Idiot's Guides: 3D Printing (2015)

APPENDIX C

Further Uses of 3D Printing

You’ve read through this entire book and even managed to reach the final appendix! Obviously, you just can’t get enough of 3D printing. Luckily, there are a lot of uses for 3D printing I haven’t gone into yet. Some of these require more than just a regular 3D printer, while others are very new and experimental ways of using a 3D printer. Whatever the case, most of these will also require additional research on your part. But this should give you an idea of some more things you can do with your 3D printer now and potentially in the future.

Your 3D Printer as an Intermediary Process Tool

One way to take advantage of your 3D printer is to use it as an intermediary for other creative processes. Think of it like how you use a mixer before using the oven when you bake a cake. The 3D printer becomes just one tool in the process instead of doing everything. Using this approach, you can get around the limitations of 3D printing, especially when it comes to material options and producing large quantities of parts.

Investment Casting

Investment casting is an extremely old manufacturing technique. It’s the process of making a part, surrounding it with a mold, and then pouring molten metal into the mold to reproduce the part. The reason it’s called investment casting is because the original part is lost during the process and the mold cannot be reused.

Traditionally, investment casting was done with a wax original part. The wax was easy to work with, melted easily, and was cheap, allowing a person to make an intricate metal part by first working with wax. Investment casting was (and is) very popular for making jewelry.

But astonishingly, 3D printers are almost perfect for this process as well. You can design a part in CAD, 3D print it in PLA, and use that printed part for investment casting. The melting point of PLA is low enough that it’s suitable for investment casting.

With this process, you don’t need a wildly expensive SLS 3D printer to make metal parts. Instead, you can just use your inexpensive hobby printer to print PLA parts, and then use investment casting to make metal parts. This is a method that has been proven to work very well and is actually relatively inexpensive.

So what do you need to actually do this? Well, first you need a way to melt the metal, which is a job handled by a foundry. Aluminum foundries can be made at home for less than $100. You’ll also need a handful of basic tools and safety equipment for handling the molten metal. And finally, you’ll need some casting sand for making the molds themselves.

All in all, you can pretty easily get set up for investment casting for just a couple hundred dollars. Home metal foundries are usually only capable of handling aluminum (which has a relatively low melting point), but that’s good enough for most hobbyists.

A whole book could be written on investment casting alone, but the basics are easy enough to understand:

· Once you’ve printed a part in PLA, fill a container about halfway full with your casting sand. There are many formulas in use for the sand, but it’s generally normal sand mixed with some sort of binder, like plaster.

· Push half the part into the sand, making sure all of the crevices of the part are filled in.

· Fill the rest of the container with sand, with a sprue (which forms a channel) for pouring the metal and another to vent the air and gases as the metal is poured.

· Once the casting sand has had time to set (the time frame will vary dramatically depending on the sand formula), remove the hardened block of sand from the forming container.

· Using the foundry, melt the metal (usually aluminum for hobby casting) in a crucible. Once it’s molten, it can be poured into the opening formed by the sprue. As it’s poured in, the molten metal will melt away the original PLA part.

· After the metal has cooled, the block of sand can be broken apart, and the metal part can be removed for finishing.

It may take some practice, but soon you’ll be able to make your own 3D metal parts at home!

Mold Making and Resin Casting

3D printing is great for making a few parts, but what if you want to make many copies of the same part? Investment casting destroys the original part and the mold, so it’s not a good option if you want multiple copies. This is where mold making and resin casting come in. They allow you to make many copies of a part by simply pouring molds. This is a more time- and cost-effective method of creating duplicate parts than simply 3D printing them.

The first way to go about this is to 3D print the mold itself (which is the negative). This will require you to either use mold-making tools in CAD or manually model the mold in CAD. With a model of the mold, you can simply 3D print it like any other part.

A one-piece mold for making a chocolate bunny.

Once you have your mold, you can use common hobby casting materials to make your parts. However, not all materials will be suitable, because some will stick to the mold. But many materials (such as silicone) can be used.

All you have to do is pour the liquid material into the mold and wait for it to set and cure. Depending on the material, this could take anywhere from a few minutes to a couple of days. Once it’s cured, you can just pull it out of the mold and start a new part.

