Login

Introduction to CAD and 3D printing

Objectives

  1. Introduction to Fusion 360
  2. Overview of the basic functionality of  Fusion 360
  3. Introduction to various types of Additive Manufacturing (AM)
  4. Understand the reasons for the popularity and advantages of AM

Things

For this project, you will need

  1. Autodesk Fusion 360 on your computer

Let’s begin!

Historically, developing customized designs and novel mechanisms have been a cumbersome and time-consuming process. However, with incredible advances in the fields of Additive Manufacturing (AM) technology and Computer Aided Design (CAD) in the past 10 years, this is not the case anymore. Today rapid prototyping has become incredibly efficient and accessible, allowing us to create and test whatever we choose to imagine. However, to leverage the power of this technology, we must learn about some useful tools for 3-D modelling and design.

Computer Aided Design (CAD)

One of the most popular tools is Fusion 360, which is offered by Autodesk. The best part is that there is a free version for students and educators. In the first post, let’s take a look at how to download the software and explore some basic features.

1. Go to the following link: Download

 

Fusion 360 download page

 

2. Click on create account and fill in the relevant details. A confirmation email will be sent to your account, following which it will be approved.

3. Sign in, and follow the on-screen instructions to download the student version. The download should begin automatically as shown.

4. Once downloaded, install the software by following the instructions and using default settings. Launch the application once prompted.

 

Fusion 360 opening screen

 

Fusion360 is a CAD/CAM software that operates on a cloud-based platform, which means you need an active internet connection to use it. You can do 2D/3D modelling, analysis and simulation among various other features that we encourage you to explore. For this course, we will limit ourselves to the entire process of CAD modelling up to 3D printing the model. We will guide you through the various features of the software as we start modelling some useful designs. We will be designing two models, one static component and one movable component which uses Fusion 360’s inbuilt Physics engine to visualize the motion of the part while you design.

Some commonly used tools in Fusion 360 include:

  1. Drawing tools: These allow you to create a new geometry in the sketch domain, including custom lines and common shapes. E.g., line, circles, polygons.
  2. Editing tools: Make changes to existing geometry: erase, trim, undo, redo, mirror, split, etc.
  3. 3D/solid modelling tools: Allows you to convert a 2D geometry into 3D using tools like extrude, revolve, hole and modify it using options like fillets, chamfers, push/pull etc.
  4. Rendering tools: Ability to selecting the lighting, texture, mapping, custom material selection etc.
  5. Analysis: Static stress analysis, thermal analysis, vibrational analysis, etc.

Additive Manufacturing

3D printing in recent times has gained increasing popularity due to the following main reasons among various others.

  1. Faster production
  2. Cheaper
  3. Better quality prototypes
  4. Cost effectiveness
  5. Creative designs and freedom to customize
  6. Less waste production

3D printing has been around for many years but didn’t really take off until 2010. Here are commonly used 3D printing techniques that are used in the industry today.

1. Fused Deposition Modelling (FDM)

An extruder nozzle attached to a mobile frame will move along the bed of the printer depositing a suitable material layer by layer to construct the required object to be printed. ABS, Polycarbonate  (PC) and Polylactic Acid (PLA) are some commonly used materials. This course will explore FDM printing to print the models designed.

     Points to note

  • Developed and implemented first time by Scott Crump, Stratasys Ltd. founder, in 1980s.
  • Also called Fused Filament Fabrication (FFF).
  • Builds parts with production-grade thermoplastics, so components printed are of excellent mechanical, thermal and chemical qualities.

     Process

 

Fused Deposition Modelling process

 

  • The printer heats thermoplastic till its melting point and extrudes it through the nozzle on to the bed.
  • The nozzle and the bed follow calculated path during printing.
  • Once the layer is finished, the bed is lowered to start building of the next layer.
  • This continues till the 3D printing of the component is completed.

2. Selective Laser Sintering (SLS)

A pulverized polymer is fused together in the desired shape, layer by layer by a laser, in accordance with the CAD model designed by the user. The excess powder is brushed off after the printing is done.

     Points to note

  • Developed by Carl Deckard, a student of Texas University, and his professor Joe Beaman in 1980s.
  • Uses high-powered laser as power source to form solid 3D objects.
  • Uses powdered material in the vat instead of liquid resin as Stereolithography (SLA) process does.
  • Does not need to use any support structures as the object being printed is constantly surrounded by unsintered powder.
  • Offers a high design freedom, high accuracy and produces parts with consistent mechanical properties.
  • The material to print with might be anything from nylon, ceramics and glass to some metals like aluminum, steel or silver.

     Process

 

Selective Laser Sintering process

 

  • The powder bin and the build area are first heated just below the melting temperature of the polymer and a recoating blade spreads a thin layer of powder over the build platform.
  • A CO2 laser then scans the contour of the next layer and selectively sinters (fuses) the particles of the polymer powder. The entire cross section of the component is scanned, so the part is built solid.
  • When the layer is complete, the build platform moves downwards and the blade re-coats the surface. The process then repeats until the whole part is complete.

