3D Printing and Manufacturing

In this step, we are going to discuss the use of 3D modelling to create your embedded system. We will give you a brief introduction to the process and introduce you to some simple tools to get you started.

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3D Manufacturing

The 3D printing industry has come a long way in a very short time. Only three years ago, 3D printers were still out of reach for most people. Now it is possible to buy a 3D printer for your home that costs less than most mobile phones. Digital Trends has written this article describing the best options for cheap 3D printers.

You don’t even have to buy your own 3D printer; there are numerous services that will print your designs and post them to you. Have a look for services close to you, using services like makexyz.com.

Lots of areas also have public makerspaces, and most will have a 3D printer you can use. If you can’t find one in your area, check out our course on starting one for yourself.

Tinkercad: The Simplest Tool for the Job

There are a few choices of free 3D modelling software. One of the most popular is Blender. If you have some experience with 3D modelling you should be able to pick it up with relative ease; otherwise, it can be a bit daunting.

For this course, we are going to focus on a simpler tool that is free: Tinkercad. Created by Autodesk for use in education, it is a surprisingly powerful tool with an approachable interface. Tinkercad comes with its own free tutorials to help get you started.

3D Design

Two Halves Make It a Whole Lot Easier

The design you make should have two pieces: a base and a facade. That way you can place your components inside before closing it. It also means that (assuming you haven’t glued it together) you can reopen your device if you need to fix or change a component.

As with all designing, it is best to start on paper.

The Base

Begin by making a footprint, which is the base of your design. You need to ensure that all the components can fit inside the footprint. A good method is to represent each component with a piece of paper that you can easily move about to try out different arrangements. Make sure each piece of paper is the correct size and shape for the component (you may have to scale it down for larger projects). You might have to measure your components, but most of them will have technical documentation online that will include their exact dimensions. Once you have the layout you can start 3D modelling this part of your design.

Some designs will require you to create a hole in the housing for the components to fit into exactly. This is much easier if you have a model of the component to work with in your software. If you have chosen components that are widely available, chances are that someone in the maker community has already created a model for it. You can check sites like Thingiverse or YouMagine for the models you require. If you can’t find them, you may have to make one. You could then share it so that others can use it in their designs.

You can then use the models to ‘cut’ the shapes of the components from your design, creating perfect slots. A word of caution: 3D printers are great, but not perfect. Make sure you leave some tolerance by making the component models slightly bigger than their actual size.

The next stage in this process is to create the facade of your housing. This is the user-facing element: the top of your box or the face of your watch. This is the only part of the design a user will see, so take some time to make sure you get it right.

The final consideration is how you will fasten the housing together. Screw holes can be incorporated into the 3D model, and a threading tool can be used create threads for the screws. You could use strong rare-earth magnets, which are available cheaply online, though this may not be feasible for outdoor devices or wearables. Again, you will have to include holes for the magnets and then glue them in place. You can also glue the housing together, if you are confident you will not have to take it apart.

Your Turn

Use the Tinkercad tutorials to learn about the basic features of the program.

Create one of the following designs to share with your fellow learners:

• A boat, using this project
• A smartwatch housing for a micro:bit, using this model created by Kitronik
• A housing for one of the devices you have worked on so far (if you feel particularly confident)

How did you find using Tinkercad? What did you like about it? What were some of the challenges you encountered?

Share some pictures of your work and your thoughts on Tinkercad with your fellow learners.