Warping, curling and split rafts
Warping is when a raft, base or flat section curls, lifts or splits away from the plate. You might see a lifted edge, a gap under the raft, or the bottom layers splitting just above the plate. Cured resin shrinks a little, and that stress builds up in thin or heavily cured areas.
Most likely causes (in order)
- Thin rafts / over-exposed bottom layers: Shrinkage stress concentrates in a thin, heavily cured raft.
- Weak adhesion at the edges: If the edges aren't gripping well, stress peels them up.
- Cold resin or room: Cold resin is thicker and cures less consistently.
- Large flat cross-sections: Big flat areas printed parallel to the plate are more likely to curl.
Settings to change
| Setting | Change | Why |
|---|---|---|
| Raft | Use a thicker raft with a chamfered edge | Reduces curling stress (Lychee: Split-Rafts). |
| Bottom exposure | Fine-tune; avoid extreme over-exposure | Excess cure shrinkage induces stress. |
| Resin temperature | Keep resin/room ~20–30 °C | Cold resin is viscous and under-cures. |
Exact values depend on your printer and resin. Start from the resin maker's recommended settings and change one thing at a time.
Quick checklist
- Use a thicker raft with a chamfered edge
- Fine-tune bottom exposure; avoid extreme over-exposure
- Keep resin and room roughly 20–30 °C
- Angle flat parts instead of printing them flat on the plate
- Clean and level the plate
FAQ
Why is my resin raft peeling off the plate?
Usually shrinkage stress in a thin or over-exposed raft, plus weak adhesion at the edges. A thicker chamfered raft and tuned bottom exposure help.
Do flat resin prints warp?
They can. Large flat areas printed parallel to the plate are prone to curling. Angling them usually helps.
Not sure which one you've got?
Upload 1–4 photos of the failed print and PrintCleric ranks the likely causes and tells you exactly which settings to change, with sources.
Sources
Related fixes
- Layer separation / delamination in resin prints
- Failed supports: model stuck to the FEP, only supports printed
- Nothing on the build plate (print stuck to the FEP)
- Suction cups and blowouts (volcanoes) in hollow resin prints
- Elephant's foot (flared bottom layers)
- Blooming and over-exposure: soft details and rough surfaces
Wear nitrile gloves and eye protection when handling uncured resin, and work in a ventilated space.