glossary of 3d printing/AM & Related Technologies

2.5d printing

a "low relief" texture added to a 2d image.

3d printing

an additive process in the manufacture of physical objects from digital files called 3d models.

3d scanning

analysis and capture of volumetric data of an object or environment, for further translation into a virtual 3d model.

4d printing

the creation of a 3d printed object which can change shape over time.

5d printing

the creation of a 3d print on a 5-axis machine.

additive manufacturing (AM)

process of creating an object by selectively adding material in computer-controlled process, as opposed to milling and other methods that extract forms by cutting or milling material away from a larger block of material.

bed adhesion

the ability of prints to adhere to a printbed. It is a requirement for successful prints.

bioprinting

"Bioprinting is an additive manufacturing process where biomaterials such as cells and growth factors are combined to create tissue-like structures that imitate natural tissues" - from all3dp’s article.

brim

similar to a skirt, a brim can be added (via slicer software) to a 3d print to improve printbed adhesion and counter warping. It is deposited in the initial layer of a print along the outside edges of the model. Unlike a raft, it is not printed below the model.

CAD

Computer Aided Design software, which can be used to generate 3d models and their 2d counterparts.

calipers

useful for measuring/calibrating a print's dimensions, a MUST for reverse engineering.

CAM

Computer Aided Manufacturing, a software utility that produces toolpaths for machining (turning, milling) of parts.

constellation

a method for maximizing print time vs. volume. "This optional constellation element defines the relative pattern of the objects within the file. This allows multiple objects to be arranged within the file, specifying their location and orientation" from sculpteo.com.

extruder/hot end

chamber through which material is deposited, e.g., in an FDM machine, it is the part that melts and deposits plastic. Can also be used to deposit binders in powder-bed machines.

filament

typically rolled in a spool, a thermoplastic material used in FDM/FFF extrusion.

g-code

dataset of printing instructions (e.g., path, speed, temperature) sent from slicer software to a 3d printer.

generative design

the creation of a 3d model by inputting "design goals into generative design software, along with parameters such as materials, manufacturing methods, and cost constraints" (from Autodesk) While the algorithm is executed and iterated many (sometimes thousands of) times, the software learns which variations succeed in reaching the design goals.

industry 4.0

family of digital technologies used in manufacturing including cloud computing, robotics, artificial intelligence, connected physical assets aka Internet-of-Things (IoT), digital twins (physical assets connected to digital counterparts), data analytics, and additive manufacturing.

infill

percentage of material deposited inside an object during printing. This user setting can be used to reduce the material used, and resulting weight of a printed model.

ironing

a slicing software setting that uses an additional process on a 3d print’s top surface to create a smoother texture.

iterate

to create a new version of a previously existing model/design, often occurring in a series of changes (iterations) to approximate or evolve into the desired form.

layer height/thickness

resolution of the vertical (Z) axis of a print. Smaller layers result in smoother prints, at a trade-off of increasing the time it takes to print. In FDM machines, it is a user-defined parameter.

lightweighting

reduction in material weight (and often volume) of a part, while satisfying required design objectives (e.g., mechanical strength, material costs). Typically done with software tools such as finite element analysis.

manifold

model property with a "watertight" mesh surface; one with surface faces that have thickness; and contains a volume of space with continuous, non-intersecting edges/faces. A non-manifold edge in the outer surface of a model can only exist in a virtual model. If the edges or faces are non-manifold, a print will fail (ideally, slicer software will identify this as a problem).

mass customization

ability to produce one-off products in a manufacturing process of considerable (or mass) quantity.

model

digital file containing topological data of a virtual 3d object. Models are an inherent necessity of 3d prints. They can be sourced from CAD or sculpting software, or 3d scans.

overextrusion

excessive material extrusion from the hot-end of an FDM machine. Often results in stringing or bridging where filament should not be extruded.

parametric model

a model that consists of user-defined features, or parameters. Modifying the model can be done with changes in parameters (e.g. length), rather than direct movement of edges, faces, or vertices.

photoactive polymer, photopolymer

as used in AM/3d printing, a plastic resin that hardens when exposes to light.

photopolymerization

AM process in which the hardening of a resin using a controlled light source to "draw" patterns of model slices.

post-process

after removal of a 3d print from a printbed/resin vat, prints often require removal of support structures, or powder residue. Some AM technologies incorporate a process to strengthen the prints, such as exposing to infiltrants, or UV curing resins in SLA.

powderbed

chamber where (depending on the technology) metal or plastic powders are fused in SLS, DMLS, and MJF AM processes.

printbed

surface upon which an FDM or powder 3d printer begins prints. In FDM machines, printbeds may be heated, facilitating part adhesion, minimizing warping, and allowing easier print removal.

print volume

volume of a part printed, or maximum printing volume of a 3d printer.

prototype

product built for functional testing, if necessary, fit, and/or visual example before committing to commercially manufacture of said product.

raft

typically used to increase bed adhesion and reduce print warping. A raft is an optional user setting in FDM machines in which a layer of filament is deposited between a 3d printed model and the printbed.

rapid prototyping

enabled by additive manufacturing, it is sometimes used in place of "3d printing"

render

a 2d image from a 3d model or scene. User controls include lighting, perspective, material appearance. High quality renders can result in photorealistic images.

retraction

reversal of filament flow in the extruder before it makes non-depositing travel moves. This prevents "stringing" or extrusion in areas outside of a model during the print process.

shell

a user-defined setting, "shell" count refers to the number of outlines printed in a single layer. Shells are related to wall thickness.

sinter

manufacturing process that uses heat to bond powder particles (e.g. nylon, metals).

skirt

slicer setting that puts a first-layer outline around the bottom perimeter(s) of a 3d print. It can be used to provide visual feedback of extrusion quality, adhesion, and bed leveling where the model is set to print.

slicing software, aka "slicer"

the majority of 3d printers operate by extruding material in a series of cross-sectional images of a file ("slices"). Slicing software converts 3d model data into instructions for 3d printer, called g-code, which includes layer paths and support structure placement. The selection of slicing software is an essential decision for kit model printers, less so for commercial models as they often run with manufacturer-provided slicers.

subtractive manufacturing

method of manufacturing in which a product is extracted by cutting or milling material away from a larger block of material.

supports

auxiliary structures that are printed along with a 3d model to support protruding or cantilevered sections, and to provide a foundation for layer deposition that begins above the printbed, e.g. overhangs.

thermoplastic

the raw material used in plastic AM processes.

topology optimization

means of generating a design with optimized strength to weight ratio. Variations can be compared for cost of materials, strength under simulated stresses, and so on.

underextrusion

insufficient filament extrusion for expected outcome. Parts can be printed with gaps in areas such as those between infill and walls.

vase mode

slicer setting that enables 3d printing models with walls that consist of single layers. Alternatively, "spiralize" is used to describe this setting in which the model is printed in one continuous run.

voronoi

a mathematically derived design from the drawing of boundaries around (typically, random) dots. Designs of this nature take on an organic appearance, as the boundaries resemble the outlines of cells. A voronoi around uniformly placed dots may take on a honeycomb appearance.

voxel

volumetric pixel, a basic unit of resolution for light-based AM, medical imaging, and gaming technologies.

wall

the perimeter of a 3d print, the thickness of which can be adjusted as a user-defined setting, "shell" count. It is important to note that if the thickness of a shell is adjustable, rather than number of shells, it ideally should be set to a multiple of the print nozzle diameter.

warping

bottom print layers fail to retain adhesion at outer edges during a print. This is more likely when the bottom layers cool too quickly, causing contraction.