The other way of casting adds an extra step but has a number of benefits. For this process (often called resin casting), you print a normal part on your 3D printer exactly as you normally would. You then use a flexible silicone mold-making rubber to make a mold around the printed part (the positive). After the silicone has cured, you can remove the original part and begin casting new parts by pouring resin into the silicone mold.

The benefits of the resin casting method are twofold: you can make many molds from a single printed part which can be used simultaneously, and your final parts can be made from a variety of materials. With the resin casting method, you can make your final parts from materials like polyurethane, which is incredibly strong—and much stronger than the original printed part.

Using Your Printer for Good

But maybe you’re not just looking for another way of making parts. Maybe you want to do a little more, and maybe you’re even feeling philanthropic. As luck would have it, 3D printing can help with that, too!

Charity Work

One of the most exciting things 3D printers are being used for right now is charity work. One use in particular has grabbed the attention of many people: 3D printing prosthetics.

Traditionally, prosthetics have been very utilitarian and rather unwieldy. They’re expensive and tend to be ill-fitting and difficult to use. Custom prosthetics have always been much better, but they’re even more expensive and aren’t usually covered by medical insurance.

That’s where 3D printing has come in. Under the direction of organizations like e-NABLE (enablingthefuture.org), 3D printer owners have been able to give a hand to those in need—literally. People with access to 3D printers can 3D print prosthetic hands and give them to the people who need them.

All of the parts needed for a prosthetic hand, ready to print.

I can’t overstate how revolutionary this is. The prosthetics themselves are rapidly becoming more and more advanced as they’re developed further. They can be customized to fit the user perfectly. And, perhaps best of all, they’re very inexpensive to 3D print.

This has allowed those who have lost limbs to get high-quality prosthetics for free. And those prosthetics aren’t junk either; in most cases, they’re much better than the prosthetics they would have received through traditional avenues.

Perhaps most importantly, the e-NABLE project is hugely beneficial to children. Because children grow so quickly, it’s difficult for them to get prosthetics that fit them as they grow. But now they can receive new 3D printed prosthetics that fit them perfectly as they get older.

So if you have any interest in giving back, I highly recommend you look into this project (and others). With just a little bit of your time and few bucks worth of filament, you can really make a difference in someone’s life.

Hackerspaces

If the idea of getting involved in making things with other people appeals to you, consider joining a local hackerspace (hackerspaces.org) or makerspace in your area. Hackerspaces are basically small community workspaces where members can use a variety of tools for their own personal projects. The idea is pretty simple: tools are expensive, so why not share them?

Most big cities in the United States have one or more hackerspaces, and it’s likely there is one in your area. To join, you usually pay a monthly fee to gain access to the hackerspace. Once you’re a member, you’ll have access to a wide range of tools like 3D printers, CNC mills, laser cutters, welders, carpentry tools, and so on.

Additionally, this will give you a place to congregate with other like-minded people. You can collaborate on projects, get help with challenging problems, and take classes to expand your skill set. Some hackerspaces are focused on particular topics (like electronics or metal working), while others are more general and have a little bit of everything.

If you do join a hackerspace and have a 3D printer, it’s certainly worth considering bringing your 3D printer. They do use membership dues to purchase tools, but hackerspaces are expensive to run. A lot of the tools there are owned by members or were donated by members. Whether you decided to bring your 3D printer or not, hackerspaces and makerspaces are a great way to get involved with people in your community.

Potential Applications for 3D Printing

So far, I’ve talked about things you can use your 3D printer for. But maybe you’re interested in learning about some experimental uses of 3D printing currently in development. If so, there are many interesting applications for 3D printing that are currently being explored.

For now, these uses of 3D printing are still experimental and under development, but the possibilities for improving people’s lives are very interesting. They’re still very new, but as these technologies mature, you’ll start to see how they can truly affect people’s lives around the world.

Printing Food

FFF is unique among 3D printing technologies, because the same basic concept that allows an FFF printer to extruder molten plastic can also work for any other material that can be liquefied and then solidified. If a substance can be liquefied, squeezed out of a nozzle, and then solidified, it can theoretically be 3D printed using the FFF printing process. That can even include food.

