3D Printing Glossary
GZERO Additive Academy
ABS
Acrylonitrile Butadiene Styrene (ABS) is one of the oldest 3D printing filaments and is known for having good strength, impact resistance, and temperature resistance. Considered a prototyping grade material, it is also useful for functional parts that will see moderate loading and temperature fluctuations. ABS is used for many injection molded consumer goods including LEGO bricks, suitcases, and automobile bumpers. ABS also pairs very well with HIPS support for dual extrusion 3D printing of complex and detailed parts. ABS releases fumes during the printing process that are best handled by a multi-stage filter such as the BOFA PrintPRO 3D.
Baby Stepping
Baby stepping is the fine adjustment of the distance between the nozzle and build plate on the first layer. Ensuring the nozzle is the correct distance from the build plate is critical to achieving a good first layer and good bed adhesion. See also Z Offset
Bed Adhesion
One of the most critical aspects of FFF 3D printing is making sure that all areas of the printed part stick to the build plate (bed) and remain stuck throughout the duration of the print. The better the bed adhesion, the better the part will stick to the build plate. There are a variety of surfaces, coatings, and adhesives on the market specifically to manage 3D printing bed adhesion. “Bed adhesion” and “first layer adhesion” are used interchangeably.
Build Plate
A 3D printer build plate is the flat platform that the printed part builds off of. In FFF printing, as with most other printing technologies, the first layer of the part prints directly onto the build plate. Build plates are usually heated to help prevent printed parts from warping. “Build plate”, “bed”, and “print bed” are often used interchangeably.
Bridging
FFF printers have the ability to span unsupported gaps over cutouts in parts. This is referred to as bridging. Bridging typically involves altering the print speed, extrusion multiplier, and part cooling fan speed. Relying on bridging instead of support is a great way to reduce print time, material usage, and post processing time when the bridging surface is not critical.
CAD
Computer Aided Design (CAD) refers to a computer program used to generate designs. For 3D printing, we are interested in 3D designs (or 3D CAD programs). “CAD files” output from a CAD program contain a virtual 3D representation of a part. “3D model” and “CAD file” are often used interchangeably. The STL file type is the CAD file most often used for transferring data from a CAD program to a slicer for 3D printing. All modern 3D CAD programs can output STL files. For beginners, we suggest Ashlar-Vellum Xenon as it is a very capable 3D CAD program and is available for a reasonable price.
The typical 3D printing software workflow is as follows: CAD file (typically STL file) goes into slicer, slicer generates gcode, gcode file is uploaded to machine
Dual Extrusion
Some 3D printers (such as GZERO Additive models with “Dual” in the name) contain two or more extruders. These machines can produce dual extrusion prints that use more than one material to build a single part. Dual extrusion is typically used to build complex parts that require support. Dual extrusion support structures will be printed with a material that is easy to remove from the main part and/or is easily dissolved away from the main part material. Common dual extrusion material parings include ABS with HIPS support, PETG with PVA support, PLA with PVA support, and PETG with PLA support.
Extrusion Multiplier
FFF 3D printers extrude a filament feedstock through a hot nozzle, depositing material where instructed in order to build a part. Due to variations in material stiffness, diameter, and friction, the rate at which material flows through the nozzle will change slightly. Extrusion multiplier is a slicer setting that corrects for this on a material by material basis. Increasing the extrusion multiplier increases the amount of material that the printer deposits. Decreasing the extrusion multiplier decreases the amount of material that the printer deposits. This setting is usually adjusted by one or two percent at a time.
FDM
Fused Deposition Modeling (FDM) is a trademarked term for making a physical representation of a graphic design by a material deposition process. The first company to commercialize this type of 3D printing, Stratasys, still owns the trademark and therefore no other company can sell FDM machines without licensing said trademark. The desire to not pay Stratasys lead to the widespread adoption of the name Fused Filament Fabrication (FFF) to describe this type of 3D printer.
Filament
3D printing filament is the feedstock that FFF 3D printers use to build parts. Filaments are usually thermoplastics and include a wide variety of materials and colors for different uses. Some filaments are filled with glass fiber or carbon fiber for added strength and durability. Other filaments are filled with metal, ceramics, Kevlar, and other engineered materials for specific applications. 3D printing filaments are available in two main sizes, 1.75mm and 2.85mm (sometimes called 3mm) diameter. GZERO Additive 3D printers use 2.85mm diameter filament.
Gcode
Gcode refers to the file that a slicer generates in order to tell a 3D printer how to build a part. Gcode files may also be referred to as “build files”. The name gcode comes from the contents of the file itself - a series of commands that primarily start with the letter g.
The typical 3D printing software workflow is as follows: CAD file (typically STL file) goes into slicer, slicer generates gcode, gcode file is uploaded to machine
HIPS
High Impact Polystyrene (HIPS) is a low cost 3D printing filament commonly used as support for ABS prints. HIPS support structures can be easily removed from dual extrusion ABS prints using pliers. For internal geometries that are inaccessible, HIPS supports can be dissolved in a Limonene solution leaving only the ABS part behind.
