How did it start? A while ago I was telling my colleagues how cool the 3D printer I have at home is and how many things you could print with. My manager suggested getting one for the office and asked me which 3D printer to buy. I did a bit of research to see which one would best suit our office and our goals of improving the tech environment and we decided to buy a FDM printer.
A few weeks later the printer was on our desk in a big box. Everybody gathered round us while we were opening it and soon the printer was plugged in and waiting to be used. I did the whole setup very carefully, as I didn’t want it to fail while everybody was watching, then loaded up an .stl file and hit print.
And so it began… I decided that it would be a good idea to do a quick presentation and a workshop for those who were interested in this subject, before we started using it. That way I wouldn’t have to supervise everyone and it probably wouldn’t get broken. We then thought about what would help us to improve our work environment and decided to prototype some phone and tablet stands. We discussed the issues with the existing design, came up with an improvement, put it on paper, and then translated into a 3D model. A few hours later the prototype was ready to use.
Soon after that, we had a Hackathon coming up and one of the ideas we worked on involved 3D printing. A colleague came to me with the idea and we recruited a designer to help us create the 3D model from scratch. You can check the finished result here.
The best part of having this 3D printer is that it isn’t just for business use, you can just come in with a 3D virtual model and you can print it yourself.
What is 3D printing?
3D printing is the process of making three dimensional objects from a digital file. The solid object can be created using different processes like extrusion (laying down successive layers of material) or sintering (compacting and forming a solid mass of material by heat and/or pressure, without melting it). It is similar with two dimensions printing, but with an added third dimension, Z-axis.
How it works?
As the 2D printing starts with creating a “model” using a software, the 3D printing process starts the same. First you create and design the virtual 3D model on a computer. The model is created using a 3D modelling software (e.g. Solidworks, Catia, SketchUp) or scanning an existing object. Secondly you export it to a format that is compatible with the printer (e.g. *.stl, *.obj), and then the software slices the design into small horizontal layers that will be printed one on top of the other until the final object is done. Finally you print the virtual model into a solid object.
Almost all types of technology in the world have got multiple ways of implementation. And so does 3D printing. Not all 3D printers use the same technologies to build objects. The big difference is how the layers are created. Some of them produce the layers by melting or heating the materials. The most common technologies using this way of printing are Selective Laser Sintering (SLS) and Fused Deposition Modelling (FDM). Another method of 3D printing is using liquid resins that are treated using different technologies. An example for this method is called Stereolithopraphy (SLA).
Selective Laser Sintering – SLS
OWNER: Materialgeeza, used under Creative Commons license
SLS technology was developed and patented in the 1980s by Dr. Carl Deckard at University of Texas under DARPA’s sponsorship. It is based on a high power laser that heats the powdered material (plastic, metal, ceramic or glass) transforming it into solid shape.
The printer has 2 chambers, starting with one empty(A) and one full with powdered material(B). Once the process starts the roller moves one layer of powdered material from chamber B to A, and the laser fuses it by scanning the layers generated by the 3D modelling software. Then the platform is lowered by one layer thickness and another one is applied on top, with the process repeating until the object is created. The powder that is not touched acts like a support structure for the object. Remaining powder can be reused for the next print, so there we be no wasted material.
Stereolithopraphy – SLA
OWNER: Materialgeeza, used under Creative Commons license
SLA technology was developed in 1986 by Charles Hull who founded the company called 3D Systems.
This process involves a vat of liquid ultraviolet curable photopolymer resin and an ultraviolet laser in order to build the object layer by layer. The platform that will support the object goes down into the resin layer by layer while the laser beam traces the pattern on the surface of the liquid. By exposing the resin to the laser light will make it solid and so the object is created. The remaining resin can be reused for the next print, so there will be no wasted material.
Fused Deposition Modeling – FDM
FDM technology was developed in the late 1980s by S. Scott Crump, and commercialised in 1990.
This technology uses different types of filaments that are pulled from a spool into an extrusion nozzle. Once the material gets into the hot nozzle it melts and can be easily extruded into the desired shape. The extruder can move in both horizontal or vertical directions and so can the platform that supports the object (bed).
The final object is produced by laying down multiple layers one on top of another. The material hardens immediately after extrusion from the nozzle.
