Idiot's Guides: 3D Printing (2015)

APPENDIX A

Glossary

ABS Acronym for acrylonitrile butadiene styrene, a type of thermoplastic commonly used for 3D printer filament. It is strong but prone to warping and cracking during printing.

ABS juice Also called ABS glue, a solution of ABS plastic dissolved in acetone. It makes a very sticky substance that can be used as a surface treatment on the print bed to improve adhesion.

acetone A common household and industrial solvent. Acetone breaks down styrene, which allows it to dissolve ABS. It can be used for smoothing ABS prints and for making ABS juice.

additive manufacturing The process used by all 3D printers, in which a part is created by slowly adding layer after layer of material.

Arduino An open-source platform for developing and prototyping electronics. Arduino models are generally small circuit boards without inputs and outputs for controlling various electronics. The Arduino Mega is used by the RAMPS control board for 3D printing.

Basic Input/Output System (BIOS) The firmware interface used on most computers. It’s the first thing to load as soon as your computer starts up and controls how the operating system (Windows, for example) is booted.

borosilicate Also known as Pyrex (one of its trade names), a type of glass that is formulated to reduce thermal expansion. Because it’s much less prone to thermal expansion than normal glass, it’s at a much lower risk of thermal shock. Thermal shock can crack traditional glass if it’s quickly heated or cooled unevenly, a problem that borosilicate doesn’t experience.

Bowden A general category of cold end where the filament is fed from a stationary location through a feed tube and into the hot end.

calipers A common measurement tool used in a wide range of fields and industries. They come in both analog and digital varieties and are used to measure lengths, distances, and depths. Calipers are capable of very high precision and commonly come in 6- to 12-inch sizes (though larger and smaller ones exist).

Cartesian An adjective used to describe things related to René Descartes, who was a French mathematician and philosopher. His many contributions to mathematics were the reason for the Cartesian coordinate system being named for him (though he wasn’t solely responsible for its development). In the context of 3D printing, it is a way of defining points in 3D space by their X, Y, and Z coordinates.

chamfer A simple beveled edge that connects two surfaces. If the surfaces meet at 90 degrees, a standard chamfer will cut across at 45 degrees for symmetry. However, a chamfer does not have to be symmetrical and can cut across at other angles as well.

cold end The part of the extruder assembly that has a stepper motor and drive system to feed the filament into the hot end.

computer-aided design (CAD) The process of designing parts using computer software (either in 2D or 3D). It also refers to the software used to accomplish that.

computer-aided manufacturing (CAM) A term used to describe manufacturing processes that are controlled by a computer (generally CNC mills). It also refers to the software used by the computers for controlling the machinery.

computer numerical control (CNC) A way of controlling machine tools using a computer, often used for computer-controlled milling machines.

control board The brain of the 3D printer, the control board is responsible for handling and processing all of the inputs and outputs on the printer.

coupler A mechanical fastener used to connect the lead screws on the drive system to the shaft of the stepper motor.

Delrin A trade name for a type of low-friction plastic.

digital light processing (DLP) One of many 3D printing processes, DLP uses projected light to cure photopolymer resin in layers.

direct drive A type of extruder that doesn’t use a gear reduction system. Because of the relatively low torque, direct drive cold ends are generally only suitable for 1.75mm filament.

direct feed A category of cold end where the drive system is located directly above the hot end, so filament is fed directly from the cold end into the hot end.

drafting The process of creating technical drawings of parts and assemblies. A person who does this is a drafter (or draftsman or draughtsman). Traditionally, this was done with a pencil and paper, but it is now done almost exclusively with CAD software.

enclosure A case that surrounds the 3D printer to keep hot air in and cold drafts out. Enclosures can significantly reduce warping and cracking on printed parts.

end stop A switch at the end of each of the 3D printer’s axes that tells the control board when each axis is at its limit.

extrusion The process used by FFF 3D printers to melt plastic and deposit it by squeezing the molten plastic through a nozzle.

filament The material used by FFF 3D printers, which comes in the form of a long strand of plastic and is generally wound on a spool.

firmware The program that runs on the control board for controlling the 3D printer.

flatness One of many terms used in engineering to specify geometric tolerances. In the case of 3D printing, it describes how flat a surface is.

flexible filament An umbrella term for any filament material that is flexible, rubbery, and squishy. This can be used as an alternative to the hard and rigid plastic that is more commonly used for 3D printing. The exact composition differs depending on the manufacturer, but the resulting material is fairly similar with all of them.

fused filament fabrication (FFF) Also called fused deposition modeling (FDM), the 3D printing process used by almost all consumer 3D printers.

G-code A programming language that 3D printers and other computer-controlled machine tools can use for instructions. The G-code is what is used to give most 3D printers the commands they follow to produce parts.

green sand A specially formulated material used for sand casting. Sand casting is used to produce metal parts by pouring molten metal into a mold made of sand. The mold is normally produced by forming it around a positive master part; however, 3D printing the mold removes the need to first create a master part.

Hall effect Discovered by Edwin Hall in 1879, refers to the tendency for voltage in a circuit to change when exposed to magnetism. It can be harnessed to create proximity sensors and is sometimes used for end stops and probes.

heated bed A type of 3D printing build platform that is electrically heated in order to aid adhesion and reduce warping.

heated build chamber Similar to an enclosure, except it is actively heated. Heated build chambers can often eliminate warping and cracking entirely.

heating element A simple electrical resistance-based heating device usually used to heat up the hot end.

