To this point, we have been focusing on the mechanics of choosing and using a 3D printer. However, the mechanics of using a printer to produce a good print is just a start. Deciding how to use the technology effectively is challenging, too. In this chapter, we discuss some issues common to most educational settings. In the remaining chapters of the book, we discuss particular opportunities and challenges for different disciplines and age groups.
Workflow
Most teachers have not dealt with digital fabrication tools (3D printers, CNC machines, laser cutters, and so on) before encountering them in a makerspace. Marketing videos usually show a time lapse of an object magically appearing on a build platform. The reality, though, is different. A modest print can take hours or even days, depending on the printer, the material, and the geometry of the print.
For filament-based printers, there are limits to how much faster the technology will get, based on physics. One layer has to cool enough for the next one to be laid down, and fans can only do so much. So these will always be slow. There are (currently exotic) techniques to do resin prints faster, but they are extremely expensive.
Time to Print
Most methods of one-at-a-time 3D fabrication are pretty slow, even for a professional practitioner. We talked about laser cutters and CNC machines versus 3D printers in Chapter 1 and will not repeat those tradeoffs here. Consider the time it might take for a person to carve the same shape with hand tools, and perhaps it might not seem slow at all!
Have each student make something small, and print them in batches. Because of the cooling-time issue, often several small objects take the same time to print as one small object.
Only 3D print what really needs to be 3D printed. If a student is making a sculpture that will stand on a big cube of a base, use something else for the base and only print the sculpture.
Have 3D printing as part of a group project, and have one 3D printed part per group. Ideally, have this project spread over several weeks or stagger group project stages somehow to spread out demand.
Teach good design practices that minimize support.
Have a review process that sends prints that will fail or use inordinate resources back to the student, with feedback and an opportunity for the student to fix the design problem. This also spreads out the load on the printers if a lot of prints bounce on first submittal, but overall class timelines will need to allow for this.
There are philosophical questions to consider, too. For example, will you allow a student to print something they have downloaded from a database and not changed in any way? Can they include such a file in their projects, or do you want to require that anything they print on a school printer has at least some original work? Or, perhaps, will you only allow them to print things they have designed from scratch? Are there things you will forbid your students to print? If you are new to this, you might check with a peer school that is ahead of you to see what has worked for them.
Print Queue Management
Short jobs cut the queue ahead of long ones.
Small jobs wait until they can be plated together and printed at once.
Risky experiments might wait until no class projects are due for a few days.
You will also need a way to track which prints are waiting to be printed, have been printed, have been attempted but have had the print fail, or have been rejected without printing for technical reasons. It is best to keep the sliced file until you are sure the print worked; otherwise you might need to waste time slicing it again if something went wrong (like a power outage) that does not require changing anything before printing again.
Finally, you will need to decide what to do about prints that take more than one school day. Will you allow overnight (or over-weekend) printing? If, say, the robotics team meets after school and only has a few hours, can they start a print and have it finish unattended? At any rate, you should get a fair amount of experience before leaving a printer unattended for any length of time so you know what will fail. You might come back to find a mess you have to clean up.
Many people put a webcam on their printer so they know if something has gone very wrong and can sprint over and deal with it. If you have a remote interface like Octoprint (Chapter 3), you can even stop the print remotely if you see that something has gone wrong. You will still have to remove the print and clean up whatever mess it made before you can try again, though.
Curriculum Issues
We are often asked where to find “maker curriculum” materials. We always find the request a little odd, because it seems to us that the right thing to do is to use tools like 3D printing to enhance learning in the typical subjects, rather than treat it like something to be learned per se.
Constructivist Seymour Papert famously suggested that student projects needed to have a low floor and a high ceiling, by which he meant that students should be able to at least get a toehold in a concept if they are struggling, but that there should be a lot of flexibility for stronger students to explore to the limits of their ability.
Right now, 3D printing’s “low floor” is seen as finding and downloading an existing model. This is unfortunately a common model of “using 3D printing in the curriculum.” We feel that designing a model—or perhaps altering ones that get you started—is where a lot of the learning takes place. For examples, see Chapter 9’s discussion about our science and math models and the philosophy behind them.
Except in some specialized cases (like teaching the visually impaired, as we describe in Chapter 12) just downloading a model and printing it probably does not add much value and is more or less a new version of ordering a model from a supply house. Database models can be misleading or represent a concept incorrectly, too.
So the question becomes: can students use Tinkercad, say, to have just a bit higher floor to visualize something they have just learned about, or to express themselves creatively? More importantly, how does doing this serve having them learn what they are trying to learn?
Currently, we are working on a project to reimagine calculus from zero and to create a hands-on version we call “Hacker Calculus.” It has become clear that to do it right one has to throw out the usual order of teaching. Time will tell how well this works!
What “Design Thinking” Means
Joan is trained as an aeronautical engineer and worked for 16 years as a rocket scientist. In that role she participated in many design meetings. Rich designed one of the earliest ancestors of today’s consumer 3D printers, as well as a modern consumer device. If you are teaching “design thinking” in a middle-school context, you may be confronted with many charts of the process that are wonders of color and complexity. Some we have seen would have given people planning missions to Venus pause, or made them roll their eyes.
Figure out what you want to do, or what problem you are trying to solve (without stating, yet, how you want to do it). Engineers call this “specifying requirements and not implementation,” which means: “Tell me what you need my design to do, and stop telling me how to do it.”
Think about what makes a design “the best” for this purpose and what “success” is and how to measure it. (Who decides what is “best”?)
Next, come up with some ways to do what needs to be done. Pick the one that seems “best” (given #2) and try it.
Did it work, by your definition of success? You are good! If not, roll back as far as you have to and try again.
Making the process itself something to learn, with terminology and vocabulary and many steps and arrows, seems to us to defeat the purpose of encouraging students to explore and prototype, and it can also intimidate teachers. Keep it simple and commonsense. Clear metrics of success can help with figuring out how to grade a project, too.
One reason why 3D printing and its sister digital fabrication technologies are challenging is that they require fluency in both digital design and the realities of what will happen when that design is created (or not) with an imperfect machine using real-world materials. The latter takes some amount of experience and willingness to live with failures along the way. Being able to live comfortably in both these worlds—to be able to design something that will actually work—will always be an in-demand skill and a key preparation for many STEM careers. But it requires an orderly approach and some discipline to get things to work.
It is still early days for us all to figure out the implications of this in the K-12 environment. For more on the big picture about 3D printing and the future workforce, see Chapter 14.
Summary
In this chapter, we discussed issues that arise in working with 3D printing in a school setting, including developing printing policies and workflows. Printer time needs to be managed, and makerspace managers must decide whether or not students need to develop their own designs, versus just printing something that already exists. We also considered how to make the concept of design thinking a bit less intimidating, and closed with some thoughts about the big picture of what students will need to learn now to be competitive in the world in which they will eventually work.