3D printing is a revolutionary technology that enables the creation of three-dimensional objects layer by layer from digital models. This innovative process has diverse applications across various industries, including manufacturing, healthcare, automotive, and aerospace. Unlike traditional subtractive manufacturing methods, which involve cutting or moulding material to create a final product, 3D printing builds objects by adding material layer upon layer. This not only allows for intricate and customised designs but also reduces material waste. The technology has gained widespread popularity for its ability to produce prototypes, customised products, and even complex geometries that would be challenging or impossible with traditional methods. As 3D printing technology continues to evolve, it holds the potential to transform the way we design, produce, and distribute goods, making manufacturing more efficient and accessible. Read more for guide to 3D printing.
3D Printing Guide
Designing a model
Don’t fall into the trap of merely demonstrating the process by downloading and printing files from the internet. 3D printers can form an invaluable part of the design process, but you will need to be able to create 3D models using one of the many pieces of 3D CAD software that exist on the market if you are to get the most from your printer.
The good news is that the software doesn’t have to cost anything. There is a wealth of CAD tools available that are free to use and that will give you all the features that you will ever need. The other good news is that the days of needing high-powered workstation computers for CAD are also a thing of the past which means you have probably already got everything you need to start using this kind of software in your school.
If you have no CAD experience at all, Tinkercad is a great place to start. It runs in your browser window and allows you to “borrow” other Tinkercad users projects and modify them, which is a great way to see how others create 3D models and work your way up to creating your own designs from scratch. For those that fancy something a bit more high-end, have a look at Fusion360 – industry-level CAD software which still has a shallow enough learning curve to make it accessible to novices.
Time
The process of 3D printing is quite slow, especially when using the extruded plastic filament style machines which are the type most commonly used in schools. If you are creating a particularly large piece, it’s not unheard of for prints to take 20 hours and with a class of 20 students in a D&T workshop, you could be looking at weeks of print time to get through everybody. Because of this, it’s important to get your students to design objects that can be 3D printed in a set time frame.
The Airgineers Micro Drone project is excellent for this – frame designs can usually be printed in less than 2 hours.
Make parts, not entire objects
Once you have mastered CAD, it’s tempting to make some extremely complex models to print. However, 3D printers lend themselves to making parts much better than making entire objects. For example, if you were making an architectural model of a building, rather than trying to 3D print the entire design, use laser or hand cut modelling board for large flat expanses like walls, but use 3D printed parts for items such as corbels, buttresses, staircases or other intricate shapes.
Think about the process of 3D printing when you are deciding what is the best tool for producing your part. To minimise post-production work, you want your model to require as little support material as possible which can be helped by choosing the optimal orientation on the bed when printing the part or minimising the number of overhangs where the angles are greater than 45 degrees, since most printers can happily print 45 degrees or less with no support material at all.
A question of capacity
When selecting a 3D printer, the vast ranges of different machines and specifications can make choosing the right one a daunting task. One of the factors that needs to be considered is the build volume which controls the maximum size of object that you can produce. Printers with a bigger build volume tend to be more expensive but bigger is not always better, especially in a classroom environment. Sometimes, having a larger number of smaller machines can be more beneficial than one large one because whilst you can place lots of different models on a large bed to be produced at the same time, you need to wait until all the models have finished printing before the students can get their hands on their designs. Why is this a big deal? Because design is always an iterative process and you probably won’t get it right first time. By having a greater number of smaller machines, you maximise the amount of availability for starting new prints which means students can get their designs manufactured as soon as the next iteration is ready.
Get to know your 3D printer
Make sure you experiment with your machine so that you know how it is going to perform. This knowledge will help you to give good advice to your students when they are designing parts. How much shrinkage will they need to accommodate? What is the smallest wall thickness it can reliably print? It’s also a good idea to have a few ready-made example models which can be used to demonstrate how long a print of a given size is likely to take.
