PETG behaves differently enough from PLA that copying your PLA workflow over usually ends in stringing, cobweb-like blobbing between small features, or prints that rip the PEI coating off the plate on removal. The A1's open frame — no enclosure, no chamber heating — changes what "correct" PETG settings look like compared to an X1C or P1S.
| Setting | A1 value | Why |
|---|---|---|
| Nozzle (main) | 235–240°C | Slightly cooler than enclosed-printer defaults (250–255°C) — the open frame loses heat faster, so less compensation is needed |
| Nozzle (first layer) | 245–250°C | A touch hotter for first-layer bonding |
| Bed | 70°C | PETG needs more bed heat than PLA for adhesion |
If you're getting popping sounds, hissing, or blistered surfaces, that's wet filament, not a temperature problem — PETG absorbs moisture readily. Dry it at 65°C for 4–6 hours before touching any other setting.
PLA wants aggressive cooling; PETG doesn't. Too much part-cooling fan on PETG causes layer delamination since it needs more retained heat to bond between layers than PLA does. Too little causes stringing and surface blobs — so this is a narrower window to hit correctly.
PETG is more viscous than PLA and needs more time to properly bond between layers. Running it at PLA-speed settings is one of the most common causes of stringing, zits, and inconsistent extrusion on the A1. Drop outer wall / perimeter speed by at least 20mm/s from whatever you run for PLA as a first move if you're seeing rough or inconsistent outer walls.
Work through it in this order: dry the filament first, then verify temperature with a tower test, then check the nozzle isn't partially clogged. The same troubleshooting order applies to PETG as PLA — see the full stringing fix guide for the details on each step.