When a print will not stay on the bed, changing ten slicer settings at once usually makes the problem harder to understand. Work from the most common physical causes toward model-specific changes.
Start With The Failure Pattern
Identify what is actually happening:
- Nothing sticks anywhere: suspect contamination, the wrong plate profile or a nozzle that is too high.
- One side sticks and the other does not: suspect levelling, plate seating, debris beneath the plate or a mechanically uneven surface.
- The first layer starts well but corners lift later: suspect cooling, drafts, shrinkage or too little contact area.
- The nozzle scrapes or extrusion stops: the nozzle may be too close; do not keep lowering it.
- The part sticks far too strongly: check material and plate compatibility before printing again.
That distinction prevents an adhesion problem from being mistaken for a blocked nozzle or a model-design issue.
Step One: Clean The Plate Properly
Let the plate cool, remove it and handle it by the edges. Follow the plate manufacturer's instructions. For many PEI spring-steel sheets, warm water with plain dish soap is effective against skin oils. Rinse away all soap and dry the surface with a clean lint-free cloth.
Do not immediately cover a dirty surface with glue. Glue can be an adhesion aid, but on some material and plate combinations it acts as a release layer to prevent excessive bonding. It cannot reliably compensate for grease.
Step Two: Confirm The Correct Profiles
In the slicer, verify:
- Printer model and nozzle diameter.
- Filament type and brand profile where available.
- Build plate type.
- Nozzle and bed temperatures.
A textured plate, smooth PEI sheet and specialist cool plate can require different temperatures or calibration. Bambu Lab's plate documentation, for example, specifies different compatible materials and operating requirements across its plate range.
Step Three: Read The First-Layer Shape
Print a simple first-layer test or a broad single-layer square.
If individual lines look round with visible gaps, the nozzle is probably too far away. If the surface looks translucent, heavily ridged or torn, the nozzle is probably too close. The target is a continuous surface made from slightly flattened lines that touch without being ploughed by the nozzle.
Use the printer's documented first-layer or Z-offset procedure. Make small changes and judge the printed result rather than copying a value from another machine.
Prusa specifically cautions against lowering the nozzle excessively to compensate for poor adhesion: too little clearance can obstruct flow, cause vibration and damage the sheet.
Step Four: Re-Level And Inspect The Hardware
Run the printer's bed-levelling routine. Before doing so:
- Check that the plate is not sitting on a scrap of filament.
- Inspect the nozzle for a blob that could affect probing.
- Confirm the hotend, nozzle and bed do not wobble.
- Check that gantries and lead screws move normally.
Automatic bed levelling measures the surface, but it cannot fix a loose nozzle, badly seated plate or major mechanical fault.
Step Five: Reduce First-Layer Difficulty
If calibration is correct but a difficult model still lifts:
- Slow the first layer using a manufacturer-supported profile.
- Use the recommended bed temperature for that filament and plate.
- Increase the first-layer line width only within sensible profile limits.
- Add a brim to increase the model's contact area.
- Reorient the model to put a broader, flatter face on the bed.
- Shield ABS, ASA and other warp-prone materials from drafts, normally with an appropriate enclosure.
A brim helps with a small footprint or sharp corners. A raft is a more aggressive option and usually should not be the first response.
Step Six: Match The Material To The Surface
Different materials behave differently. PLA is usually forgiving. PETG can bond very strongly to some smooth surfaces, while ABS and ASA shrink more as they cool and generally benefit from stable enclosure temperatures.
Never assume that stronger adhesion is always better. Check the plate maker's compatibility table and use a release layer where instructed. Pulling an over-bonded PETG print from the wrong surface can remove part of the coating.
A Reliable Troubleshooting Order
Use this order and retest after each step:
- Clean the plate.
- Confirm the plate and filament profiles.
- Inspect the first-layer height.
- Run levelling and check plate seating.
- Confirm temperatures and first-layer speed.
- Add a brim or change orientation.
- Control drafts and enclosure conditions.
If the same area fails after all of these checks, inspect the bed and motion system rather than continuing to tune the slicer.