3D Printing

Just like a standard paper printer, you will always need to purchase materials and supplies for your 3D printer — whether fused deposition modeling (FDM) or stereolithography (SLA/resin). There are so many different kinds of materials for 3D printing out there.

FDM printers use spools of filament. This filament is generally plastic-based, and gets melted and printed out to create a design. There are some filaments that are more popular than others:

• PLA (polylactic acid): this corn-based filament is the most commonly used in FDM printing, and is recommended when starting out on a 3D printer. PLA is easy to use and doesn’t necessarily require a heated print surface. It provides good detailing on a 3D print as well, is good for parts. PLA is also used for food products, but not be great for eating. It can also be a little brittle, so it’s not recommended for designs that need to be very sturdy. It doesn’t hold up well to sunlight or heat exposure.
• PET, or PETG (Polyethylene Terephthalate-Glycol): PET, or PETG can be beneficial for a wide range of designs. PETG is sturdy and durable, and holds up well to heat and chemicals. It is also water resistant. However, PETG can be “stringy” — that is, as a design prints, you might see thin strings of filament on your object. These can be taken off, or melted with a heat gun, but sometimes cause minor issues in printing.
• ABS (Acrylonitrile butadiene styrene): ABS is almost as commonly used in 3D printing as PLA, but might not be the best for libraries. While ABS is strong and provides a smooth print, it also omits a strong smell and requires control over the temperature of the 3D printer and its surrounding area. If you do use ABS, especially in an enclosed space, be sure to filter out the fumes.
• Nylon: Nylon filament is incredibly durable and strong, and is great for prototyping and making hinged and functional parts. Nylon prints white, but can absorb color with different dyes. However, nylon also absorbs water, and must be kept completely dry. Nylon-based prints need to be completely dry before they are used. Nylon also requires a high temperature — 250 degrees — and not every nozzle can get that hot.
• PVA (Polyvinyl Alcohol): PVA is a support filament that prints clear or with a slightly yellow tint. This filament is mostly used when using more than one extruder for printing (for more information, please see All About FDM 3D Printers). PVA is excellent for 3D designs that need a lot of supports — like a design that is very detailed — as it’s water-soluble and melts away with warm water, leaving little to no trace on the design.
• Composite filaments: There are several filaments on the market that aren’t only made of plastic. Composite filaments are designed to look like stone, wood, metal, clay, and other objects. Oftentimes these filaments contain powdered elements of the object they are meant to look like.

Tips & Tricks for FDM Filament
• It is important to know the melting temperature for any and all filaments and adjust your printer accordingly when loading and unloading filament, and preheating for printing
• Keep all of your filament stored out of light and sun, and ideally in an airtight container. However, the bag or box your filament came in is fine as well. Leaving your filament sitting out exposes it to light and moisture, and can damage and degrade the material.
• When preparing your filament for loading into a printer, always cut it at an angle
• Consider having a spot on your website that easily and briefly explains to patrons what each filament does.
• You might want to price each filament differently, depending on cost.

SLA/Resin printers work differently from FDM, and thus require a different material. Instead of spools of filament, resin cartridges are used. Resin is excellent for molds and prototyping, but also provides excellent detail. Unlike plastic filament that comes in many colors, liquid resin is limited to shades like white, gray, black, and clear (a great option for a transparent print!). However, some SLA printer manufacturers have resin that can have pigment added for more colorful prints. Some manufacturers also make resin that is flexible, allowing you to make designs like stamps, or even parts of binoculars.

There are different types of resin available:
• Standard resin
• Pigmented resin
• Flexible resin
• Silicone resin

While FDM is the most popular kind of 3D printing, SLA — or stereolithography — is becoming a popular choice for professionals, hobbyists, and libraries alike. This type of printing is great for prototyping, but can be useful to patrons looking to make their own tools and designs, or want a print that requires high detail or a smooth finish. These prints are also watertight, meaning that water cannot pass through the object.

SLA printing uses liquid resin and laser technology to build a 3D object, and requires a different process than FDM. Resin prints need to be washed with isopropyl alcohol, then cured using UV light. While resin printing is different from your standard 3D printing process, the software and design process are similar.

Did You Know? SLA was actually the first type of 3D printing technology!

Important parts of the resin printing process include:

Build plate: Also called a platform. This is where the design will be built, layer by layer. However, because resin printing involves a liquidized material, the printing process is different from the standard 3D printing process. The build platform is found at the top of the printer, and is moved up and down into a tank containing liquid resin, where the resin will harden.
Post-Processing: An integral part of a successful resin print is post-processing. A completed print will be placed into a tank containing isopropyl alcohol, a process that takes anywhere from 15-30 minutes. Once that process is complete, the object then cures in a separate UV light tank, which can take up to an hour depending on the object’s size and type of resin used for the print.
Material: Various types of liquid resin are used with an SLA printer.Resin is excellent for molds and prototyping, but also provides excellent detail. For more information, please see Materials for 3D Printing.
Resin cartridge holder: This is where your resin cartridges are placed. It’s important to follow instructions when installing a cartridge, so that the resin will flow properly to the tank.
Tank: Where the liquid resin will flow. This is where the build plate will go to start building the design. Resin tanks occasionally need to be replaced.
Information Screen: Most resin printers will have an interactive screen that you can use to print, reprint, or access settings.
Software: Most of the time you will be using the software that is recommended by the manufacturer of your printer. However, you may also elect to use alternate programs for printing. Please see Introduction to 3D Printing for Libraries for software recommendations.
Gloves: While it sounds simple, it is incredibly important to wear gloves when handling resin prints. After post-processing is complete, you may remove the gloves.

