3D Printing Glossary

Term

Definition

1st Layer This is the first layer of plastic which is laid down on the build plate at the start of a print. It is the most important layer of a print, as it used for adhering the part to the bed.
3D Model A mathematical representation of the three-dimensional surface of an object (in the case of Robox®) constructed using triangles, also known as a mesh. There are many file formats for this, with Robox® accepting .stl and .obj.
3DP Abbreviation of 3D Printing
ABS Acrylonitrile Butadiene Styrene, a thermoplastic used as a 3D printer material. It produces tough, impact-resistant parts which make excellent functional prototypes. It can be tapped, sanded, painted and vapour polished allowing for high quality finishing.
Accuracy Generally used to describe the theoretical accuracy of the motion system. This is calculated from the step accuracy of the stepper motor used for control and the pitch of the leadscrew / belt. See section X.X for accuracy specifications.
Acetone A colourless, flammable liquid also known as propanone – a solvent which will dissolve ABS and can be used as a cement for gluing parts together. It can also be used for ‘vapour smoothing’ see section X.X.
Additive Manufacturing (AM) The process of constructing an object by selectively adding material, rather than starting with a block of material and cutting away what you don’t need – see subtractive manufacturing
Ambient Temperature This refers to the air temperature inside the build chamber during the print. Maintaining this at a stable temperature can help to reduce warping of parts as they are produced by encouraging even cooling.
.AMF AMF serves is an alternative to the STL file format based on XML which supports units, colour, textures, curved triangles, lattice structures, and functionally-graded materials—features that the STL format does not support.
AutoMaker The included software package which is used for controlling all elements of your Robox®, including printing, layout, calibration and maintenance.
Axis (Axes) Describes a single direction of movement in a 3-dimensional coordinate system. X axis runs left to right, Y axis is front to back and the Z axis represents what would typically be considered “vertical”.
Backlash Sometimes called lash or play, it describes the ‘slack’ in a mechanical system. In the case of the pulleys and belts, it could be caused by the tooth profile of the belt not matching the pulley, or by the pulley being loose on the shaft which drives it.
Bed The surface at the base of the 3D printer on which parts are actually made. Robox® has a removable ThermoSurface build plate to allow for easy part removal.
Belt The toothed gear belts which are used in conjunction with a drive pulley to transfer movement from the motors to other parts of a machine. Usually fibre-reinforced to prevent stretching.
Bowden Tube This is the tube which delivers the filament to the print head. It is manufactured from PFA/PTFE to reduce the friction on the internal surfaces while maintaining flexibility.
Bridge This refers to a feature in the printed object where an unsupported flat surface is produced by essentially printing ‘in thin air’. It is achieved by moving the printhead more quickly, and bonding the extrudate to either side of the gap so that it is stretched and can cool before it begins to ‘sag’.
Brim ‘Brim’ is a term applied to 3D printing which describes a large flat area which is printed around the part to help with bed adhesion and warping – like the brim of a hat. See section X.X.
Build Chamber This is the enclosed area of Robox® where parts are produced, and is designed to maintain the ambient temperature and prevent draughts from affecting the quality of your print.
Build Envelope This refers to the maximum dimensions of an object which can be produced with Robox® – 210x150x100mm (LxWxH)
Build Plate See bed.
CAD Computer Aided Design – used for designing objects.
Calibration The mostly automated process of adjusting software parameters in AutoMaker™ to take into account any differences in the manufacturing/assembly process of Robox®. See section X.X.
Carriage This refers to a moving assembly which is constrained to one axis – Robox® has 3 – the Z carriage which holds the X motor and rails, the X carriage that holds the print head, and the bed could be described as the Y carriage.
Cartesian Axis A coordinate system which describes the location of an object in three dimensions – X, Y and Z.
Caustic Soda See Sodium Hydroxide.
CNC Abbreviation of Computer Numerical Control – controlling motion using a computer which sends instructions as GCode.
Console A means of entering CNC commands manually by sending typed text instructions.
Delamination A defect in a 3D printed object where layers have not correctly fused together, resulting in a gap between layers. It can be caused by underextrusion, incorrect material process parameters or by excessive warping/shrinkage.
Desiccant A chemical substance which absorbs moisture from the surrounding environment.
Drive Screw Also known as a lead screw, this is a thread which is used to convert rotational motion (from a stepper motor) into linear motion. In Robox®, drive screws are used to move the gantry up and down.
Dual Extrusion A type of 3D printing where two different materials can be extruded on the same layer using two nozzles.
EEPROM Abbreviation of Electrically Erasable Programmable Read Only Memory – the type of memory which is used to store parameters in the printhead and SmartReel™.
Endstop Also known as a limit switch, this refers to a microswitch which is used to define the limits of a motion axes. Also see Homing.
