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When printing large objects, you can sometimes run into an issue with the corners of the object being lifted from the bed – mostly when printing with high-temperature materials such as PC Blend, ASA or ABS. It’s usually a result of a sudden temperature difference between the melting temperature of the nozzle and the ambient temperature. When this happens, the plastic will shrink and warp. Our goal is to minimize the thermal shock the printed part receives so it doesn't warp as much. Less warping also means less residual tension and a stronger part.
Adding a layer of glue stick, applied thinly on the steel sheet when cold, can both help adhesion and act as a separation layer, protecting the sheet from wear and tear.
Each material requires a different technique to prevent the lifting of the object. Different geometries may also need different approaches. Be sure to check our extensive material table for more information.
- Use PrusaSlicer profiles – Make sure you are starting off by using corresponding default profiles in PrusaSlicer. You may save yourself a lot of hassle with figuring out the ideal settings yourself. Profiles are already refined for each material.
- Keep the surface free of grease – Before starting any of your prints, simply wipe the print surface clean with IPA 90%+. A complete guide on how to prepare the print surface can be found at First layer issues.
- Lower the Live Adjust Z slightly to increase bed adhesion. But not too much. Do not over-squish the first layer. Be aware the bed adhesion might be too high with PETG or PC and might result in a damaged PEI surface.
- Print cooling. Some materials such as PLA or PETG need a lot of cooling. If corners of your print are lifting up, check if the print fan is enabled, try increasing the print fan speed. Check if the print fan actually works and the fan shroud isn´t obstructed or molten.
If steep overhangs and small parts of your print are warping, you may try enabling the print fan at low speeds (10-20%) even for materials that do not require a lot of print-cooling such as ABS or PC-Blend. This may help for example if you have a printer in an enclosure or if the problematic part is drowned in between supports that are retaining heat. Be aware that too much print-fan speed may warp and lift up the whole object and may decrease layer-to-layer adhesion. Our goal is to cool the part neither too fast nor too slow.
If you experience lower layer-to-layer adhesion or even print cracking after raising the print-fan speed, try increasing the nozzle temperature to restore the bonding of the individual layers together properly.
- Ambient temperature – For high-temperature filaments, try to maintain a stable ambient temperature. An open window or an AC unit nearby the printer will increase the occurrence of warps. High-temperature materials generally require higher ambient temperature not to warp during printing. If you print with these materials most of the time, you should consider having the printer in an enclosure. Printing PLA or PETG in an enclosure might not be a good idea. These materials need a lot of print cooling, which is harder to achieve with a higher ambient temperature. It is possible to either purchase an enclosure in our e-shop. You can purchase the Original Prusa Enclosure in our e-shop. It is also possible to make your own enclosure.
- Use a skirt and try to print more objects at once. For high-temperature materials such as PC-Blend, ASA, or ABS, try using a printed skirt (draft shield) to retain heat in and around the printed object. Printing more objects at once may also help with retaining heat. Try to orient the problematic parts of the objects towards the center of the heatbed.
- Decrease the print speed. This may help a lot with high-warping materials. Although Prusament PC-Blend is low-warping compared to other PC-Blend filaments, decreasing the print speed will help your part as a whole to settle down, melt individual layers together properly and warp less. It also increases the layer-to-layer adhesion and part strength.
- Use the brim – A brim is a good way how to increase the adhesion to the print surface.
If the brim isn't enough, try adding a small geometry (like a tiny cylinder) specifically to the culprit area. The object should only be a few layers tall so it is also easy to remove.