Before changing exposure, photograph the build plate exactly as you found it. A bare plate, a raft with support trunks, and a nearly complete part with one missing feature point to failures at different stages. The cured patch in the vat alone tells you little about which stage went wrong.
Stop the job and follow the printer maker’s failed-print cleaning procedure. Account for cured debris before the platform descends again. Prusa’s SL1 guidance calls for stopping promptly to avoid film damage. Use the resin’s specified protective equipment when handling uncured material. Prusa first-layer failure · Formlabs resin care
| On the platform | First place to look | One discriminating check |
|---|---|---|
| Nothing, with a flat cured shape on the film | Initial plate adhesion | Return to the printer maker’s plate setup and a known-good file/profile. A failed foundation gives you no evidence about the model’s support tips. |
| Raft and intact support trunks, model missing | Contact between model and supports | Find the earliest model islands and inspect whether support tips actually reach them. Compare the contact area as the model broadens. |
| Most of the model, one isolated feature missing | That feature’s first independent layer | Step backward from the missing tip or ear until it first appears. Look for a connection to earlier cured material. |
Diagnose one failed feature
Take a figure with a projecting elbow. In the finished model the arm joins the body, so the elbow looks supported. In build order the elbow may appear several layers before the connecting upper arm. If the preview shows a disconnected patch at that point, adding supports elsewhere on the torso leaves the same elbow stranded. Place support where that feature first appears, then step forward until it joins the body. Anycubic describes both unsupported islands and insufficient contact at the top of a support. Anycubic’s supports-only diagnosis
If intact tips cover a broad cross-section but the whole part detached, compare orientations that reduce the sudden area change or redistribute the contacts. Prusa describes detachment with supports left on the platform and identifies inadequate supports and the weight of the object among the possibilities. Record which change you made before the next attempt. A successful reprint after changing six settings gives you little guidance the next time. Prusa on models detaching from supports
For a flat disk on the film and a completely bare platform, follow the first row. Phrozen documents that symptom separately for its release-film printers. Its procedure is model-specific, so use the instructions for your machine when clearing the tank or setting the plate. Phrozen build-plate adhesion diagnosis