A volume explosion describes a print failure in which a void of missing material forms within a print and widens as the print builds away from the build platform. These voids can look like a crater and frequently exhibit sharp edges and rough surfaces.
A volume explosion is a print failure unique to stereolithography (SLA). SLA 3D printing uses a laser to cure photoreactive resin layer by layer. If a piece of the print sticks to the PDMS (silicone) layer on 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 to create the explosive effect for which this print failure is named.
For prints created on Formlabs printers, a volume explosion results in the following visual symptoms:
- A void within a print that expands outwards from the earliest layer to the latest layer. It will usually exhibit sharp edges and rough surfaces and may look 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 volume explosion in prints:
- Debris/clouding/damage in resin tank
- Model orientation, layout, and/or support issues
- Contaminated optical surfaces
Successful troubleshooting first requires identifying the root cause. Follow the troubleshooting steps below to isolate and resolve the print failure. The steps check for possible causes, moving from the most likely cause to the least likely cause of the print failure.
Step 1: Check the resin tank
Any debris, clouding, and/or damage in the resin tank can cause the laser light to diffuse, limiting the printer’s ability to fully cure the resin.
- Inspect the resin inside the resin tank for debris using a Form Finish Kit scraper and a fine-toothed comb. Remove any debris and cured resin in the tank using the scraper and the fine-toothed comb, or filter the resin.
- Inspect the PDMS (silicone) layer of the resin tank for clouding. Excessive clouding means the resin tank needs to be replaced with a new tank.
- Inspect the acrylic tank window on the underside of the resin tank for dirt, dust, and/or fingerprints. The clear tank window must be perfectly transparent for the best print results. To clean the tank window, only use Formlabs recommended steps and supplies.
TIP:Keep resin tanks clean and well-maintained between prints for reliable and successful printing.
Step 2: Check the model in PreForm
Use the tools available in PreForm to review the model for any orientation, layout, and/or support issues.
- Inspect the printed part to determine where the volume explosion initiated. In PreForm, look for the area on the part where the outward-expanding explosion is closest to the build platform. Note this area for the next step.
- Use the vertical Slicer bar on the right side of the PreForm window to examine the model. Pay close attention to areas noted in the previous step as the possible origin for the volume explosion on the printed model.
- Look for any red-highlighted areas on the model. These highlighted areas indicate Printability concerns and may need additional supports.
- Use the Slicer Bar to scroll through each layer of the print. Even if there are no visible red areas, consider adding extra supports to any areas that are failing.
- In particular, look for any local minima and islands requiring additional support. Watch “Chapter 6: Local Minima and Islands” in the video "Supporting Your Model in PreForm" for an in-depth walkthrough on identifying local minima and islands as well as adding custom supports manually in PreForm.
Step 3: Check 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.
On the Form 2, the primary exposed optical surface is the glass optical window, which sits below the resin tank and protects the mirrors from external contamination. Visit the interactive 3D Form 2 Glossary to learn more about the optical window and its location in the printer. On the Form 1+, the primary exposed optical surface is the large mirror, which sits below the resin tank.
- In the case of contamination, clean the contaminated surfaces using Formlabs instructions. Whether cleaning a Form 2 or a Form 1+, be sure to follow the instructions carefully because cleaning optical surfaces is a delicate process.
WARNING:Follow the optical surface cleaning guides exactly. Failure to follow instructions could result in returning the printer to Formlabs for repair.
Contacting Formlabs Support
If attempting the troubleshooting steps above does not resolve the print failure, feel free to contact Formlabs Support! Please provide as much of the following information as possible when submitting a support request:
- Describe the troubleshooting steps attempted so far. (Example: “I re-oriented the model in PreForm. I also inspected the resin tank and did not notice any damage, clouding, or debris.”)
- A photo of the location where the volume explosion occurred in the print.
- Resin type used. (Example: Resin Type: White v2, Grey v3, etc.)
- Layer Thickness of the print. (Example: 0.100 mm, 0.05 mm, or 0.025 mm.)
- Relevant .form files of the model. If available, attach .form files of the model to the support request.
- Number of previous attempts printing the part and any instances of successful prints. (Example: “I printed the file part2.form three times previously. The first and second were successful. The third one failed.”)