Tips & Tricks for SLA 3D Printing

• You will need a good scraper to remove the printed object from the build plate. It’s important to be gentle but forceful.
• Clean off your build plate immediately after removing an object so that the resin doesn’t harden.
• Most 3D printing software uses millimeters to size objects. Always be sure to communicate this to patrons who want to use the printer to ensure proper sizing.
• Thingiverse is your best option for finding 3D objects to print.
• Supports are very important with resin printing, and it’s always better to use them.
o Supports can be tricky to remove, so if you’re printing for a patron, you could have them remove the supports on their so that you don’t damage the object
• Trial and error is ultimately your best method for learning about your printer. Don’t be afraid to make a mistake, and know that every problem is fixable.

For more detailed information about your 3D printer, it is best to consult the manufacturer’s guides and website. Most manufacturers also have user forums where you can ask questions or simply read answers and solutions to problems you might encounter.

The most commonly used 3D printer is FDM, or fused deposition modeling. This is the type of printing that most of us think of when talking about 3D printing. FDM printers come in all different shapes and sizes, and each one will operate differently. There are, however, standard parts and accessories for every 3D printer.

Build plate: Ultimately where your project is built, and a part that could make or break your print. The filament is melted onto the surface of the build plate, and is built bottom-up. Not all surfaces look exactly the same, so it’s important to know the type of surface you’re working with. In addition to the build plate and surface on your printer, you can purchase adhesive sheets that sit on top of the build plate. Adhesive sheets can be helpful, as you can remove them from the build plate and gently twist them to more easily remove your print.
• Glass is a common surface, and helps provide a smooth finish for your prints. However, many glass surfaces require blue painter’s tape, or a glue stick, or even a spritz of aerosol hairspray so that the print can adhere properly. The type of adherence aid you use depends on the type of filament you’re working with.
• PEI is a surface sheet that is placed on the build plate, and has great adherence right out of the gate. However, this great adherence could mean that filaments like PETG can get a little stuck to the surface, and you may face difficulty removing the print.
• Aluminum surfaces can also be build plates on their own, but also pair well with adhesive sheets
Working with your Build Plate
It’s important to maintain and clean your build plate; for most filaments, a clean surface means better adherence (however PETG might actually adhere better to a slightly dirty build plate). The build plate can also get extremely hot, so use caution while handling the printer after a job.

Extruder: This is the most important part of your printer. It contains a motor and other mechanical pieces — this is called the cold end. It also contains a nozzle (and other parts) — the hot end — where the filament comes out onto the build plate. The filament is placed into the cold end of the extruder, melted, and then pushed out through the nozzle. Basically, it’s a mechanical hot glue gun! Some 3D printers have two or even multiple extruders so that two different kinds of or color filaments can print at one time. This is sometimes called “dual-extrusion.”

A word about nozzles:
Like your build plate, it’s important to clean and maintain your extruder’s nozzle. Filament may build up on your nozzle, and keeping it clean will lead to fewer filament jams for your printer. Depending on your plan for your printer, you may also want to invest in different nozzle sizes. Nozzle diameters range from 0.25mm to 1mm, with smaller nozzles providing more detail and larger ones creating a faster print. A standard nozzle diameter is 0.4mm, with 0.35mm being another common type.

Filament spool: Every 3D printer will have a spot to place the filament so that it can be easily loaded into the extruder. Sometimes this is a spool inside or outside the printer.
Information Screen: Depending on your printer, this is where you can select files for printing, load/unload filament, track the progress of your print job, view the temperature of the nozzle, & more. This screen might also contain a slot for an SD card to print your design.
Software: Most of the time you will be using the software that is recommended by the manufacturer of your printer. However, you may also elect to use alternate programs for printing. Please see Introduction to 3D Printing for Libraries for software recommendations.
Material: The material used for FDM is plastic-based filament, generally found on a reel. There are many different filament types, including some that are mixed with wood and metal. Please see Introduction to 3D Printing for Libraries for material information.

Tips & Tricks for FDM 3D Printing

• You might need certain tools to help you lift a 3D print off the build plate. We find that a metal or plastic label scraper works well for this — just be gentle, as some prints could be brittle or thin and may break easily.
• Most 3D printing software uses millimeters to size objects. Always be sure to communicate this to patrons who want to use the printer to ensure proper sizing.
• Thingiverse is your best option for finding 3D objects to print.
• Filament jams in your extruder are inevitable, so be sure to read your manufacturer’s solutions for these jams, as not every extruder is the same.
o However, some of the time you can clear a jam by heating up the extruder and pushing through new filament.
• Trial and error is ultimately your best method for learning about your printer. Don’t be afraid to make a mistake, and know that every problem is fixable.

For more detailed information about your 3D printer, it is best to consult the manufacturer’s guides. Most manufacturers also have user forums where you can ask questions or simply read answers and solutions to problems you might encounter. You can also visit MatterHackers for filament and in-depth guides to general 3D printing.