Everything starts with the computer, where you can create the 3D virtual model of the object and export it to a file. The file is then sent to a slicing software that interprets it and transforms to a gcode format that is easily interpreted by all 3D printers. Finally the printer creates layer over layer of the selected material and produces the solid version of the previously created virtual object.
In the last period a lot of different types of materials appeared for this printing technology. Starting from different colours of the same material to flexible or hard materials, you can choose whatever works best for your project.
Here is a small list of material types (description of the filaments from e3D-online):
PLA – PLA is a bioplastic usually derived from corn starches. PLA melts at low temperatures, has extremely low warp, bonds easily to cold bed surfaces, and generally prints with fantastic quality and no fumes. It might not be the best at demanding mechanical or thermal applications but it is cheap and easy to print with. The most popular polymer in 3D printing.
ABS – One of the most used plastics in our made world, ABS is a copolymer of Acronitrile, Butadiene and Styrene. Lego bricks, car dashes, and electronics enclosures all tend to be ABS. ABS provides a great balance of properties, while still being low cost enough for everyday use. Be aware that not all ABS is the same, and the properties from one ABS to the next can vary wildly.
Co-polyesters – PET, PETG and related Co-Polyesters present a great balance of printing much more easily than ABS, but having much better mechanical and thermal performance than PLA. They also come in crystal clear variants which have the best optical clarity in the plastics world.
Composites – Composite filaments are composed of a polymer binder with another material added to them to change their appearance and/or physical properties. This can take the form of attractive wood-like materials, where a binder holds together wood fibres, or specialist mechanical properties obtained by adding carbon fibres to a polymer binder.
Flexibles – Probably amongst the most fun filament types out there. These filaments are synthetic thermoplastic rubber-like materials. Great for useful products like gaskets, seals, shock absorbers, flexible hinges, and tyres. Also they’re great for just plain fun in printing various aesthetic models with a flexible twist.
Nylon – Nylons represent some of the toughest and strongest materials that can be printed. While they take a little more practice to print than other materials the rewards are huge. Interlayer adhesion is probably the best in the 3D printing world and tensile strength is fantastic. Nylons are relatively flexible and can be used for things like living hinges with long life. Nylon is also extremely low friction and makes for great bearings, sliders and gears.
Preparing for print
- Bed levelling:
- the printed part will stick better on the bed if levelling is done correctly
- once done properly will last for a while, depending on usage
- using a piece of paper of a known thickness
- feeler gauges, micrometer
- test prints and adjust the bed on the fly
- Cleaning the bed, degreasing
- Heating bed and extruder– depending on what material you are using you will need to use different temperatures for both the bed and extruder.
- Variables you can change before printing
- position of the object on the bed
- layer height
- printing speed
- cooling fan speed (PLA needs cooling fans, ABS doesn’t)
- infill percentage
- first layer settings
- skirt settings
- Printing sources – Depending on your printer model you can print from various sources like a computer, an SD card, your mobile phone or even from a file that is stored somewhere in the cloud
- End of printing – After the printing process is done you don’t need to fast remove the object from the bed, as you can easily break it. It is recommended to leave it for a few minutes while it is cooling down. By doing this will make it easier to remove it from the bed surface without damaging it. During the time after you remove the part, make sure that you clean and degrease the bed.
Usage of 3D printing
3D printing has been used in a lot of domains for decades, especially for designing and rapid prototyping of different objects. Until a few years ago these technologies were really expensive and slow, but now you can find a variety of models and prices. Prices can start from a few hundred pounds for a personal printer, to thousands for an industrial, really fast one. Depending on the needs you can buy what suits best for you or your business.
More and more companies are saving lots of money by using rapid prototyping using 3D printing technologies. In just a few minutes or hours you can check that your future product is exactly what you’ve created in the modelling software. With the advantage of having a variety of materials that you can use for printing, you can mimic everything. The quality of some of the printers is so good that companies are using them directly for mass production of the products and not just for prototyping.
Starting in 2011, 3D printing became popular for personal use. This happened mostly because desktop 3D printers started to become affordable in prices ranging from £250 to £3000 for high definition ones. You can use them to print small parts that you need around the house, or even as part of your hobbies (home made drones, robots or toys).
Do you have to be a 3D modelling expert to create 3D models? No, not at all. While complex and expensive CAD software like Catia and Solidworks have a steep learning curve, there are a number of other programs, many free, that are very easy to learn. The free version of Google SketchUp, for example, is very popular for its ease of use.
Thank you for reading!