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.