Infill
FFF 3D printed parts are made with three main feature types: a solid outer shell, sparse infill, and solid top and bottom layers. The sparse infill (short for “interior fill”) makes up the majority of the interior of a part. Infill is usually printed anywhere from 10% to 50% density by volume. This means that if the infill density is 20%, the inside of the part will be 80% air. “Infill density” and “infill percentage” are used interchangeably.
Outlines
FFF 3D printed parts are made with three main feature types: a solid outer shell, sparse infill, and solid top and bottom layers. “Outlines”, “outline perimeters”, and “perimeters” are all used to refer to the extrusions that make up the solid outer shell. The thinner the outer shell, the faster the part will complete. The thicker the outer shell, the stronger the part will be. For most small to medium prototype parts, one or two perimeters is the norm. For large prototypes of substantial weight, parts that will be handled a lot, and functional parts, the number of outlines is increased in proportion to desired strength. For the vast majority of parts, it is more material and time efficient to increase strength by increasing the number of outlines rather than increasing the infill density.
Note that some 3D printing slicer programs specify a shell thickness as opposed to a number of outlines. The effect is the same in this case, thinner shell = faster print, thicker shell = stronger print.
PACF
Nylon Carbon Fiber (PACF) is the name for a family of popular 3D printing filaments known for their light weight, chemical resistance, heat resistance, and strength. PACF filaments consist of a base nylon polymer (most often PA6 or PA12) and chopped carbon fibers (usually 15-20% by weight). The chopped carbon fibers give the material its low density and improved stiffness while also contributing to its trademark matte finish. This matte finish also helps hide layer lines. Printing PACF successfully requires a 3D printer with a hardened steel nozzle, heated build plate, and enclosed build area - such as the GZERO Additive 43 Series.
PETG
Polyethylene terephthalate glycol (PETG, pronounced “pet gee”) is a co-polymer of PET that has advantageous properties for 3D printing. PET is used in many consumer products such as soda bottles. PETG prints have decent heat resistance, excellent chemical resistance, and good toughness. Recycled PETG (RPETG) filament is our go-to for prototyping and low to medium strength functional parts at GZERO Additive due to its versatility, printing speed, and low cost.
Perimeters
See outlines
PLA
Polylactic acid (PLA) is one of the most common 3D printing filaments for desktop and hobbyist printing. Made from bio sources, its high stiffness, low cost, and ease of printing make it the go-to choice for beginners and hobbyists. PLA has a relatively poor temperature resistance, so do not leave a PLA print in a parked car on a sunny day. For general purpose prototyping, GZERO Additive recommends recycled PETG.
Profile
A 3D printer profile or slicer profile is a collection of settings that tell the slicer how to generate files for a specific 3D printer with a specific material.
Retraction
In FFF 3D printing, filament is forced through a heated nozzle and deposited layer-by-layer to build a part. When a printer finishes a certain part feature or layer and has to traverse to the next feature or layer without printing, pressure buildup in the nozzle leads to molten filament oozing from the nozzle. To combat this, 3D printers will reverse the filament feed direction briefly after stopping, retracting filament backwards through the nozzle. Retraction is critical for making high quality prints. Retraction distance and retraction speed typically vary with material type and will be set in the slicer profile for your particular machine and material combination.
RPETG
Recycled PETG. Excellent and economical for making large scale prototypes. See PETG
Service Bureau
A 3D Printing Service Bureau is a company that offers 3D printing services for hire. Service bureaus cover everything from one-off prototypes to full production runs. GZERO Additive offers 3D printing services using our large, fast, industrial 3D printers. Click here for more information.
Slicer
A “slicer” or “slicing software” is a computer program that converts a 3D model of a part (typically an STL file) into gcode that is used by a 3D printer to build the part. Slicers allow the user to orient part(s), add supports as necessary, and preview the part before sending gcode to their 3D printer. Slicers use material and machine settings stored in profiles to account for different materials, strength requirements, detail requirements, and machine features when generating gcode files.
The typical 3D printing software workflow is as follows: CAD file (typically STL file) goes into slicer, slicer generates gcode, gcode file is uploaded to machine
Support
Most FFF/FDM parts with overhanging geometry require supports to print properly. In this context, support is material used to prevent the overhanging areas of each layer from falling down towards the printer’s build plate due to gravity. Common features that require supports include cantilevered overhangs, horizontal cutouts, horizontal holes, horizontal tabs, and long bridges. Supports can be printed from either the parent part material or from dedicated support material if using a dual extrusion printer. Printing supports from the same material as the part reduces print time at the cost of surface smoothness. Printing supports from a dedicated support material increases print time but results in a much better surface finish.
Z Offset
In FFF 3D printing, z offset refers to the distance between when the z-axis home switch trips and when the nozzle actually touches the build plate. An incorrect z offset will cause the nozzle to be either too far from or too close to the build plate when printing the first layer of the part. Both of these conditions can cause issues with bed adhesion. See also baby stepping