The print sticks to the vat's FEP film

Symptom

When it finishes, the part or a sheet of cured resin is stuck to the film at the bottom of the vat instead of the build plate. Nothing is left on the plate, or only the bottom layers or the supports.

Likely causes, from most to least likely

1. Levelling or the zero position is wrong, so the first layer bonds more to the film than to the build plate.
2. Not enough exposure: the bottom layers do not bond, or the normal layers are underexposed or far below the bottom layers.
3. Peeling is too fast or has too little wait time, so the suction of the film beats the bond with the build plate.
4. The build plate is too smooth or not flat.
5. The resin or the room is cold.

Checks to tell which one it is

• Look at what is left on the plate: if nothing, check levelling and bottom layers; if the bottom layers are there and the rest is on the film, suspect the normal layers.
• If the supports stayed on the plate and the part is in the vat, the supports failed: see that sheet.
• Check the levelling and that the build plate has no play.
• Measure the temperature next to the printer and check whether the build plate is very smooth.

Before you start

Uncured resin irritates skin and eyes: wear nitrile gloves and safety glasses, ventilate the room and do not look at the UV light. Before taking anything apart or cleaning it, switch the printer off and unplug it, unless a step says otherwise. If in any doubt, stop and ask a professional.

Step-by-step fix

1. Carefully remove what is stuck to the film

   Wearing nitrile gloves, take out the vat and pour the resin into a separate container, not mixed with fresh resin. With the vat flat, peel the sheet off with your fingertips starting at the edges, never with your nails, or use a plastic scraper. Do not use metal scrapers: they scratch the film.

   Check: The film is smooth with no residue stuck to it.

   If that does not fix it: If the film is marked, dented or has a hole, replace it before printing (resin leak and torn film sheet).

2. Make sure no debris is left

   Filter the resin and check the bottom of the vat: no piece of hardened resin should remain before the next print.

   Check: There are no pieces floating or stuck to the film.

   If that does not fix it: Follow the cured debris in the vat sheet.

3. Re-level

   The most common cause is a wrongly set zero position. Repeat your printer's levelling or calibration and save the new position.

   Check: On the next print, the bottom layers stay on the build plate.

   If that does not fix it: Check the exposure.

4. Adjust the exposure

   Use the official profile for your resin and run an exposure test. If only the bottom layers stay on the plate, raise the normal layer exposure or use transition layers; Phrozen suggests a 20% increase on some of its models. If nothing sticks, raise the bottom layer exposure.

   Check: The part keeps growing on the build plate after the bottom layers.

   If that does not fix it: Peel more slowly.

5. Peel more slowly

   Lower the lift speed and add some wait time after the light turns off or rest time between layers. As a guide, Phrozen suggests a lift speed below 40 mm/min.

   Check: The part separates from the film at every layer without sticking.

   If that does not fix it: Check the build plate and the temperature.

6. Prepare the build plate and the room

   If the build plate is very smooth, some manufacturers advise sanding it (Phrozen uses 80-grit sandpaper). Check with a ruler laid diagonally against the light that it is flat, and print in a warm room.

   Check: The plate is evenly rough and flat, and the temperature is stable.

   If that does not fix it: Contact the manufacturer's support with photos of the build plate, the film and the part.

Prevention

• Check the film and the build plate before every print.
• Never use metal tools on the film.
• Run an exposure test every time you change resin.

Still not fixed?

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Printers it applies to

Any resin (MSLA/SLA) 3D printer, from any brand.

Official sources

This guide summarises the official documentation linked here:

• Removing and object stuck to the bottom of the tank · Prusa Research
• How to Remove the Cured Resin Stuck on the FEP Film? · Phrozen
• Why Is There Only a Thin Layer on the Build Plate? · Phrozen
• Why Nothing is Sticking to the Build Plate? · Phrozen