The Perfect First Layer: A Step-by-Step Calibration Guide

## The Calibration Order Matters Always calibrate in this order — each step depends on the previous one being correct. ### 1. Heat the Bed First Run your bed to print temperature and wait 5 minutes. Never calibrate cold — the bed expands when heated and your cold calibration will be wrong. ### 2. Home All Axes Home X, Y, Z to reset position reference. Do this before every calibration session. ### 3. Level the Bed (4 corners + center) Use the manual mesh or paper test at: - Front-left corner - Front-right corner - Back-left corner - Back-right corner - Center The paper should slide with slight friction everywhere. If one corner is off by more than 0.3 mm versus center, re-level that corner. ### 4. Set Z-Offset Run a single-wall square test (40×40 mm, 1 layer, 0.2 mm height). Observe: | Line looks like | Adjustment | |----------------|-----------| | Round bead, not squished | Lower Z by 0.1 mm | | Slightly flat, shiny | Perfect ✓ | | Very flat, squished wide | Raise Z by 0.1 mm | | Lines merging together | Raise Z by 0.15–0.2 mm | ### 5. Calibrate Flow Rate (E-steps) Print a single-wall cube, measure wall thickness with calipers. Expected: 0.4 mm for a 0.4 mm nozzle. If measured 0.45 mm: reduce flow to 88% (0.4/0.45). If measured 0.38 mm: increase flow to 105% (0.4/0.38). ### 6. Run a First Layer Test Print Use a first-layer calibration pattern (available on Printables/Makerworld). The lines should be: - Evenly spaced - Slightly squished (not round, not over-squished) - Same width throughout - No gaps or overlaps ### 7. Save Your Settings After successful calibration, note your Z-offset value. If your printer loses it after power cycle, add it to your start G-code: ``` G29 ; Auto bed level M851 Z-X.XX ; Your Z-offset ```