Extrudate This refers to material which has been extruded from one of the nozzles on the printhead.
Extrude The act of placing the build material on the build platform, normally by heating thermoplastic to a liquid state and pushing it through one of the nozzles on the printhead.
Extruder This device is used for pushing the filament to the head along the Bowden tube. It uses two contra-rotating feedwheels to pinch the filament and feed it in a very controlled manner using a stepper motor.
Faceted This refers to the appearance of a low-resolution 3D model, where individual polygons are visible in the printed object. The resolution of a 3D model is controlled by 3 parameters – chord length, step angle and step size. Reducing the size of these three values will result in a higher resolution model (smoother surface).
Feed Rate This describes the speed at which motion axes move, usually in mm/s and can refer to the X, Y, Z and extruder ‘axes’.
Feedstock See filament.
FFF Fused Filament Fabrication. Where a filament of one material (plastic, wax, metal, etc.) is deposited on top of or alongside the same (or similar) material making a joint (by heat or adhesion).
Filament The ‘feedstock’ for a FFF 3D printer – a thermoplastic which has been extruded into a 1.75mm diameter ‘wire’ which is fed to the print head and melted before being extruded onto the build plate.
Fill This describes all extruded material on the inside of a printed object. It’s density can be varied between fully hollow and fully solid.
Fill Density This describes the density of the fill – 0% for a hollow object, 100% for a fully solid object.
Firmware This is the computer program which runs on the hardware itself and is stored in flash memory on the mainboard.
Flash Storage This refers to the storage available on Robox® to store GCode print instructions during printing. It also maintains a history of previous prints, allowing them to be reprinted without reslicing. It is cyclic storage (once full, begins to overwrite from the beginning) which is not accessible on any device except Robox®. A microSD card is used as the storage medium.
Flow Rate This describes the rate of extrusion from the nozzle – normally measured in mm³/s.
Footprint This is the amount of flat area Robox® occupies when stood on a surface – 370x340mm.
Gantry This describes the assembly which includes the Z carriages, X rails and X carriage. Its level is adjustable using two independent Z drive screws.
GCode The industry standard language for CNC control commands – it has two distinct subsets – G and M codes, where G codes are motion commands, and M codes are logic commands, such as heater control.
HeadLock™ Refers to the printhead replacement system in Robox® – it allows you to change the printhead quickly and easily.
HIPS High Impact Polystyrene – a simple thermoplastic which is frequently used as dissolvable support material as it bonds well to ABS and can be dissolved in Limonene, leaving the ABS part intact – see section X.X
Homing As there is no direct feedback from the stepper motor in terms of position, homing is how Robox® determines the location of all axes before starting a print. Each axis moves until it reaches its endstop, which is then defined as the origin. Because the software knows the length of each axis, software limits can be used at the other end of travel.
Hot End This commonly refers to the heated nozzle section of the extrusion system and includes the heater block and nozzles inside the printhead.
Hygroscopic This describes the tendency for some thermoplastics to absorb moisture from the air – see section X.X.
Infill See fill.
Kapton® Tape Kapton® is a trade name of polyimide, frequently used for high temperature adhesive tapes and films. Many other printers use Kapton® film as a bed surface, however in Robox®, ThermoSurface removes the need for any coating on the bed.
Layer Height This describes the height in mm of each individual layer of the 3D printed object. The thinner each layer is, the smoother the appearance of the outside surface will be, reducing the ‘stair stepping’ effect. Thinner layers = more layers = longer print.
Levelling This refers to the process of ensuring the nozzle is always the same distance from the print bed to ensure accurate extrusion, good base surface finish and adhesion. Robox® performs the operation automatically in both dimensions, by adjusting the level of the gantry and continually adjusting its height as the bed moves back and forth.
Linear Bearing This is a mechanical component which is used to constrain motion to 1 DoF (Degree of Freedom) – i.e. it can only move along a rail and cannot rotate. Linear bearings are used in the bed, Z carriage and X carriage to ensure the accurate position of the printhead.
Macro This refers to a sequence of GCode instructions which are executed sequentially to perform a particular function.
Manifold This is a term which is used to describe whether a surface model contains any gaps in its surface – i.e. whether it is ‘watertight’. Non-manifold surface models may produce errors in slicing, as the software is unable to define that edge.
MEK Methyl ethyl ketone, also known as butanone is commonly used as an industrial solvent and polymer cement. It can be used for joining together printed parts and ‘vapour smoothing’ but must be used with care, as it can irritate skin and eyes. See section X.X.
Mesh See 3D Model.
Micro-Manufacturing A term used by us to describe the manufacture of objects on your desktop – i.e. a personal factory. Also used in industry to describe the manufacture of very small objects.
