM (G-code) file. G-code is the most widely used CNC programing language. Used mainly in automation Also called G-programming language Tells the machine what action to take There are many different CAM software options. Today, each machine has its own software based on the G-code method.
• #22: Instructor's guidelines: Ask students: What is parametric design? How does it relate to this image? Click to reveal the relationship. Explain: Parametric design allows individuals (non-professionals) to be part of the design process. It re-introduces a human element lost with mass-production, but preserves automation. Because designers create the tools, they can build in the necessary production capabilities, essentially combining CAD and CAM functions. By including file-to-print code , they reduce the need for connectors and for saving multiple 3D files. Since CAM understands how the machine operates, we can create our own tool based on CAM, reducing use of the machine and fabrication time. Grasshopper 3D for Rhino 3D, Processing, Open S-Cad, Free CAD are examples of parametric design software.