HIPS Acronym for high-impact polystyrene, a type of plastic that can be used as support material for 3D printing. It dissolves in limonene, so it can be removed chemically to avoid damage to the printed part.

host software The software that runs on your computer and connects your computer to the 3D printer. It can be used to manually control the printer, as well as to send files to be printed.

hot end The part of the extruder assembly that heats and melts the filament that is fed by the extruder assembly. As filament is pushed into the hot end, a heating element heats the hot end. The temperature is hot enough to almost instantly melt the plastic into a very viscous fluid, which is then squeezed out of the nozzle and deposited on the print bed.

hypotenuse The longest side of a right-angled triangle. It is always the side whose endpoint doesn’t touch the right angle.

intellectual property Any idea that is legally protected. Providing legal protection for intangible things like ideas is a complicated matter, and the laws vary from country to country. But in the United States, intellectual property like inventions, music, copywriting, patents, and so on are legally protected property.

layer height How thick each individual layer is. The height is inversely proportional to both quality and print time, so the thinner each layer is, the longer it will take to print and the better the quality will be.

LCD controller A device that connects to the control board and lets you control the 3D printer without having a computer attached.

lead screw A precision-machined component for translating rotary motion into linear motion.

mechanical advantage The amplification of force with the use of a tool or mechanical system. This is usually achieved by trading movement distance for force. A lever is the most basic example of this, because if one side of the fulcrum (pivot point) is twice as long as the other, it will double the force exerted (though it will also double the distance it needs to be pushed). This same basic concept is applied in a vast array of machines using things like gears, pulleys, screws, and so on.

MultiJet Printing (MJP) A 3D printing process that uses multiple nozzles to spray binder onto powder.

nozzle The small opening at the end of the hot end that determines how thick the extruded filament is.

nylon A type of plastic that is noteworthy for its very low coefficient of friction. It can be found in filament form for 3D printing.

open source A philosophy and usage rights system that allows information to be shared freely.

parametric A 3D modeling system used by CAD software that defines the model by a series of parameters which can be modified.

PET Acronym for polyethylene terephthalate, a type of plastic that can be used as a 3D printing surface in film form or as a 3D printing material in filament form.

photopolymer resin A type of liquid resin that solidifies into plastic when exposed to light (usually in the ultraviolet spectrum). Manufacturers can produce the resin in many varieties, with different mechanical and chemical properties.

pitch The distance from one thread to the next. This is what determines how far the screw and nut will move (relative to each) with one full rotation. For example, an M8 screw has a standard pitch of 1.25mm. So if you have a lead screw with an M8 thread, every full rotation of the lead screw will move the nut 1.25mm.

polycarbonate A very strong plastic that can be 3D printed. This is the type of plastic that bulletproof windows are made from.

polyimide film Often referred to by its trade name Kapton, a film that can be used as a 3D printing surface to improve adhesion. It can also be used as a tape in very high-temperature applications, such as on the hot end.

powder bed printing Any type of 3D printing process that applies a liquid binder to powder.

print fan A small fan that cools the extruded plastic after it has been deposited.

rapid prototyping A term that is often used synonymously with 3D printing.

RepRap This can refer to the RepRap project, which develops open-source 3D printers, as well as the 3D printers themselves.

reverse engineering The process of determining the function and/or design of a man-made object or system. This can be anything from reverse engineering software to complicated mechanical systems.

scale The size of a part in relation to its physical real-world counterpart. It is often used to represent something large (like a building) at a manageable size.

selective laser sintering (SLS) A 3D printing process that uses a laser to essentially melt a powder into a solid piece. This process can be used for 3D printing metal parts.

shield In the context of Arduinos, a circuit board designed to be attached to the Arduino board. Shields are generally used to expand the capabilities of Arduinos by adding either more connections or sensors. They are usually designed for a specific application (like GPS tracking or to interface with another device), although plenty of general-use shields exist.

slicing software The 3D printing software that takes a 3D model and converts it into a series of instructions for the 3D printer.

smooth rod A cylindrical metal rod used in 3D printers for linear motion.

square-cube law Describes the mathematical relationship between area and volume. Its relevance to 3D printing is the way that volume (and therefore print time) increases exponentially with size. For example, a cube 10mm to a side has a volume of 1,000mm3. Doubling the dimensions of the cube to 20mm to a side results in a volume of 8,000mm3. Because the larger cube is 8 times the volume, it will take 8 times longer to print than the smaller cube.

stepper motor A type of electric motor commonly used for 3D printers because its rotation can be very precisely controlled.

stereolithography The very first 3D printing process, this uses a focused UV laser to cure photopolymer resin.

STL A file format used to store 3D models. This file format is used by almost all 3D printing software, as well as CAM software.

surface finish The quality (generally smoothness) of the surface of a printed part.

tangent Refers to a line that touches a curve at a single point and continues straight on from that point. The easiest way to visualize this is to picture a circle. A tangent line touching the far-right side of the circle will continue on vertically (up, down, or both), touching just a single point of the circle. The actual mathematics of defining a tangent line are fairly complicated, but luckily CAD software handles all of that—you only need to be concerned with the practical effect.

thermistor An electronic component that changes resistance based on heat. It’s usually used to monitor the temperature of the hot end and heated bed.

thermocouple A type of temperature-measuring device used in a wide range of industries. It’s inexpensive and doesn’t require a power source, which makes it ideal for some applications. However, thermocouples aren’t very accurate, which generally makes them unsuitable for use in 3D printer hot ends.

threaded rod A type of fastener that is basically a long bolt without a head at the end. A threaded rod is often used in place of lead screws on 3D printers.

units The unit of measurement used in 3D modeling and printing. This specifies what is used for the coordinates—for instance, millimeters or inches.

Z height The distance between the tip of the nozzle and the print bed. This is adjustable and is important for adhesion.