Resin Printing

In-person resin course required. Resin is mildly toxic and a skin allergen.

How to use the Prusa SL1S Speed and CW1S safely. Questions or breakages: Alex Lopez on Slack — report as soon as possible.

Safety

  • Safety glasses and nitrile gloves. Once you've started, only touch things inside the cabinet.

  • After removing gloves, wash hands with soap and water. Never IPA or acetone on skin — it drives resin deeper.

  • Lift bottles and equipment with both hands.

  • Don't leave resin on taps or door handles.

The two cabinet rules


Rule

Stays in the cabinet (tools)

Never cure. Rinse in the cleaning solution until resin-free, wipe dry with paper, put back. Cured tools are ruined. Toolbox stays clean and dry.

Leaves the cabinet (paper, gloves, rinse water)

Always cure, then dispose of it. Cured rinse water goes down the wet room sink.

Tools: filter, funnel, tweezers, Allen keys, scraper, tank cleaning tool, syringe.

Protect the printer

  • Splash guard every time you move resin in or out — keeps resin out of the electronics.

  • Before starting, check no failed print is stuck in the tank (it can crack the display).

  • Tank cleaning cycle after every print.

Tank (vat)

  • Never IPA on the FEP film — it goes cloudy.

  • Emptying: filter + funnel back into the bottle; rinse and dry them straight away.

  • Cleaning the film: wipe very gently with clean paper, then wash gently with fingers and detergent in the wet room.

  • Tank must be 100 % dry before adding resin.

Slicing (PrusaSlicer)

  • Tilt the model 45° to avoid suction and improve quality.

  • The slicer works upside down.

  • Avoid horizontal faces at all costs; avoid horizontal edges where possible.

  • Hollow models (less resin, faster curing, fewer supports) and add a drain hole near the bottom.

  • Under-exposure: failed prints or lost detail. Over-exposure: thickened parts, lost detail.

  • Common failures: too few supports, miscalibration, resin mixed with IPA. If prints fail, calibrate.

Printing

  1. Gloves on. Insert your USB stick before touching any resin.

  2. Main power switch at the back, on button at the front.

  3. Splash guard on.

  4. Run the scraper gently along the bottom. Resistance → run a tank cleaning.

  5. Stir the resin for one minute.

  6. Splash guard off. Start your file; the machine tells you how much resin to add.

  7. Too much? Splash guard on, remove the excess with the syringe back into the bottle. Rinse the syringe in the solution, dry it — don't cure it. Cure the paper.

  8. Splash guard off, let it start.

Finishing

  1. Take your USB stick before handling resin.

  2. Splash guard on.

  3. Let resin drip off the model back into the vat; pour any trapped resin back.

  4. Run the tank cleaning program.

  5. Wash the model and the cleaning film in the CW1S — 2 cycles. The wash solution can be reused many times; only replace it when it feels goopy.

  6. Let the model dry a few minutes on paper.

  7. Cure ~20 minutes.

Cleaning up

  • Wipe the printer and surfaces with IPA and paper; cure the paper and throw it away.

  • Run a bottom (tank) cleaning when done.

Video material

Unedited clips for future instruction videos.