The Definition of Terms & Acronyms Associated with 3D Printing
When we were first getting into 3D printing we found the number of acronyms & terms associated with the hobby of 3D printing to be very unfamiliar and nearly overwhelming. It seemed at first like we needed to learn an entirely NEW LANGUAGE.
Through reading a lot of websites & watching a lot of videos we finally learned the lingo – and we condense that all here in one easy to read post.
Here – we go through, define & explain the most common and important terms & acronyms related to 3D printing. We also cover a little 3D printer history and, finally, get you up to speed on this industry & hobby in one short post!
General 3D Printing Terminology: Acronyms & Terms
| ABS | PETG |
| CAD | PLA |
| CURA | RepRap |
| G-code | SLA |
| FDM | STL |
| FFF | Slicing |
| Filament | TPU |
| Marlin | IDEX |
| OBJ | |
| OctoPi/OctoPrint |
Parts of a 3D Printer
| Extruder | |
Slicing Parameters, Settings & Terms
| Layer Height | Speed |
| Infill / Fill Pattern | Temperature |
| Supports | Retraction |
| Rafts Skirts & Brims | |
| Rafts | |
| Skirts | |
| Brims |
3D Printing History, etc
| Definition of 3D Printing | History of 3D Printing |
General 3D Printing Terminology: Acronyms & Terms
ABS
ABS = (Acrylonitrile Butadiene Styrene) A type of filament used for 3D printing. Tough and durable – but also difficult to 3D print due to its tendency to warp. Does emit noxious fumes and VOCs (Volatile Organic Compounds). Not generally recommended for beginners.
CAD
CAD = Computer Aided Design. The use of computers running specialized software to design items for building & manufacturing. Allows the item to be rotated & manipulated in various means to aid the designer in visualizing & constructing the object or building. This is a primary way in which many models are built for 3D printing.
CURA
CURA = Open source 3D slicing software created by David Braam – and maintained by Ultimaker. It is genrally regarded as the Gold Standard in slicing software. It can be downloaded & installed for free from from Ultimaker’s website here.
FDM
FDM = Fused Deposition Modeling. This is a type of 3D printing that is most commonly seen at the consumer level and engaged in by 3D printing hobbyist. Plastic filament is fed through a heated nozzle (the extruder) and then deposited sequentially along the X & Y axis (horizontally in 2 dimensions) and then the next layer is printed on top of the previous layer. (adding the 3rd dimension)
FFF
FFF = Fused Filament Fabrication. Basically the same thing as FDM. The term FDM was trademarked (by Stratasys, inc) and members of the first open source 3D printer community (RepRap Project) came up with the alternative term FFF to avoid the legal issues with using the term FDM.
Filament
Filament = A slender wire-like fiber composed of various materials, but usually based on a variant of plastic (sometimes with other materials like wood or carbon fiber, etc added to it). The filament is what is melted by the head, or extruder of a FDM /FFF 3D printer and then output, layer by layer, to form the 3D object or model. For everything you need to know about filament please read my comprehensive post here: It’s All About the Filament.
G-Code
G-Code = The common name for the most widely used numerical control programming language used in computer-aided manufacturing. This code is predominately used to direct manufacturing & machining tools that are automated and controlled by computers. With regards to 3D printing, the slicing software generates this code to direct the 3D printer on the path it is to move the extruder and where it is to deposit melted plastic filament in producing a 3D model.
Here is what g-code looks like when it is opened up in a text editor:
IDEX 3D Printers
IDEX = Independent Dual Extrusion. An IDEX 3D printer has 2 separate printing, or extrusion, nozzles which allows the printer to INDEPENDENTLY & SIMULTANEOUSLY print 2 models at the same time. This, essentially, doubles the output of the 3D printer. The models that the IDEX 3D printer is printing at the same time can be either the same, or different. Likewise – the second extruder can be used to print with a different type of filament – or the same type but a different color. This might be useful to print out a model that needs to have supports – where the supports can be printed in water soluble filament to make the removal of the supports easier & quicker.
IDEX printers can be contrasted with DEPENDENT Dual Extruder 3D printers – in which the 2nd extruder is NOT able to operate independently of the first extruder. Dependent dual extrusion 3D printers are generally NOT able to print 2 different models at the same time (or even the same model – for the most part).
Dependent dual extrusion 3D printers are less expensive & more common, at the present time, than IDEX (Independent Dual Extrusion) 3D printers.
Marlin
Open-source firmware that drives most of today’s entry and mid-level FFF/FDM 3D printers. Created by Erik van der Zalm et. al in 2011 for RepRap and Ultimaker. It runs on the main board of the printer and coordinates all the real time processes of the machine – including the motors (steppers), display, buttons, heated bed, nozzle temperature, etc.
OctoPi/OctoPrint
OctoPi/OctoPrint = Generally used to refer to a device based on the Raspberry Pi that runs software to remotely control, monitor, and do time-lapse videos of your 3D prints. OctoPi is a Debian based version of Linux designed to run on the Raspberry Pi that includes OctoPrint. OctoPrint is the software program that actually allows you to interface, control, monitor and do the time-lapse videos of your 3D prints.
