Resin prints stuck in the vat: diagnosing separation failures

Stop first, print again later

For a print that fails while still in progress, the Formlabs Form 1+ defect page says to cancel it, diagnose the failure, adjust the model or settings, clean the platform and tank, check the mirror and printer temperature, and then try again. Cured fragments call for inspection before another exposure, but do not identify the cause by themselves. The exact sequence, including canceling a job, belongs to the Form 1+ procedure.

This procedure is written for the Form 1+; the page says PreForm 2.20.0 is the last supported version for that machine. For another printer, Formlabs or otherwise, use its own vat-inspection and cleaning instructions. The sequence above helps read the Form 1+ page; it does not replace the steps in your printer's manual.

Before cleaning or retrying, consult the inspection and cleaning instructions for your exact model. The Formlabs pages used here describe a historical Form 1+ workflow and cup analysis in PreForm; they do not provide one cleaning method for every film and printer. The ventilation and safety guide supplements the product-specific safety information for the material being handled.

Pin down where the bond actually broke

Before you touch a setting, look at what stayed on the platform and what stayed in the vat. The Form 1+ documentation separates several observations that look alike from a distance and point to different checks. In the first, nothing adheres to the build platform: the base peeled away partially or fully. In the second, the base printed but the supports did not. In the third, the part was pulled off its supports. In the fourth, a hollow part exploded from a small failure that propagated.

These observations suggest different checks but do not establish a cause on their own. A whole base in the vat matches the case where the base peeled away from the platform; a printed base without supports is a reason to check base thickness. Supports without the part invite a closer look at touchpoints. For a cavity, scattered wall fragments may justify checking orientation and whether PreForm flags a cup.

Record what you see before cleaning. A photo of platform and vat alongside the original file also helps the manufacturer's support team, which the Form 1+ page invites you to contact for certain defects. The troubleshooting hub collects other observation grids you can reuse.

Nothing sticks to the platform: the documented checks

When the entire base ends up in the vat, the Form 1+ documentation names a resin tank that is not clean as the usual culprit. The listed checks are concrete: make sure platform and tank carry no cured resin from a previous build, inspect the tank for gouging or severe clouding, and agitate the resin to re-suspend settled pigment. The same page states that if the tank is crystal clear, base thickness and the fine tuning feature are used to calibrate build platform height on that machine.

Two nuances matter. First, clouding or a gouge does not automatically condemn the tank: the documentation suggests moving the part to another area of the tank before considering a replacement. Second, for very small parts it recommends trying another print location, citing the hinge side of the Form 1+ as the example. That position is specific to that printer and does not transfer.

The relocation and retry suggestion belongs to the historical Form 1+ guide. It does not override your printer’s criteria for discarding a damaged tank. Inspect first; if its instructions require replacement, do not run another print to postpone it. The vat film page helps distinguish consumable families before ordering.

Base without supports, part torn from supports

If the base sits on the platform but the supports are missing, the Form 1+ documentation says the base may be too thin and points to increasing base thickness under advanced support settings. That lead concerns file preparation; it does not rule out other hardware problems. Before cleaning anything, open the project and compare that value with the profile you used when prints were succeeding.

If the supports are intact and the part went into the vat, the same page points to support tips that were not strong enough. The documented leads are increasing touchpoint size and support density, then adding manual supports on a larger part, especially when separation happened in a single area. Looking at where it broke guides where you add them.

For these two observations, the Form 1+ page directs readers to the prepared file and support settings; it does not establish a single diagnosis or a reason to replace the film immediately. Review the supports and break location before deciding what to change. The print supports guide explains touchpoints and density.

Cavities and suction: the cups lead in PreForm

A hollow or concave part can fail when a cup is present, though that observation does not rule out other factors. The Formlabs PreForm page explains that an upward-facing cavity opening can trap air between the part and the tank bottom as the platform lowers. The resulting suction can cause layer separation, structural defects, warping, or print failure; Formlabs also cites risks of resin contamination, tank damage, or spills.

According to the same page, PreForm offers a Show Cups toggle that highlights affected volumes in yellow, reached through the Job Info panel. With multiple models, PreForm 3.32.0 and later add a crosshair icon next to Cup Detected that selects the models with a detected cup. The described fix is to rotate the highlighted area so the opening faces downward or sits at a 5 to 15 degree angle, then regenerate supports once no yellow areas remain.

Two limits to keep in mind. The absence of yellow highlighting is not a full quality certification. And the Form 1+ page on hollow objects without drainage recommends changing orientation or adding a drainage hole, which is done back in your modeling software.

What leftover resin in the vat does not prove

Liquid resin remaining after a job does not, by itself, identify a fault. Cured fragments or a slab attached to the film warrant inspecting the vat, but they do not name the cause. The cited pages connect observations to leads: Form 1+ documentation mentions a dirty tank, platform-height tuning, or print location; the PreForm page describes possible suction from a cavity. Keep the observation separate from the explanation.

The same documents list neighboring issues under separate headings, including holes or fractures, a granular finish, and a mushy part, with their own leads such as mesh, tank damage, or dirty optics depending on the symptom. Do not treat them as separation diagnoses without examining the case. Changing exposure or replacing a tank solely because a fragment remained on the bottom is not a conclusion supported by these pages.

Finally, the pages used describe the Form 1+ and the PreForm workflow. For another machine, the observation logic holds, but every gesture must come from your model's documentation. The steps after a successful print, washing and curing, are covered in the resin post-processing guide.

Sources and limits

• Print defects (Form 1+) | Formlabs
• Preventing suction cups in PreForm | Formlabs

We organize manufacturer and community documentation; we have not measured these products ourselves. The manual for your exact model takes precedence over general guidance.