On Formlabs SLA printers, the build platform lifts away from the resin tank after each layer prints. If the most recent layer adheres too strongly to the resin tank, it can damage your parts, resin tank, or printer.

On Form 4 and Form 4L generation printers in particular, the texture on the top surface of the Light Processing Unit (LPU) allows air to flow between the LPU and the resin tank, helping the build platform release from the tank. If that release texture is worn or faulty, or there is an issue with the resin tank, the build platform will be unable to separate from the resin tank properly. When the printer tries to move the build platform at the end of a layer, it will pull the resin tank up with it, flexing it against the resin tank latches. The build platform may be suddenly pulled down or released from the resin tank, usually accompanied by a loud motor noise, and the printer will abort the print.

• Build platform and most recently-printed layer do not separate from the resin tank properly
• Build platform pulls up on resin tank and resin tank latches before suddenly jerking up or down

• Faulty resin tank
• Worn or faulty Light Processing Unit release texture

1. Try again with another resin tank, if one is available.
2. Replace your printer’s LPU. If your printer and LPU are still covered by their warranty, contact Formlabs Support or your authorized reseller.
• Form 4 generation
• Form 4 LPU
• Replacing the Form 4 Light Processing Unit
• Form 4L generation
• Form 4L LPU
• Replacing the Form 4L Light Processing Unit