Contrary to popular belief, 3D printers have been around for decades now. Even as early as 1980s, engineer and designers were using 3D printers at some of the leading technological corporations around the world. These commercial 3D printers cost tens of thousands of dollars and were an entirely different entity than the ones you can find today. Due to a patent expiry in the last 5 years, 3D printing has become much more affordable and has ushered in an era of “hobby” 3D printing. As the technology matures and more patents expire, 3D printing will become cheaper and much more capable than it is today.
What Is The Significance Of 3D Printers?
Traditionally, all of the manufacturing techniques that we use to produce mechanical parts are forms of subtractive manufacturing. We start from a solid block of material, and keep on removing bits and pieces until the final shape of the product emerges. This is the same form of manufacturing that was used in the Bronze Age to forge swords in the Turkish Empire. Subtractive manufacturing has been around since 3300 BC.
3D printing, however, is a relatively new and revolutionary concept in manufacturing. It is a form of additive manufacturing, which means that it deposits material, layer stacked upon layer, to create the final product. An obvious benefit of this is that less material gets wasted in the process. What is more exciting is that an entirely new class of material shapes can now be produced – think of complicated hollow structures. An application of this is to include cooling ducts directly into parts, which would revolutionize rocket technology!
However, in its current form, 3D printing is not perfect. The structures produced today are not as perfect, or as strong, as the ones produced by subtractive manufacturing. This can be accounted to the fact that whereas we have had millennia to perfect the forms of subtractive manufacturing, additive manufacturing is still in its infancy.
Our engineering capabilities have always been dictated by the manufacturing techniques, and every time a new method of manufacturing is discovered, it ushers in a wave of new technologies that were once deemed impossible. As we humans become more proficient with this new manufacturing technique, we just might have the next big Industrial revolution.
While being capable of such great feats, 3D printing is not as hard as it seems. In fact, many inexpensive 3D printers are available on the market today that makes it easy and affordable to familiarize yourself with the art of 3D printing.
How Do 3D Printers Work? What Are The Different Types Of Printers?
Before we delve into the world of 3D printing, it is useful to accustom ourselves with the jargon related to 3D printers.
- Filament: A material (usually plastic) shaped in the form of a wire. This material undergoes melting to form the layers of the manufactured part.
- Extruder: This is the device that heats up and melts the filament
- Nozzle: Thisis a small hole through which they push out the molten filament.
- Bed: The surface on which an object is printed. Sometimes you may use a heated bed to provide better adhesion.
- 3D Model: The 3D blueprint of the object to be manufactured
- G-code or machine language: Movement instructions that the printer follows to produce a part
- Slicer: A software program that translates a 3D model into G-codes.
- Axis: A reference line of movement. X-axis usually describes left-right movement, Y-axis refers to front-back movement, and Z-axis refers to up-down movement.
- Carriage: The moving part, which houses the extruder.
Types of Printers
There are two main types of 3D printers: Stereolithography (SLA) and Fused Deposition Modeling (FDM).
SLA printers consist of a liquid plastic called photopolymer resin. These use an ultraviolet light to cure (solidify) the resin in a vat layer-by-layer. These machines work from the top down, pulling the object out from the liquid.
Objects printed with SLA printers have high dimensional accuracy, intricate details, and a very smooth finish. SLA printers are usually capable of producing models faster than FDM printers. However, they are much more expensive to own and operate, and the models produced are much more brittle than the ones produced by FDM. Also, SLA produced parts are also susceptible to the UV radiation of the sun, so they cannot be used outside. This is the reason many beginners opt to go for FDM printers.
Fused Deposition Modeling (FDM)
FDM, also sometimes called Fused Filament Fabrication (FFF) is the simplest form of 3D printing. The filament is heated through the extruder and pushed out the nozzle. The nozzle and bed move in conjunction to produce the layers of the object. FDM machines work from the bottom down – the bottom layer is drawn, cured and then the next layer is drawn on top of the older one. Once a layer is produced, the bed is lowered slightly so that the nozzle is at the right height to draw the next layer.
