For 3D printer users, one of the most critical topics is bed leveling and first layer calibration. The foundation of a successful print depends on the first layer adhering correctly. In this guide, we will explain step-by-step how to manually and automatically adjust your 3D printer's bed, how to perform first layer calibration, and what to consider for different bed surfaces.
Manual Bed Leveling:
Manual bed leveling involves manually adjusting the distance between the bed and the nozzle using the screws on the four corners of the 3D printer's bed. An A4 paper is typically used for this process. In the paper method, an A4 paper is placed on the heated bed, and the nozzle is brought close to each corner one by one. A distance should be set where the paper can lightly rub between the nozzle and the bed. If the paper moves too easily, the nozzle is too far from the bed; if the paper doesn't move at all, the nozzle is too close to the bed. This process is repeated until all corners feel the same.
Automatic Bed Leveling (ABL):
Automatic Bed Leveling (ABL) allows you to automatically measure the curvature of the bed surface using a probe like BLTouch or CR-Touch and adjust the nozzle height accordingly during printing. ABL sensors create a 'bed mesh' by taking measurements at specific points on the bed. The printer uses this mesh to dynamically adjust the nozzle height while printing the first layer, thus eliminating problems caused by bed curvature. ABL sensors provide great convenience, especially for printers with large build areas or uneven beds.
Importance of First Layer Height:
The first layer height is critical for the print to adhere to the bed and for overall print quality. If the first layer is too high, the print may not stick to the bed, or gaps may form between layers. If the first layer is too low, the nozzle can scrape the bed, blocking filament flow, and resulting in a failed print.
Signs of Nozzle Too Close or Too Far:
- Nozzle Too Close: Filament is squashed and spread on the bed, layers don't stick to each other, and the nozzle's sound can be heard. It's also possible for the nozzle to leave scratches on the bed.
- Nozzle Too Far: Filament does not stick to the bed, hangs in the air, or trails as thin strings. Gaps form between layers, and the print is weak.
Z-Offset Adjustment:
Z-offset is a parameter used to precisely adjust the distance between the nozzle and the bed. When using automatic bed leveling sensors, the Z-offset value is adjusted to compensate for the difference between the distance measured by the sensor and the actual nozzle height. Correctly adjusting the Z-offset value ensures perfect first layer adhesion.
Mesh Bed Leveling:
Mesh bed leveling is a subset of automatic bed leveling and allows for a more detailed map of the bed surface. This method can compensate for more complex curvatures by taking measurements at more points on the bed. Mesh bed leveling is particularly useful for printers with large and uneven beds.
Tips for Different Bed Surfaces:
- Glass Bed: A glass bed provides a smooth and flat surface. It is recommended to use a heated bed and adhesive for good adhesion.
- PEI Bed: PEI (Polyetherimide) beds offer excellent adhesion and generally do not require adhesive. However, it is important to keep the PEI surface clean.
- Textured Bed: Textured beds give the bottom surface of the print a different texture and increase adhesion. For these types of beds, the first layer height may need to be set slightly higher.
This guide will help you correctly perform bed leveling and first layer calibration for your 3D printer. Remember that every printer and every filament is different, so it's important to use trial and error to achieve the best results and optimize settings according to your prints.