3. Stereolithography (SLA)

It is a combination of photo chemistry, lasers and software to create the desired geometry. A liquid photo polymer is solidified upon exposure by a UV laser. The UV light is directed so as to trace the design. This method produces one of the highest accuracies and surface finish.

     Points to note

  • Patented by Charles Hull, co-founder of 3D Systems, Inc in 1986.
  • Oldest method in the history of 3D printing.
  • Converts liquid plastic into solid 3D objects.
  • SLA  works with photopolymers.

     Process

 

Stereolithography process

 

  • SLA machine exposes the liquid plastic, and laser starts to form the layer of the component.
  • After plastic hardens, a platform of the printer drops down in the tank a fraction of a millimeter and laser forms the next layer.
  • Once all layers are printed, the object is rinsed with a solvent and then placed in an ultraviolet oven to finish processing.

4. Digital Light Processing (DLP)

     Points to note

  • Created by Larry Hornbeck of Texas Instruments in 1987.
  • Converts liquid plastic into solid 3D objects.
  • DLP  works with photopolymers.

     Process

 

Digital Light Processing process

 

  • This process uses digital micro mirrors laid out on a semiconductor chip and a conventional source of light such as arc lamps.
  • The material to be used for printing is placed in the transparent resin container.
  • The resin hardens quickly when affected by large amount of light.
  • When the layer is finished, it’s moved up and the next layer is started to be worked on.

5. Selective Laser Melting (SLM)

     Points to note

  • SLM started with German research project held by group of Fraunhofer Institute ILT in 1995.
  • Forms 3D object by means of a high-power laser beam that fuses and melts metallic powders together.
  • Metals that can be used for SLM include stainless steel, titanium, cobalt chrome and aluminum.
  • The applications include manufacture of aerospace and medical orthopedics.

     Process

 

Selective Laser Melting process

 

  • The fine metal powder is evenly distributed on to a plate.
  • Each slice of 2D layer image is then intensively fused by applying high laser energy that is directed to the powdered plate.
  • The energy of laser is so intense that metal powder melts fully and forms a solid object.
  • After the layer is completed the process starts over again for the next layer.

6. Polyjet

     Points to note

  • PolyJet builds parts with photopolymer resins.
  • Only technology capable of printing multiple materials simultaneously.
  • Achieves complex shapes, intricate details, and delicate features.
  • PolyJet 3D printers use fine printhead nozzles to deposit droplets of photocurable liquid material onto a build tray in layers as fine as 16 microns.

     Process

 

Polyjet process

 

  • The jetting heads deposit a single layer of the build material (typically photopolymers) by sliding to and fro along the X axis.
  • As soon as the droplets of these liquid photopolymers are jetted, they are immediately cured and hardened by an UV light.
  • Once a layer is complete, the build platform drops along the Z axis, and the next layer of photopolymers is ejected from the heads.
  • The process is repeated till the object is complete.

7. Electron Beam Melting (EBM)

     Points to note

  • Originally coined by Arcam AB Inc. in the beginning of this century.
  • EBM is another type of additive manufacturing for metal parts using an electron beam.
  • The material used in EBM is metal powder that melts and forms a 3D part layer by layer by means of a computer, that controls electron beam in high vacuum.
  • Contrary to SLM, EBM goes for full melting of the metal powder. The process is usually conducted under high temperature up to 1000 °C.
  • Currently the most well spread materials that are used for EBM are commercially pure Titanium, Inconel 718 and Inconel 625.

     Process

 

Electron Beam Melting process

 

  • The metal  powder is deposited in the form of thin layers that are preheated and melted layer-by-layer.
  • A high energy beam consisting of electrons (rather than photons in laser sintering) is used to solidify the metal.
  • These solidified layers are then built up until the completed part is finished.

8. Laminated Object Manufacturing (LOM)

     Points to note

  • Developed by the California-based company Helisys Inc.
  • Layers of adhesive-coated paper, plastic or metal laminates are fused together using heat and pressure and then cut to shape with a computer controlled laser or knife.
  • Post-processing of 3D printed parts includes such steps as machining and drilling.

     Process

 

Laminated Object Manufacturing process

 

  • LOM printers use continuous sheet coated with an adhesive, which is laid down across substrate with a heated roller.
  • The heated roller that is passed over the material sheet on substrate melts its adhesive.
  • Then laser or knife traces desired dimensions of the part.
  • Also the laser crosses hatches of any excess material in order to help to remove it easily after the printing is done.
  • After the layer is finished, the platform is moved down by about one-sixteenth of an inch.
  • A new sheet of the material is pulled across substrate and adhered to it with a heated roller.
  • The process is repeated over and over again until 3D part is fully printed.

 

Now that we have some basics set, let’s head straight into the CAD modelling software to create our first design.

 

Takeaway

Loader Loading...
EAD Logo Taking too long?
Reload Reload document
| Open Open in new tab

 

 

SEE ALL Add a note
YOU
Add your Comment

We would love to see what you build out of these learnings!

Click here to submit your projects, share it with the world and stand a chance to be rewarded.

top

Knowledge and Content by Li2 Technologies | © 2021 NASSCOM Foundation | All rights reserved

X