Microstepping A method of increasing the number of steps per rotation of a stepper motor by varying the supply to the coils, allowing for increased resolution and smoother operation.
Model See 3D Model
Nozzle This is the part of the printhead through which material is extruded. Robox® has two nozzles of different diameters – 0.3mm and 0.8mm – with the smaller being used for fine details and the exterior surface of the part, and the latter being used for infilling the part at high speed by extruding a large amount of material at once.
Nozzle Height On Robox® this is used to describe the difference between the mechanically determined surface position (the bed) and the actual position.
Nozzle Opening On Robox® this describes the point at which plastic begins to flow from the nozzle, based on the position of the needle valve.
Nylon Nylon or polyamide (PA) is an engineering grade thermoplastic used in a variety of applications. It is extremely tough and durable, making very strong functional parts.
.OBJ Abbreviation of OBJect – a file format used to define a 3D model similar to .STL, but an .OBJ file can contain multiple models and also colour/texture data when used in conjunction with a .MTL (material) file.
Ooze This is a phenomenon experienced on many other FFF printers, where molten plastic continues to flow from the nozzle when the extruder has stopped. It is conventionally compensated for using a ‘retract’, where the filament is pulled back to ‘suck’ molten material away from the tip of the nozzle. Robox® uses a needle valve system to stop the extrusion as required at the tip of the nozzle, resulting in minimal ooze.
Overhang Describes an unsupported area of a 3D printed model. When automatic support generation is enabled, an angle threshold is used to define where support is generated – see section X.X.
Parametric (Adjustable in all dimensions. A parametric model is one that can be resized and or distorted to suit the user’s needs. In CAD software, you can resize individual features (e.g. holes, ribs etc.), as opposed to a mesh (surface model), which is more difficult to adjust.
Perimeter In FFF used to describe an extrusion path that runs around the perimeter of the object. e.g. number of perimeters sets the wall thickness of the object.
PLA Polylactic Acid. A biodegradable thermoplastic polymer manufactured from corn starch which is frequently used as a 3D printer material.
PP Polypropylene – a ‘waxy’ flexible thermoplastic which can be used for 3D printing, however it is particularly susceptible to shrinkage and warping issues due to its large thermal expansion coefficient.
Print Head This is the ‘end-effector’ of Robox® which can perform a number of different functions depending on the model. The standard model is a single material, dual nozzle FFF head for producing 3D prints from a range of thermoplastic filaments.
PTFE Polytetrafluoroethylene (Teflon®) – A high temperature engineering thermoplastic with an extremely low coefficient of friction – used to line the filament path to the head.
Pulley More specifically – a timing pulley – used for translating rotational motion into precise linear motion. The pitch of the belt and the number of teeth on the pulley defines the resolution.
Purge When switching between two dissimilar materials, it is important to remove the old material from the head completely to prevent blockages. Purge is a routine that chooses an intermittent melt point and forces through material to effectively switch between materials.
PVA/PVOH Polyvinyl Alcohol – A water-soluble filament used as 3D printing material, often for dissolvable support. See section X.X.
QuickFill™ This refers to the twin nozzle system used by Robox® for reducing overall print times. By using a fine and fill nozzle, the exterior of the part can be produced slowly and carefully by the smaller nozzle, and then the inside can be filled quickly with the larger nozzle.
Raft A technique used to prevent warping. Parts are built on top of a ‘raft’ of disposable material instead of directly on the build surface. The raft is larger than the part and so has more adhesion. Similar to brim in functionality.
Rail A hardened and ground steel round bar used for constraining linear motion to one DoF.
.ROBOX A Robox® file – contains an AutoMaker™ project which includes your layout of objects on the print bed and all associated print settings and slicing parameters.
.ROBOXFILAMENT A Robox® filament definition file – contains material properties for a particular filament e.g. melt temperature.
.ROBOXHEAD A Robox® head definition file – describes a particular head type and associated default parameters.
.ROBOXPROFILE A Robox® print profile – contains slicing parameters
Repository (Typically) an online store of 3D models for printing.
RepRap A RepRap machine is a rapid prototyping machine that can manufacture a significant proportion of its own parts.
Resolution Typically used to describe the layer height and positional accuracy of a 3D printer. Please refer to specifications in Section X.X.
Retraction Often used in other printers to control ooze – describes the ‘pulling back’ of filament from the print head. Also see Ooze.
Robox® Account Your Robox® account must be registered when using AutoMaker™ for the first time to allow us to offer effective support and send software updates.
Routine See Macro.
RP Abbreviation for Rapid prototyping. Creating an object in a matter of hours using additive manufacturing.
Shell Used to describe the outside surfaces of a 3D model.
Silica Gel A desiccant which can be used for reducing the water content of filament. It can be reactivated by slow oven drying or microwaving – times depend on the quantity.
