3D Printing Basics: Glossary

• ABS - Acrylonitrile butadiene styrene (ABS) is a filament that features excellent hardness and good heat resistance. The plastic is used in Legos™ and in a variety of industrial and commercial applications. On the other hand, it can be tricky to print, and the filament produces unpleasant fumes while printing.
• "Bed dropper" - A 3D printer that lowers the bed (Z-axis) as the print progresses. The print head moves along the X- and Y-axes.
• Bed leveling - The process of adjusting the print bed to be level—in relation to the print head—rather than in relation to the floor.
• "Bed slinger" - A 3D printer that moves the bed back and forth (Y-axis) during printing. The print head moves left and right (X-axis) and rises up (Z-axis) as it lays down layer.
• Bowden extruder - An extruder mounted to the frame of an FDM-tupe 3D printer. The bowden extruder pushes filament from the spool to the print head. A bowden tube guides the filament into the print head.
• Bowden tube - A PTFE (fluoropolymer—also known as Teflon®) tube which delivers filament from the bowden extruder into the print head.
• Bridges - See Supports.
• Direct drive extruder - An extruder mounted directly on the print head. It pushes filament directly into the print head for melting and printing.
• Extruder - In an FDM-type 3D printer, it squirts the melted filament onto the model.
• FDM - Fused Deposition Modeling—or FDM—is a type of additive manufacturing in which thermoplastic filament is precisely extruded in layers onto a print bed, forming objects. FDM printers are the most popular 3D printers today.
• Filament - Thermoplastics that are melted to form and extruded 3D models. There are many types of filament available, but PLA is probably the most popular, followed by PETG. All of the popular filaments are hygroscopic (readily absorb moisture) and must be dried and/or kept dry for successful 3D printing.
• G-code - G-code is a set of instructions that tell a specific 3D printer how to print a specific object, including position on the print bed, nozzle and print bed temperatures, infill percentage, support settings, etc. G-code is generally created by slicer (computer program).
• Hot end - The part of an FDM 3D printer that heats, melts and extrudes the material through a nozzle.
• Nylon - A high-strength, somewhat flexible filament for 3D printing. Nylon generally requires higher temperatures—250° C. and up—and may require that a basic printer be upgraded before printing in nylon. Printing a lot of objects at the higher temperatures, however, can shorten the life of the 3D printer. Nylon filament can be rather expensive and may be very difficult to print successfully, as it warps easily and is very hygroscopic (absorbs water from the air). On the other hand, nylon objects can be tough, long-lasting and can be dyed using ordinary fabric dyes.
• Overhangs - See Supports.
• PETG - Polyethylene Terephthalate Glycol (PETG) is a high-strength filament that can survive hot environments (like the trunk of a car) that can cause PLA to change shape. PETG tends to be more difficult to use successfully than PLA, and it is very resistant to most adhesives and most types of paint.
• PLA - Polylactic Acid (PLA) is a plant-based, biodegradable, recyclable filament made from materials such as sugar cane or corn starch. PLA is strong, non-toxic, cost-effective, and easy to use, making it a very popular filament for 3D printing. Printed objects can easily be painted or glued. PLA is generally the best filament choice for beginners.
• Slicer (computer program) - Software used to create instructions for printing an object. Typically, the user configures the slicer for a specific printer, then opens an STL file and selects the settings for the print. Slicing refers to instructions for printing each layer. The instructions are exported as a G-code file. Popular slicers include Cura, Prusa, and Orca.
• STEP file - A commonly used standard Computer-Aided Design (CAD) file format. STEP—or STP—files are often shared because they can be modified by someone with a CAD or CAM (Computer-Aided Manufacturing) program. Some CAD or CAM programs can be used to export STEP files as STL files, to use in 3D printing.
• STL file - STL stands for stereolithography, which uses a series of linked triangles to describe an object. STL files are opened in slicer software and exported as G-code, which is the instructions for the 3D printer.
• Supports  - Filament is very soft immediately after extruding. Overhangs—such as an outstretched arm of a model—and bridges—like the belly of a horse—can sag or collapse before the filament cools and hardens. Slicer programs make it easy to switch on supports, which are thin structures of filament that help to hold up overhangs and bridges while they cool.
• "Z hop" - Also called "Travel lift," this is a setting that governs the raising of the nozzle above the model while traveling from one part of the model to the other. This can help avoid collisions between the printer head and parts of the model, which can result in such things as detachment of support material (and failure of future parts of the model that are unsupported). Typical Z hop recommendations range from 0.2 to 0.4mm. Depending on your slicer, the default value may be zero.
• Z offset - A setting that adjusts the initial height of the print nozzle above the print bed of a 3D printer. A correct z offset is necessary for proper first-layer adhesion when printing, and to avoid damage to the bed from nozzle impacts. The ideal z offset varies between filament types.

William Edward "Bill" Masters (1950 - ). American engineer, inventor and entrepreneur. Bill Masters holds the first 3D printing patent (US 4665492). Masters is also the founder of Perception Kayaks and holds a number of patents related to kayak design and manufacturing.