Resin print does not stick to the build plate

Symptom

When the print finishes, the build plate comes up empty or the part is partly detached. Sometimes a sheet of cured resin is left stuck to the bottom of the vat, or the part drops into the resin halfway through the print.

Likely causes, from most to least likely

1. The build plate is badly levelled, loose or too far from the film, so the first layers are not pressed against it.
2. Bottom layer exposure is too short for that resin, for the size of the part or for the room temperature.
3. The build plate is greasy or has resin residue, or it is too smooth for the resin to grip.
4. The resin or the room is cold.
5. The face resting on the plate is too small, or there is no raft or not enough supports, so it cannot withstand the force of each layer peeling off the film.
6. There is cured debris in the vat, the film is cloudy or damaged, or the resin is contaminated with alcohol, so the light does not cure properly.

Checks to tell which one it is

• If a cured sheet is stuck to the film, the resin is curing: the problem is adhesion (levelling, bottom layer exposure or build plate).
• If nothing has cured on the plate or in the vat, the screen or the UV light may be failing: see the LCD screen and UV light sheet.
• With the printer stopped, push the build plate: it must have no play. Also check that the vat sits flat and is firmly fastened.
• Lay a ruler diagonally across the plate against the light: if light shows underneath, the plate is not flat.
• Print a manufacturer's test file with its profile: if it prints fine, the problem is in your file or your settings.

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. Clean and degrease the build plate

   Wearing nitrile gloves, remove the build plate, scrape off residue with the spatula and clean it with isopropyl alcohol until no grease remains. Let it dry completely before refitting it: alcohol dripping into the vat stops the resin from curing properly.

   Check: The surface is clean and dry, with no residue stuck to it.

   If that does not fix it: Check the fastening and levelling in the next step.

2. Tighten and re-level

   Tighten the knob or screws holding the build plate and check the vat screws. Then repeat the full levelling or calibration without skipping steps, even if nothing has changed since last time.

   Check: The build plate has no play and the calibration finishes without errors.

   If that does not fix it: Follow the build plate levelling sheet. If the plate is not flat, contact the manufacturer.

3. Adjust bottom layer exposure

   Load the official profile for your resin and printer: bottom layers need much more exposure than normal layers. As a guide, Phrozen suggests raising it by around 20% for large parts or a full build plate.

   Check: The bottom layers stay on the plate and no cured sheet is left on the film.

   If that does not fix it: Run an exposure test with that resin and check the temperature (cold resin sheet).

4. Give the part more support

   In the slicer, put a large flat face on the build plate, or use a raft with the part slightly tilted and enough supports. Lower the build plate lift speed; as a guide, Phrozen suggests less than 40 mm/min.

   Check: The raft or base stays whole on the plate, with no lifted corners.

   If that does not fix it: Check the vat and the film.

5. Clean the vat and check the film

   Wearing gloves, filter the resin and remove any cured debris from the film with your fingertips or a plastic scraper, never a metal one. Clean the film as your manufacturer indicates (Prusa, for example, uses warm soapy water and never alcohol or acetone). Replace the film if it is scratched or cloudy. If the resin got mixed with alcohol, use fresh resin.

   Check: The film is clear and smooth, and the resin has no bits in it.

   If that does not fix it: Try improving the grip of the build plate.

6. Sand the build plate if it is too smooth

   If everything else is fine, some manufacturers recommend sanding the build plate so the resin grips better: Phrozen uses 80-grit sandpaper. Clean it with alcohol afterwards and re-level. Only do this if your printer's manufacturer recommends it for its plate.

   Check: Running your fingertips over it, the whole surface feels evenly rough.

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

Prevention

• Clean and dry the build plate after every print.
• Check the film and filter the resin after any failed print.
• Always use your resin's exposure profile and print in a warm room.

Still not fixed?

Tell usi3d's AI about your case: choose your printer, describe what you see and add photos if you like. It proposes checks step by step, with their sources.

Tell the AI about your case

Printers it applies to

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

Official sources

This guide summarises the official documentation linked here:

• Non-adherence · Formlabs
• First layer does not stick (SL1/SL1S) · Prusa Research
• Prints breaking away from the platform · Prusa Research
• Why Nothing is Sticking to the Build Plate? · Phrozen