Slice The process of converting a 3D model into individual layers or ‘slices’ for printing. Toolpaths are generated to describe the motion of the printhead and extruder in GCode.
Slicer The part of the software which is responsible for producing GCode instructions for printing from a 3D model.
SmartReel™ A Robox® filament reel which includes an EEPROM for storing material parameters – allowing for instant machine set up when it is installed in the dock.
Sodium Hydroxide A highly caustic alkali salt which can be used in solution to dissolve some types of dissolvable support material – see Section X.X.
Solid Model A type of CAD model which is represented by geometrical features (circles, rectangles etc.), rather than a list of vertices which form a polygonal mesh (surface model). Example of solid model file formats include .STEP and .IGES and they can be exported from many CAD packages.
Spool Another term for the filament reel – see SmartReel.
Stair Stepping A phenomenon common to all FFF printers to varying degrees, it describes the appearance of individual layers, particularly visible on surfaces close to horizontal at larger layer heights. To minimise this effect, you must reduce the layer height.
Step Angle The angle of a discrete increment of rotation of a stepper motor.
Stepper motor DC Motors which operate only in discrete increments of rotation (steps). Robox® uses motors with a step angle of 1.8°, meaning there are 200 discrete steps per rotation.
.STL Short for Stereo Lithographic, the most common file format of 3D models for 3D printing. It only contains geometry data in the form of a polygonal mesh, and is slowly being replaced by more advanced standardised formats such as .AMF.
Stringing A print defect characterised by thin ‘strings’ of polymer between separate extrusion paths. It is caused by ooze – as the head travels to another location, it drags a string of molten plastic from the head, affecting the surface finish of the part.
Subtractive Manufacturing This is the traditional means by which an object is manufactured, usually by machining. Starting with a ‘blank’ of raw material, you cut away the areas you don’t require, rather than just building the areas you do – see Additive Manufacturing.
Support Material Support material describes printed material which is not part of the desired object, but is produced for supporting areas which are not sufficiently supported. Because FFF relies on laying down material on top of a previous layer, it cannot print effectively in thin air – except bridges over a short distance. It can be produced from the same material as the model (Breakaway Support) or a different material which can be removed by chemical means (Dissolvable Support) See Section X.X.
Surface Finish This describes the quality of the outside surfaces of the part, which can be affected by a wide range of factors.
Surface Model Describes a type of 3D model which only contains surface data in the form of a polygonal mesh. They do not have to be ‘manifold’ and can therefore cause issues with slicing if not prepared correctly.
Thermoplastic This is a type of polymer which softens on heating, allowing it to be formed into a different shape. This differs from a thermoset plastic, which is formed by a chemical reaction and does not soften on heating, but will degrade.
ThermoSurface This is a high performance engineered thermoplastic. The bed surface of Robox® is known as ThermoSurface it bonds particularly well to molten ABS and PLA – important for bonding the first layer to the bed.
Toolpath This describes the motion that the printhead takes to produce a layer written in GCode motion coordinates.
Transition Point This term is used to describe the point at which the solid filament becomes molten in the head assembly.
Underextrusion A print defect characterised by a lack of material being extruded, leading to surface finish errors and bad layer bonding. It is usually caused when the extruder cannot force filament into the ‘hot-end’ fast enough, due to blockage, softened/wet filament, or incorrect material parameters.
Vapour Smoothing This is a process used to smooth out the surface of a 3D printed model by vaporising a solvent and then allowing to condense on the surface of the model – causing partial melting and a smoothing effect. See Section X.X.
Viscosity Viscosity is a property of fluids determining it’s resistance to flow. The higher the viscosity, the more difficult a material will be to extruded or dispensed (more energy/pressure will be needed).
Warp A print defect caused by uneven cooling of the part, particularly severe in certain materials such as PP, HDPE and ABS. The enclosed build chamber of Robox® is designed to help reduce these effects, by causing the part to cool down uniformly at the end of the print and reducing draughts. See Section X.X.
‘Watertight’ See Manifold.
WPC Wood Polymer Composite – a composite material produced from wood ‘flour’ and a thermoplastic. Can be used for printing ‘wood like’ objects.
X Axis This is the axis which controls the motion of the head left and right along the X rails, driven by a belt and pulley system.
X Carriage The X carriage contains the HeadLock™ system for attaching different print heads and moves left to right along the X rails.
Y Axis This is the axis which controls the motion of the bed forwards and backwards along the Y rail, driven by a belt and pulley system.
Z Axis This is the axis which controls the motion of the gantry up and down along the Z rail, driven by leadscrew.
Z Carriage These are the plastic housings which hold the X rails perpendicular to the Z axis and form the two sides of the gantry.