Why would anyone want to 3D print food? Right now, my impression is that it’s mostly a matter of novelty. But there are some reasons why it could be more than just a curiosity. One example of this is wedding cakes. Anyone who has ever had to shop for wedding cakes knows that intricate detail in the decoration is highly sought after. Those decorations are carefully crafted by hand by the baker, which can be difficult and time-consuming, which means it’s expensive.

But what if those intricate decorations could be 3D printed? It’s possible to use an FFF 3D printer to extrude icing onto a cake and to create complex decorations with the icing. In fact, it’s already been done. Icing is stored in a tube which can be compressed to squeeze the icing through a nozzle. Just like with a standard FFF printer, the icing can then be layered to create 3D designs.

Cake decorations are just one example of 3D printing food, and admittedly it’s not likely to change the world. But what if 3D printing could be used in an unconventional way that does have the potential to change the world?

Creating Buildings

If you’ve ever seen a new building being constructed, you know it can take weeks or months. First, a foundation needs to be poured. After that, a frame has to be constructed, walls must be added, a roof needs to be built, siding has to be added, and so on. It’s a lengthy and complicated process, and a lot of labor is needed for the construction. But what if buildings themselves could be 3D printed?

That’s not only possible, but it’s already been done. It’s still very experimental, of course, and is mostly being done to test the idea. But it is being done, and the idea has been proven. The process works by extruding concrete, layer by layer, to form the structure of the house.

The idea of 3D printing houses or other buildings has tremendous potential for changing the world. For one, automating the process of construction means the labor needed is greatly reduced. Also, a large-scale 3D printer can also run all day and night, reducing the time it takes to construct a building.

The possibilities are almost limitless for this technology. Strong and durable homes can be built quickly and cheaply without skilled labor. By mounting the concrete extruder on a crane, the potential size of the 3D printed building is almost completely unrestricted. Building plans can be easily reused, reducing the time and cost of designing them.

You can probably easily imagine the implications in third-world and developing countries. Long-lasting homes and buildings could be constructed quickly and efficiently, making a big difference in countries where families can’t afford homes constructed using traditional means.

The potential for improving the living conditions of people around the world is fantastic. But what if 3D printing could go even further? What if it could actually save lives?

Making Organs

Even the wealthiest countries in the world struggle with providing adequate health care to their citizens. One complication in particular is holding back medical care: organ transplants. Two problems make organ transplants especially difficult: finding organ donors and rejection of the transplanted organ.

Finding an organ to transplant is problematic for obvious reasons: it requires a donor. For some organs, like kidneys, the donor can be alive, but most people aren’t eager to part with their organs. For others—like hearts, for example—the donor has to be deceased. In both cases, it’s difficult to find a donor. Even if a donor is found, blood types have to match between the donor and the recipient of the transplant (among other requirements).

After all of that has been done, it’s still possible for a transplanted organ to be rejected by the recipient. The human body just isn’t too accepting of tissue that originated in another body.

Luckily, researchers think 3D printing can solve both of these problems. The idea is that tissue is harvested from the patient’s own body and used as the material to 3D print a new organ. This means a donor isn’t needed, and also means that the patient’s body is likely to accept the new organ. This possibility alone is enough to revolutionize medicine, but it doesn’t stop there.

When pharmaceutical companies test new drugs or treatments, they need something to test them on. Traditionally, this is done on animals or human patients, which can be risky for both. But if living tissue can be 3D printed, it would be possible to ethically test drugs without the risk of harming any humans or animals. It also means tissue can be printed with a specific condition that the drug is designed to treat.

For example, if a pharmaceutical company wanted to develop a new treatment for cancer, they could 3D print tissue with cancer. That would let them test the treatment on real human tissue that has cancer without risking the well-being of an actual cancer patient. Done on a large scale, this could dramatically reduce the time it takes to develop a new drug while simultaneously increasing the effectiveness of that drug.

About the Author

Cameron Coward is a mechanical designer and 3D printing enthusiast. As a mechanical designer, he has extensive experience with CAD, 3D printing, CNC milling, and traditional manufacturing. On his self-run website, Serial Hobbyism (serialhobbyism.com), he uses his professional and personal experience to teach readers everything they need to know about starting new hobbies. When he’s not writing, Cameron can be found working on projects in his workshop or in the mountains of Colorado.