I LOVE our OctoPi – as it essentially added a host of new features to our Creality Ender 3 Pro – and made it much easier to use in our circumstance – where we were determined NOT to have the printer in our actual living quarters. If you want more information on how to set up your own OctoPi please click here to see my earlier post on how to set one up.
OBJ File
OBJ = One of the 2 primary file formats for 3D objects. OBJ files are not as popular or common as the STL format (the other primary file format for 3D objects) OBJ is a simple text based file format for 3D object files that typically contains more information about an object than STL. It generally contains information about not only the shape of the model, but also its geometry, texture, color and the original mesh that was used to create it. OBJ files are larger than STL files for the same object – since it includes additional information about the object above and beyond what the STL file does.
PETG
PETG = (Polyethlene Terephthalate Glycol) Used to manufacture water bottles. More durable than PLA, but not as difficult to work with as ABS. A good compromise/ middle ground filament. Does emit some noxious fumes.
PLA Filament
PLA = Polylactic Acid. The most popular type of filament used with FDM/FFF 3D printers. It has a relatively low melting point, is not prone to warping, adheres well to an unheated build plate, is non-toxic, and produces the fewest noxious fumes. This is the easiest material to succeed with and likely to cause you the fewest frustrations. So if you are just starting your 3D printing journey – the first filament type you should be using is PLA! It is made out of processed plant parts such as sugarcane & cornstarch which are organic materials
RepRap Project
RepRap Project = Replicating Rapid Prototyper. The RepRap was the first low-cost 3D printer and it ultimately launched the open source 3D printer revolution. The project started in England in 2005 as an initiative of the University of Bath to develop a low-cost 3D printer that could print most of its own parts.
SLA
SLA = (StereoLithography Apparatus) It is “other” type of 3D printing that hobbyist and consumers are generally less familiar with – as compared to FDM or FFF 3D printing. SLA, although an older 3D printing process, is not as commonly engaged in at a consumer level. It involves using a ultraviolet laser to polymerize a liquid resin (photopolymerization) layer by layer to form the 3D object. This type of 3D printing can produce a very fine level of detail – but there is a much higher level of post printing processing that needs to be done and the resin is considerable more tricky to work with as compared to filament for a FDM/FFF printer.
STL
STL = abbreviation for STereoLithography. It is the most widely used 3D printing file format today (2020). The file format was originally developed for 3D Systems by the Albert Consulting Group in 1987 as a means to transfer 3D models to their commercial SLA 3D printers. The STL file format generally only contains information about the 3D object’s shape – in contrast to the OBJ file format which contains information about the 3D model’s geometry, texture, color and the original mesh that was used to create it – in addition to the object’s shape. OBJ files are typically larger than STL files for the same object.
When people go to one of the many 3D model repositories such as Thingiverse, Cults3D or Pinshape – the are generally downloading STL files. It will be interesting as 3D printing becomes more ubiquitous and sophisticated to see ultimately which file format wins. I would expect in the not-to-distant future, that there will be more information regarding color and texture associated with the average 3D model as technology improves and features like dual extruders on FDM/FFF 3D printing machines become more mainstream!
TPU
TPU = (Thermoplastic Polyurethane) A very elastic & flexible material filament that is impact resistant & waterproof, but tricky to successfully 3D print. High “cool” factor – but probably not the best choice of material to work with until you have some experience printing other materials.
Parts of a 3D Printer
Extruder Assembly
The Extruder Assembly is the part of your 3D printer that draws in the filament and pushes it through a melt zone and then on to the nozzles / hot end to deposit the melted filament onto the print bed in successive layers to build your 3D model. On the “cold” side It has a motor and gears that control the RATE at which the filament is drawn into the assembly and the rate at which it is ultimately pushed through to the “hot side” of the melt zone and the nozzle – where it is discharged.
Slicing Parameters, Settings & Terms
Slicing
Slicing = Slicing for 3D printing is where you take care of setting up the mechanics of printing your 3D model. It is very similar to what is done through the printer dialog box when you are printing on paper with a regular printer. When you print something on paper – the printer dialog box is where you select your margin width, any scaling, type of paper, whether you want to print on both sides of the paper, and if so – how to flip it. In similar fashion, it is the slicing software for 3D printing – where you are setting a bunch of variables and parameters for printing your 3D object like the size of the print, the fill pattern, and the types of supports to use.
Layer Height
Quality (Layer Height): The smaller (or lower) the layer height – the better the print quality will be. However, the print job will be longer – since the printer has more layers to print.
Infill / Fill Pattern
Infill / Fill Pattern: – This is the inside of the model – the part you cannot see. It still affects the object – because it is a big factor in the rigidity of the object. The more infill – the heavier the object will be, more filament will be used (and hence the cost higher), and the longer the print time will be.
