Print will not come off the print bed: removing it safely
are explained briefly when you hover over or tap them.
Usually the problem is that a print does not stick. Sometimes it is exactly the other way round: the part sits so firmly that it will not come loose even after cooling. If you then pull with force or lever with a scraper, you risk scratches, torn-off pieces of the coating or a broken part.
Why does the print stick too well?
Material and plate do not go together
The most common reason is PETG on smooth PEI. PETG bonds very strongly to smooth PEI surfaces. In the worst case, the print rips pieces out of the coating when you release it. Some TPU types behave similarly. In its guide to preparing the plate, Prusa shows a steel sheet damaged by a PETG print and recommends a release layer for such combinations.
Z offset too low
If the nozzle is too close to the bed in the first layer, the material is literally pressed into the surface. On textured plates it then fills every depression and digs in. Typical sign: the underside is wafer-thin and glossy, and an elephant’s foot forms at the edges.
Bed too hot
A bed well above the manufacturer’s figure increases adhesion, especially with PETG. If the temperature is at the upper end, it is worth going down by 5 to 10 degrees.
Large, flat contact area
The larger the area, the stronger the adhesion overall. A large, flat plate made of PETG holds much more firmly than a small part made of the same material.
Releasing the print safely
1. Let it cool
Most prints come loose a little by themselves as they cool, because plastic and plate shrink by different amounts. Let the plate cool completely to room temperature. With large parts this can easily take half an hour. Patience is cheaper here than a new plate.
2. Bend the spring steel plate
With magnetic spring steel plates, take the plate off and bend it slightly, first in one direction, then in the other. Prusa recommends exactly this as the standard method, without a scraper. Important: only bend it slightly. A kink is permanent and the plate will no longer lie flat afterwards.
3. Carefully with the scraper
If bending is not enough, place a flat plastic scraper at a corner, as flat to the plate as possible. Do not lever, but slowly slide it under the part. Only use metal scrapers on smooth, uncoated glass plates; on PEI they easily leave scratches.
4. Water or isopropyl alcohol if needed
A few drops of water or isopropyl alcohol at the edge of the part creep into the gap and make release easier. If glue stick was used as a release agent, warm water dissolves the glue and the part comes off almost by itself.
Avoiding damage to the plate
- Release agent for critical combinations: For PETG on smooth PEI, apply a thin layer of glue stick. Here it does not act as an adhesion promoter but as a release layer. Bambu Lab advises glue on its smooth plates for all materials except PLA, so that the PEI layer does not tear out. Prusa stresses: a thin layer is enough.
- Clean the plate properly: Degrease the cold plate with isopropyl alcohol (at least 90 %). Wash off glue residue with warm water and washing-up liquid.
- Do not tear it off while warm: A part that is still warm has not yet pulled back from the plate and is often stuck the hardest.
- Tear-outs cannot be repaired: You can work around small spots by placing the parts elsewhere. If the surface is damaged over a large area, a new plate is due.
Which plate for which material?
The figures differ by manufacturer and coating. When in doubt, the material table of the plate manufacturer applies.
| Material | Smooth PEI | Textured PEI | Note |
|---|---|---|---|
| PLA | good | good | holds without a release agent |
| PETG | only with glue stick as a release layer | good | textured is the safe choice |
| TPU | with a release layer | usually good | can stick very firmly to smooth PEI |
| ABS, ASA | good, often with glue | good | adhesion depends heavily on the chamber temperature |
| PA, PC | with glue | with glue | glue stick improves adhesion here |
Textured PEI is the most straightforward choice for most everyday materials. The print usually comes off without help after cooling, and the underside gets a slightly rough texture. Smooth PEI gives a glossy underside, but takes more care with PETG and TPU.
The opposite problem, a print that comes loose during printing, is covered in First layer will not stick.
Quick checklist
- Plate fully cooled to room temperature?
- Bend the spring steel plate slightly, do not kink it.
- Use only a plastic scraper and hold it flat.
- PETG or TPU on smooth PEI? Next time use glue stick as a release layer or a textured plate.
- Check the Z offset if the first layer is very thin and glossy.
- Bed temperature at the upper end? Go down 5 to 10 degrees.
Continue with: PETG for the right temperatures and plates.