Quick diagnosis
Resin failures show up in different ways: a soft or unfinished surface, a warped or oversized part, a print that let go of the build plate, or supports that gave out partway through the job. Because SLA and DLP printing works nothing like filament extrusion, treat this as its own diagnostic path rather than borrowing fixes meant for FDM problems elsewhere on this site.
1. Check exposure time first
Exposure time is the most common source of resin failures and the first setting worth checking. Too little exposure leaves prints soft, tacky or missing fine details, and can cause holes or delamination between layers because each layer never fully bonds to the one below it. Too much exposure cures extra resin around every shape, which shows up as warping, oversized features and a loss of dimensional accuracy. Start from the resin manufacturer’s tested profile for your printer and light source, then adjust exposure in small steps rather than guessing.
2. Inspect the FEP film
The FEP film at the bottom of the vat has to release each cured layer cleanly, and a scratched, cloudy or punctured film gets in the way of that. Deep scratches create weak points where suction is uneven, which can pull a print off the build plate mid-job, and a puncture lets resin leak underneath the film onto the LCD or light source below it. Hold the vat up to a light and check for scratches or haze, and replace the film if a print failed recently for no other obvious reason.
3. Confirm resin temperature
Cold resin is thicker than the manufacturer intended, and that extra viscosity slows how fast it flows back across the build plate between layers. When resin can’t level out in time, a layer can print starved of material, which weakens interlayer bonding or lets a part pull away from its supports. Most resins are formulated to perform well in roughly the 20 to 28 degree Celsius range; if your workspace runs colder, warm the bottle or bring the room up to temperature before starting a long print.
4. Review orientation and supports
A model oriented flat against the build plate, or resting on too few and too-thin supports, is a likely candidate to detach during the peel step, when the plate lifts and the film releases the cured layer. Add more contact points under overhangs and thin sections, thicken supports on parts that flex, and tilt large flat faces slightly instead of printing them dead flat against the plate. This shortens the distance resin has to travel to refill each layer and gives the peel force less surface to pull against at once.
5. Do not skip the wash and cure steps
A print that comes off the plate looking fine can still fail at the wash and cure stage. An incomplete IPA or water wash leaves uncured resin on the surface, which stays tacky and can gum up supports during removal. Skipping or shortening post-cure leaves a part below its intended strength even though it already looks solid. Follow the resin manufacturer’s wash time and post-cure guidance for that specific resin and light source, and re-cure anything that still feels soft or flexible after its first pass.
Resin print failure checklist
- Exposure time matches a tested profile for the resin and light source.
- FEP film is clear and free of scratches or punctures.
- Resin and room temperature sit within the recommended range.
- Supports give solid contact under overhangs and thin sections.
- Wash removes all uncured resin before cure.
- Post-cure time matches the resin manufacturer’s guidance.
A scratched or punctured vat film is also covered in FEP film replacement. Wash-and-cure hygiene is part of the routine described in a resin printer’s maintenance schedule. If the part printed successfully but shows uneven or misaligned layer lines rather than an outright failure, that has its own diagnostic path. For a printer-specific rundown of what’s documented so far, see the Elegoo Mars 5 Ultra error index.