Supports
Supports: – When printing a 3D object with overhangs – it may be necessary for supports to be printed underneath certain areas of the model to prevent warping and distortion of the object during the printing process. Overhangs are when only part of a higher layer is supported by the previous layer. Remember – the 3D printer is essentially a giant (but sophisticated) glue gun – in that it is extruding a melted plastic – which has to cool somewhat before the extruded plastic provides any structural value. So stacking melted plastic hanging halfway off the previous layer of melted plastic will tend to distort and warp if the angle of the overhang is too great. It is generally recommended that for overhang angles greater than 45 degrees- that supports should be used. Type of filament, temperature, and printing speed may be other factors that influence whether or not supports are required for a successful print.
Rafts, Skirting & Brims
Rafts, Skirts & Brims: These are all strategies that involve putting layers of filament down on the build plate before printing the 3D model.
Raft
A raft is generally referred to as a horizontal layer of printed material beneath the actual model – so the 3D model is not resting directly on the build plate. It is used to help with build plate adhesion and stability of objects with smaller footprints. If your 3D model doesn’t adhere well to the build plate it is likely your build will fail – or at least be warped or distorted.
Skirting
Skirting is usually just a thin line around the object to be printed – and is done to essentially make sure that the extruder is hot enough, unclogged and ready to print. It’s like a warm up lap for the printer – to make sure it is primed and the filament is flowing properly. Think of a skirt as an outline of the object that doesn’t directly touch the object itself.
Brim
A brim is like a baseball hat brim – it doesn’t reside directly beneath the 3D model, but rather extends off the edges of the 3D printed object. It is primarily used to ensure the edges of the print do not come off the build plate.
Speed
Speed: Just like for printing a document – there is usually a compromise between speed and quality. So to with 3D printing. The quicker the printing process – the more compromise is made with regards to the precision of the print.
Temperature
Temperature: You can set the temperature of both the extruder (printing head) and the build plate. The temperature of the build plate is important in getting good adhesion of the 3D model to the plate – so it does not slip or move during the printing process – which would greatly reduce the quality and accuracy of the build, or might even lead to a printing fail. The temperature of the extruder will need to adjusted for different types of filament, and may need to be tweaked depending on speed of the print job or if you are experiencing clogging at the extruder.
Retraction
Retraction: Retraction refers to the distance the filament is retracted back (pulled back) into the extruder or printing head. Increasing the retraction can be one of the most important settings in reducing the strings associated with a 3D print.
Note – that it is the still solid and un-melted filament that is retracted from the melt zone in the printing head so that no additional melted filament is extruded through the print nozzle during non-printing moves. No melted filament is pulled, or sucked, back into the hot end of the printing head!
3D Printing History, etc
Definition of 3D Printing
3D Printing is the process of sequentially depositing small amounts of material in successive layers on top of each other. The printer essentially prints the first layer similarly to a regular printer (in 2 dimensions – with length & width, and only nominal height) and then prints the NEXT layer right on top of that previous layer. So with each successive (or incremental) printed layer, the height accumulates and the object begins to acquire its form in 3 dimensions.
While the printing of any single layer appears to only be in 2 dimensions (length & width) and does not seem to significantly contribute to the height of the object – the cumulative effective of the repeated process does! Similar – but the opposite of erosion!
You may hear 3D printing referred to as additive manufacturing – since it is assembling small amounts of material to produce an object – which is the opposite of manufacturing processes that start with a large chuck of material and scrape or cut pieces away to create the object (subtractive manufacturing).
A VERY Brief History of 3D Printing
In 1984 Charles Hull filed for a patent for a system of building an object, or model, in 3 dimensions using a process called stereolithography – which uses ultraviolet light to cure a photo sensitive resin of polymers layer by layer. In 1986 his company 3D Systems Corporation was granted a patent for this system and it produced its first 3D printer called the SLA-1 (SLA standing for StereoLithography Apparatus).
In 1988 S. Scott Crump took a different approach to 3D printing and developed a special method of extruding plastic that became known as Fused Deposition Modeling (FDM). He went on to become the founder of Stratasys and commercialized this method of 3D printing. In 1992 Stratasys sold its first FDM printer – the 3D Modeler.
In 2005 the University of Bath launched a project to develop a low cost 3D printer that could print most of its own parts. It was called the Replicating Rapid Prototyper. The RepRap ultimately launched the open source 3D printer revolution – and ushered in an era in which the consumer was finally able to get into this exciting new technology.
FDM printing became the most dominate form of 3D printing for the consumer & hobbyist markets soon afterwards. This was primarily for 2 reasons:
- FDM printers cost less to produce as compared to SLA printers, and
- FDM 3D printers were easier to operate & use at the consumer level when compared to their SLA printer counterparts.
Overtime, 3D printing has continued to develop in terms of sophistication and reliability. Significant advancements have been made with regards to the degree of precision in the printing process, complexity of objects that can be printed, speed with which things can be printed and the number of materials which can be used in the printing process – which now include metals.
Conclusion
If you have any suggestions or constructive input – please leave a comment below. Thank you!
Finally, I would like to mention that Hobby3DPrinting.com has recently been acknowledged as one of the top 100 3 Dimensional Printing blogs on the web by Feedspot. Thank you Anuj! We look forward to moving up the list as we grow our readership!
Sincerely,
