Resin printers create 3D objects by curing liquid resin layer by layer. The build plate is dipped into a resin tray, creating the object upside down. After a given layer is cured, the build plate is raised slightly for the next object layer to begin curing.
Like traditional 3D printing, objects must be sliced with a slicer (prepped for printing with 3D printing software). You can use almost any common 3D file type (STL, OBJ, etc) just make sure the final sliced file type is appropriate for your 3D printer.
Once your object is sliced, load it onto the resin printer (often via USB or microSD card). The object can then be selected for printing.
Some 3D printers use UV light to cure each layer. These printers are sometimes called UV printers. They feature a special UV light panel for layer curing.
There are also 2D printers that use UV curing ink.
There are several types of resin printers, but two dominate the market today: Digital Light Processing (or DLP) printers and Stereolithography (known as SLA). Each uses liquid resin to create objects layer by layer.
Most 3D printers use photopolymer resin. There are a variety of manufacturers with everything from opaque to translucent colors. Double-check with the printer manufacturer to know which type of resin is recommended for your device.
Most casual resin printers have a limited build plate size of around 10cm across. Industrial resin printers provide much larger build platforms for more practical applications. These machines come with an added cost.
The cure time on resin printed objects is determined in the slicing software. You can choose how long each layer is cured by adjusting the exposure time. You may want the initial layers to have a higher cure time to improve adhesion to the build plate.
A typical exposure cycle is around 10 to 15 seconds per layer. The shorter your object, the faster it will print.
Photopolymer resin costs around $20 for 500ml of resin. The exact price will vary between suppliers and depending on resin color/opacity.
Photopolymer resin is not food safe. However, you can 3D print objects with photopolymer resin that can be used to make food safe items through silicone molds and other similar processes.
Resin printers do not work with OctoPrint. The developer has made no indication that resin printer support would be introduced in the future.
They work on fundamentally different principles with unique hardware, firmware, and software that isn't necessary for FDM machines.
Resin printers can sometimes print faster than standard FDM printers. The speed depends on the object size, orientation, and exposure time set for each layer in the slicer settings.
Finishing requirements can vary between photopolymer resins. In most cases, soaking the object in 90% Isopropyl Alcohol for a few minutes will help clean any remaining uncured resin.
On average, resin printing takes about as long as FDM printers. Adjusting the exposure time in the slicer settings will ultimately determine how long your object will take to print.