E
fep_tension_alert
Moderate
Elegoo · Resin (SLA/MSLA) 3D Printers
FEP Film Tension Outside Acceptable Range
Quick Answer
Error code FEP_TENSION_ALERT on your Elegoo Resin (SLA/MSLA) 3D Printers means: FEP Film Tension Outside Acceptable Range. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. FEP film has stretched after many prints and is no longer at the correct tension
  2. FEP film was installed with incorrect tension during replacement
  3. FEP film has a small puncture or tear allowing resin to leak underneath
  4. Resin vat frame screws are not evenly tightened causing uneven FEP tension
How to Fix It
1
Visually inspect the FEP film for punctures, cloudiness, or visible deformation
2
Tap the FEP film gently with a finger and listen to the pitch; a properly tensioned FEP should sound like a drum, not a loose membrane
3
If the FEP is stretched or damaged, replace it with a new FEP sheet
4
When replacing FEP, use a tension gauge or the water-pour method to achieve proper tension (refer to Elegoo FEP replacement guide)
5
Tighten the resin vat frame screws evenly in a cross pattern to distribute tension uniformly
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Replacement FEP film (model-specific dimensions, 0.15mm standard thickness)
FEP replacement tool kit with clamp frame
Allen wrenches for vat frame screws
Related Error Codes
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