Resin (SLA) Printer Tutorial
Resin printers, or SLA (stereolithography) printers, are a type of 3D printer that uses UV light to solidify a liquid resin into a solid model. Because they use light, resin printers can have much higher precision than FDM or filament-based printers. Resin printers are ideal for miniatures, keycaps, and other small, high-detail parts.
The typical precision of our Elegoo Mars 3 is 0.1mm to 0.05mm in the Z direction and 0.035mm (35um) in the X and Y directions. Some resins suffer from shrinkage so their accuracy may not be as high as FDM printers.
This tutorial assumes a basic familiarity with PrusaSlicer and FDM printers.
Important: The resin printer setup at Seattle Makers is not yet ready for member use. Resin printers require unique safety precautions and they will require a certification and PPE to operate. If you absolutely NEED to print something RIGHT NOW, ask Sam K. for guided use.
We will use PrusaSlicer to slice the 3D files, and another software called UVTools to export them to the printer.
Install UVTools (copy winget command into terminal)
Now we'll install the printer we are using into PrusaSlicer.
Open PrusaSlicer and install the Prusa SL1 printer in the config menu.
Close PrusaSlicer and open UVTools.
Go to Help -> Install profiles into PrusaSlicer.
Select all print profiles. Select "Elegoo Mars 3" under Printer Profiles. Install the profiles.
Re-launch PrusaSlicer.
In the top-right corner, make sure "expert mode" is selected. Change the printer to "Elegoo Mars 3."
Before we open a file, we need to adjust some settings.
Select "Materials." Change "Exposure time" to 3 seconds and "Initial exposure time" to 10 seconds. Different types of resin may require different exposure times; seek the manufacturer's recommendations.
Select "Material printing profile." In both columns, set "Delay before exposure" to 0.5 seconds. Set "Tower hop height" to 5mm. Turn off "tilt".
Models in this tutorial are from "Kitsune Collection" by MZ4250 on Printables.com.
Save the file - sometimes PrusaSlicer can crash on import, and we don't want to lose any settings changes.
Return to the "Platter" and drag and drop your model file into the PrusaSlicer window. PrusaSlicer supports importing these file types: 3MF, STL, STEP, OBJ, AMF
Adjust the model's size to taste.
Rotate the model so there are no flat surfaces parallel to the buildplate. Resin printers don't like having to pull up a bunch of new material at once; the surface will be warped and the print may fail. Layer lines will be more visible as the printer has less resolution in the Z direction, but it's a tradeoff.
Make sure you have supports enabled everywhere and the pad below the object.
Save the file before you slice.
When you are ready, click "Slice now." It may take several minutes, depending on your computer.
PrusaSlicer will automatically generate supports where needed. It might not seem like some of them are necessary, but they are much easier to remove than filament supports, so it's better to have too many than too few.
If it looks good and doesn't throw an error, click "Export" and select a file location.
PrusaSlicer will give a time estimate, but it's rarely correct.
PrusaSlicer will export a .SL1 file, which the printer can't read. We need to open it in UVTools to convert it to a format the printer can read.
Open UVTools and open the .SL1 file.
The supports won't show up in the viewport, this is normal.
Convert the file to "Chitubox CTB (Encrypted)."
Save the .CTB file to the printer's USB drive.
PrusaSlicer's time estimate is often very inaccurate - often the real time is double or triple what it says. UVTools will give a more accurate estimate but add an hour at least for safety, and don't forget post-processing.
Be sure to wear nitrile gloves, safety glasses, and an organic vapor respirator whenever handling liquid resin or uncured parts or trash.
Open the fume hood and turn on the evacuation fan (on the right side). Remove the lid of the printer.
If the printer's basin is empty:
Remove the lid of the printer.
Use the touchscreen to raise the build platform halfway up the tower, so it's easily accessible.
Wipe down the bottom and sides of the basin with KimWipes and isopropanol (IPA). Ensure there are no pieces of solid resin on the film.
Remove the magnetic buildplate and clean both sides with KimWipes and IPA. Clean the build platform as well.
Replace the magnetic buildplate on the print platform (orientation doesn't matter) and align it.
Important: Ensure the basin screws are tight.
Shake the resin bottle thoroughly. Check the expiration date and ensure that it is at room temperature or warmer.
Open the bottle and pour resin into the basin almost up to the fill line. It's OK to have too much resin for your print, but it's not OK to not have enough or to go above the fill line.
Put the lid back on the printer and ensure it is aligned and in place.
Insert the USB drive and tap "Print." Find the file you want to print, and press the red start button.
Close the fume hood and wait for the print to finish!
Be sure to wear nitrile gloves, safety glasses, and an organic vapor respirator whenever handling liquid resin, uncured parts, or trash.
Resin prints need to be washed and cured for a few minutes after printing.