Nozzle scratched the plate during push

Separate symptom from “parts won’t detach”. Here your part might have released, or it didn’t, but the real damage is that the toolhead scraped across the plate during push, leaving a visible gouge. This is a z-axis skip, and it has a specific fix plus some aftercare.

What’s happening mechanically (Stage 1)

Stage 1 uses the printer’s own z-axis motor to drive the plate up against the bender bar for the flex. When the part is stuck too strongly to the plate, the z-motor skips steps under load. The printer still thinks the plate is at the bent position, so the subsequent push sweep happens with the plate several millimetres higher than expected, and the nozzle drags across the plate surface.

It’s a compounding failure: a single stuck part can bend the nozzle tip, which then scores the plate on every subsequent loop, which creates more gouges. Stopping at the first sign is important.

First, assess the damage

Power off the printer. Don’t try to continue “just one more”.
Inspect the nozzle. Look at it side-on. A healthy nozzle is a clean cone; a scraped nozzle has a burr or visible hook at the tip.
Inspect the plate. One or two shallow scratches: keep using it, but with the fix below. Deep gouges, or the pattern crosses your first-layer zones: replace the plate.

Fix the root cause — reduce adhesion

If the part released cleanly, the z-axis wouldn’t skip. Apply the full parts-won’t-detach fix stack before running more loops:

Raise z-offset to +0.02 or +0.04 mm
Lower the cooldown threshold by 4 to 6 °C
Switch to a worn-in textured PEI plate (not Frostbite, SuperTack, or Cryogrip, see choosing a build plate)
If your room is warm, consider the fan upgrade or an external cooling fan

Second: raise the push height

The FarmLoop app released an update in early 2026 that exposes a manual push-height slider under Detachment Tuning. Default is now 5 mm above the part; older builds used 2 mm, which was too tight.

Update to the latest app version if you’re seeing scrapes
Keep push height at the default 5 mm unless you have low-profile parts (see low-profile parts for guidance on reducing it safely)
If you’re on an older app and can’t update right now, open the FL_S1_ / FL_S2_ 3MF with 7-Zip, edit the .gcode under Metadata/, and raise the Z values in the push block by about 3 mm

When this keeps happening: upgrade to Stage 2

Stage 2 replaces the passive z-axis bend with an active linear actuator. The printer’s z-axis stays locked during the bend, so a skip is mechanically impossible. If your parts regularly push the z-axis into skip territory (large flat footprints, strong filaments like ABS or PETG), Stage 2 is the architectural fix rather than a bigger safety margin.

See compatibility for which Stage 2 kit fits your printer.

Recovery checklist before the next print

Nozzle replaced if it’s bent
Plate replaced if it’s badly gouged, otherwise cleaned with IPA
Adhesion fixes applied (z-offset, cooldown threshold, plate type)
Push height at 5 mm or later
Run a single-loop test print before any queue, do not jump back to overnight runs

When to contact support

If you’re on the latest app version, push height is at least 5 mm, you’ve applied the adhesion fixes, and the plate is still gouging on a fresh plate, send us:

The FL_S1_ / FL_S2_ 3MF file you were running
A photo of the gouge pattern
Your printer model and FarmLoop firmware version

Email contact@3d-farmers.com.

Parts won’t detach, the root-cause adhesion fixes
Choosing a build plate, avoid plates that make skips inevitable
Low-profile parts, how to reduce push height safely for short parts