Setting Up a Resin Printer

Three setup mistakes are easy to make in the first hour: a cold room, a build plate that was never leveled, and exposure settings meant for a different resin. This lesson walks through the setup in the order you will do it. If you have not met the parts yet, read Parts of a Resin Printer first.

1. Pick the room before you pick the shelf

• Ventilation. Prusa's resin guidance says resin produces fumes and the room should be kept ventilated during printing. The Formlabs Grey Resin SDS says to use it only with adequate ventilation; check your own resin's SDS. See Resin PPE for what that means for your own resin.
• Out of the light. Resin cures under UV light, sunlight included (Prusa). Keep the printer and the resin away from windows and direct sun.
• Away from food. Formlabs says not to eat, drink or smoke in the printing work area. A kitchen or a dining table is the wrong place.
• Out of reach of children and pets. Prusa says to keep resin out of their reach.

For the rest of the room (power, shelving, a spill tray, where the wash station goes), see Setting Up a Safe Workspace.

2. Check the temperature

Cold resin is thick. Elegoo explains that in cold weather resin viscosity rises and it flows less, which shows up as supports tearing off the model or the base peeling away from the build plate. Elegoo gives 25 to 35 °C as the optimal ambient range and says prints may fail below 20 °C Maker spec. That is Elegoo's figure for its printers and resins; check your own printer's manual for its range.

Elegoo's cold-weather advice, for its own resins: print in a warmer room, warm the resin bottle in water before printing so the resin itself reaches 30 to 40 °C Maker spec, and adjust exposure and lift settings. Do not put a resin bottle on a heater or near an open flame; the Formlabs Grey Resin SDS says to store it away from heat, open flames and other sources of ignition.

Storage is a separate question from printing, and makers do not agree on one range. Prusa's general advice is to store resin at 18 to 32 °C Rule of thumb, warning that cold causes gelation. Formlabs gives 10 to 25 °C for best shelf life of its resins Maker spec. Use the figure on your resin's label or data sheet.

3. Gear up before you open anything

Put on chemically resistant gloves and eye protection before you touch the vat, the build plate or the resin bottle, and leave them on until everything that touched liquid resin is clean. The exact gloves, eye protection and respirator advice come from your resin's SDS, which is why Resin PPE comes second in this track.

4. Level or calibrate the build plate

The first layers have to be pressed flat between the build plate and the film at the bottom of the vat. If the plate is not parallel to the screen and at the right height, the first layers will not bond and the print ends up stuck to the film.

How you do this depends entirely on the printer. Some use a guided setup on the touchscreen; some level automatically with a sensor; many older and budget machines use a paper method. As one example, Elegoo's Mars Pro procedure is:

1. Loosen the build plate screws with the supplied wrench.
2. Lay a sheet of A4 paper on the screen, under the build plate.
3. Home the Z axis from the menu and let the plate come down onto the paper.
4. Center the plate and tighten the screws in the order the guide gives.
5. Pull the paper. If it will not move, raise Z in 0.1 mm steps Maker spec; if it slides freely, lower Z by 0.1 mm. Slight resistance means the plate is set.

That is one maker's method for one model. Follow the leveling steps in your own printer's manual, including whether the vat stays in or comes out while you level.

5. Shake, then fill the vat

• Shake the bottle. Pigments and fillers settle. Prusa's general advice is to shake the bottle for about 10 seconds with the lid tightened Rule of thumb, and notes that some casting or dental resins should not be shaken because of air bubbles. Formlabs says to check for abnormal thickness or clumps and to shake or stir as directed. Follow the label.
• Pour slowly and stop at the line. Formlabs warns not to exceed the tank's maximum fill line.
• Keep resin in its own containers. Prusa says to keep resin in its original sealed container or, if that is damaged, an opaque plastic bottle, and never in a drink bottle; if there is truly no alternative, Prusa says to label it clearly.

6. First print: the maker's test file

Start with the test model that came with the printer, not a model you downloaded. It has known geometry and supports, so if it fails, the cause is setup, not the model.

Check one thing before you press print: that the file's exposure settings match your resin. A bundled file is set up for the resin the maker had in mind, and Prusa says to always use the recommended exposure times for the resin you are using. Resin Exposure Settings explains how to find the right values.

When the print finishes, the part is still coated in liquid resin and is not done. It goes to washing and curing next: see Washing and Curing Resin Prints. The vat, film and plate need attention after every print: see Vat, Film and Build Plate Care.

Setup checklist

Check	Where the answer comes from
Room ventilated, out of sunlight, away from food	Your resin's SDS and the printer manual
Room and resin warm enough	Printer and resin maker's range Maker spec
Gloves and eye protection on	SDS section 8
Build plate leveled or calibrated	Printer manual
Resin shaken, vat below the max line	Resin label, vat marking
Exposure set for this resin	Resin maker's profile, then an exposure test