3d Printing Terminology
3D Printing terminology can often feel overwhelming and complex, to simplify here’s a list of some terms to know!
General 3D Printing Terms
Additive Manufacturing: The method of creating a part by building material layer by layer from a CAD model (more commonly known as 3D Printing)
Fused Deposition Modeling (FDM): The most common type of 3D Printing where objects are produced by laying plastics layer by layer on a bed utilizing a heated nozzle.
Stereolithography (SLA): A slightly less common type of 3D Printing which uses UV screens to cure plastic resin onto a bed. While more precise, materials are generally weaker and prints require a lot more post processing (hence the lack in FTC).
Selective Laser Sintering (SLS): One of the least common types of 3D printing, you likely won’t come across one of these machines in your FIRST career due to their cost. SLS machines utilize concentrated lasers to bind together patterns in material powder, eventually resulting in a complete part.
Filament: Plastics made of polymer resins that become soft above a certain temperature and harden when they cool. Common filaments include PLA, PET-G, ABS, Nylon, and Acrylic. These generally come in continuous rolls that you feed into your printer.
Direct Drive: A type of FDM extruder where the extruder motor is placed on the carriage together with the hotend assembly, shortening the distance that filament needs to travel significantly.
Bowden: A type of FDM extruder where the extruder is placed at a different spot on the printer separate from the carriage and runs filament through a long PTFE tube to reach the hotend.
3D Printer Parts
Carriage: The moving head of a printer that contains the hotend assembly.
Bed: The heated (or sometimes nonheated) surface that filament is laid upon.
Hotend: The part that melts filament it typically consists of a heat sink, heater, thermistor, and metal nozzle.
Gantry: The frame structure that supports the printing head/hotend as it moves.
Stepper Motor: The small motors that move each axis of the printer with precision.
Extruder: The stepper motor that moves filament into and out of the hotend, whether from up close or far away.
Drive Gear: The gear located on the extruder stepper that grips and moves the filament. Extruders can be either single drive gear or dual drive gear, with dual having more grip.
Bowden Tube: The slippery tube that is located on your printer that allows filament to pass through it. They are made of PTFE, a low friction compound that can degrade at higher temperatures.
Axes: A 3D printer has 3 axes, with the X and Y typically being interchangeable and the Z axis being up and down. There will normally be one or more steppers controlling each of these axes.
Hotend Cooling Fan: All hotends have a heatsink around them to dissipate heat and prevent it from interfering with other printer functions (“heat creep” is a common issue with poor hotend cooling, in which filament crumples upon itself instead of being pushed through the extruder). The hotend cooling fan is directed at the hotend heat sink in order to prevent issues and help further dissapate heat.
Part Cooling Fan: Most printers also have a fan directed below the nozzle to cool parts as they’re printed. Some filaments don’t print very cleanly without cooling, drooping over themselves, so this is a very important part of the printer for print quality. PLA is easily one of the most volatile materials when it comes to cooling.
Design Terms
Tolerances: Formally described as “the permissible limit of variation”, saying that this is how much we expect parts to vary in size due to the inconsistency of manufacturing.
Pressfit/Interference Fit: The tolerance at which pieces will be able to pressed together and stay together, whether that be a bearing in a hole or two 3D Printed parts snapping together.
Throughhole/Thruhole/Slipfit: The tolerance at which a piece can freely pass through another, for example being able to drop an M4 screw into a hole with little to no resistance.