This type of defect is a print failure unique to stereolithography (SLA). If a piece of the print sticks to the bottom of the resin tank, that piece partially blocks the laser from reaching the next layer of the print. The piece stuck to the tank expands with each additional cured layer and prevents other features from forming.

• A void within a print that expands outwards from the earliest layer to the most recent layer, usually with sharp edges and rough surfaces like a crater
• A layer of cured resin on the bottom of the resin tank

Any of the following factors, or a combination of them, can cause prints to have undeveloped features:

• Debris or damage in resin tanks
• Clouding in Form 2 standard resin tanks
• Model orientation, layout, or support issues
• Contaminated optical surfaces

成功的故障排除可以识别症状并系统地缩小问题的根源。按照下方故障排查步骤检查打印缺陷的潜在原因，并按照可能性从高到低的顺序进行排除。

Step 1: Check the model in PreForm

Review the model in PreForm for orientation, layout, or support issues:

1. Inspect the printed part to determine where the undeveloped feature started. In PreForm, look for the area on the part where the outward-expanding explosion is closest to the build platform.
2. Examine individual layers of the model with the vertical Slicer tool on the right side of PreForm. Pay close attention to the following areas as the possible origin for the undeveloped feature:
   • Look for any areas on the model highlighted in red. These highlighted areas indicate printability concerns and may need additional support.
   • Even if there is no red shading, consider adding extra supports to any areas that failed during printing.
   • In particular, look for local minima and islands that need additional support.

Step 2: Check the resin tank

Any damage or debris in or on the resin tank can block the laser at that location, preventing the resin directly above it from curing. Inspect the inside and underside of the tank for dirt, dust, and/or fingerprints. The bottom of the tank must be clean for the best print results.

Step 3: Check the optical surfaces

Any contamination, dust, or debris on the printer’s optical surfaces can cause the laser light to diffuse or weaken, resulting in a print failure. Contamination is most likely to occur on an exposed optical surface in the printer.

The optical surface most likely to be contaminated is the release texture, which sits atop the Light Processing Unit (LPU) and Backlight Unit.

1. Inspect the release texture for contamination.
2. Follow the instructions in Cleaning the release texture (Form 4 generation). If the debris or contaminants are difficult to remove, contact Formlabs Support or your authorized reseller.

The optical surface most likely to be contaminated is the glass optical window, which sits atop the Light Processing Unit (LPU).

1. Tap the wrench icon to access the Settings screen, then tap Maintenance > Motor Moves. The Motor Moves screen appears. Tap and hold Left (<) to move the LPU housing to the middle of the printer cavity. Other controls on this screen fully sweep the LPU housing across the printer cavity and control the build platform carriage.
2. When prompted by the touchscreen, disconnect the power cable before continuing with maintenance.
3. Inspect the optical window for contamination.
4. Follow the instructions for cleaning the glass optical window.
   • Form 3/Form 3B
   • Form 3L/Form 3BL
5. If streaks are difficult to remove, contact Formlabs Support or your authorized reseller.

The optical surface most likely to be contaminated is the glass optical window beneath the resin tank that protects internal components from contamination.

1. Inspect the optical window on the Form 2 or for contamination.
2. Follow the instructions in Cleaning the glass optical window (Form 2). If streaks are difficult to remove, contact Formlabs Support or your authorized reseller.

If the troubleshooting steps above do not resolve the print failure, contact Formlabs Support or your authorized reseller.

To help us provide the fastest and most effective response to your issue, please follow these steps:

1. Upload diagnostic logs
   • On a Form 2
   • On a Form 3/Form 3B
   • On a Form 3L/Form 3BL
   • On a Form 4/Form 4B
2. Serial name of the printer
   • The serial name is on the back panel of the printer in the format AdjectiveAnimal.
   • On a Form 2: Tap the printer icon on the home screen. The Your Printer screen appears.
   • On a Formlabs LFS printer (Form 3 or later): Tap the printer icon on the Home screen.
3. Troubleshooting steps attempted
   • Example: “I reoriented the model in PreForm. I inspected the resin tank and did not notice any damage, clouding, or debris.”
4. Resin formulation and lot number
   • The lot number is inside the skirt of the resin cartridge.
5. Layer thickness
   • On a Form 2: Tap the queue icon on the home screen. The Jobs screen appears.
   • On a Form 3/Form 3B or Form 3L/Form 3BL: Tap Queue on the Home screen. The Queue screen appears.
   • On a Form 4 generation printer: Tap the queue icon on the printer’s touchscreen. The Jobs screen appears.
6. Relevant FORM files
   • If available, attach FORM files of the model to the support request.
7. Previous attempts to print the part and any successful prints
   • Example: “I printed the file part2.form three times previously. The first and second were successful. The third one failed.”