FDM is one of the most cost-effective ways to 3D print an object. As a consequence, it has the lowest resolution and dimensional accuracy compared to other technologies. Usually, the lines of each individual layer can be seen after printing. These can be removed by different post-processing techniques.
Though FDM may lack the resolution and accuracy to be employed in a state-of-the-art manufacturing firm, it is usually good enough for most applications and is the best way to step your toes in the world of 3D printing.
FDM printers usually come in two different co-ordinate systems: Cartesian and Delta
A Cartesian co-ordinate system has 3 axes – X, Y and Z. The X and Y axes correspond to left-right and forward-backward movement, while the Z axis corresponds to the vertical motion of the machine. The nozzle usually moves in the X and Y axes while the bed moves in the Z-axis.
A Delta system also has the X, Y and Z axes. The difference is that in Delta systems, the extruder is suspended from three arms in a triangle arrangement. Each of these arms can move up and down independently. This allows the delta systems to print parts extremely fast. Some companies even boast that their delta printers can print parts upside down! We advise against doing so though, since the print quality often got affected in our experience.
Delta systems usually have a fixed small circular bed that makes them ideal for tall, narrow models. If you occasionally want to build something wider, we recommend going for a Cartesian system.
How to Step Into the 3D Printing World
Once you get your 3D printer, the next step is setting it up. Some models are very plug and play solutions, while some require a bit of manual setup. Different printers have different setup instructions, so unfortunately we cannot cover them all here. All models, however, come with detailed and easy to understand instructions for setup, so you need not worry. Once you setup your printer, it is time to print your very first object!
Obtaining the 3D model
To print your object, you first need the 3D model of it. These models can be designed in Computer Aided Design (CAD) software such as AutoCAD, Blender, SolidWorks, etc.
If your proficiency in CAD software is limited, do not despair. You can still print 3D models. There are a wide variety of freely available 3D models on websites like:
(This is not an exhaustive list. You can obtain and print 3D models from other websites on the internet provided that the design owner has given you permission to do so.)
Conversion to STL
Once you obtain the 3D model, you have to convert it into the STL format for printing. Thingiverse is one of those sites that allow you to directly download STL files. If you designed the model yourself, the software you used will have an option to export the file in STL format.
Conversion to G-codes
Once you have the STL file, the next step is to convert it into a form that your 3D printer can understand. Here is where a slicer comes in. A slicer can convert a STL file into G-codes. The manufacturer of your 3D printer may recommend a specific slicer or even include it with the printer. If not, you can use one of the many available on the internet. A few of the popular ones include:
There are many different settings you can set in your slicer, such as layer height, shell thickness, fill density, print speed etc. Follow the manufacturer’s recommendations till you get more familiar with these settings and what they can do. Then you can experiment and learn the effects of changing the parameters on the object. If in case you encounter any difficulty, the online 3D printing community is often very helpful. Browsing online forums can be a great tool to build your 3D printing knowledge.
Printing the object
Once you generate the g-code for your object, the next and final step is to upload it to your printer and print the model. This can be done either through a USB connection, or through plugging in an SD card to the printer with the G-codes on it. Keep in mind some objects take a long time to print. Your slicer will inform you of the estimated time to print.
Congratulations! If you followed the steps in the right order, you have your first 3D printed object. However, you are not quite done yet.
Post-processing is the final stage in 3D printing. Some of these post-print rituals are detailed below:
- Support Removal: Some designs incorporate supports to enable the printer to properly produce the desired part. After printing, these supports can be twisted or broken away.
- Sanding: Removing the support usually leaves marks on the print surface. Sometimes, lines of different layers are also visible. You can sand these artifacts away with a light sandpaper to produce a smooth finish.
- Painting: You can do this to alter the color of the model or to add protection to the print surface.
- Epoxy Coating: You can use this to smooth the surface of a part.
- Gluing: Sometimes you need to print a model in two or more parts when your printer volume is smaller than the volume of the object. In this case, you print all the parts and glue them together.
There, you are all done! Now you can go show off your first 3D printed model to everyone. With enough practice you can master the intricacies of changing the different parameters and, who knows, maybe produce your own 3D models for the whole community to enjoy someday!