First Layer Issues
What Is It?
First layer issues reduce the chances of a successful print and are often the cause behind several failed 3D prints. Some of the significant and most common first layer problems are - prints not sticking to the bed surface, the first layer too rough, the nozzle not extruding filament or holes and lines in the bottom of your prints.
These problems can either affect the quality of your prints or cause them to fail, leading to loss of filament and printing times. Therefore, it's crucial to eliminate these issues and ensure a smooth and even initial layer.
Things to check
- Print Bed level
- Nozzle-Bed Distance
- Printing Speed
- Printing Temperature
- Cooling Settings
- Layer Height
- Print bed surface
How to Fix it?
Level the Print Bed
An incorrectly leveled print bed is the top reason behind a failed first layer. Leveling the print bed ensures that the nozzle and the bed surface are at an equal distance at all points on the print surface.
If the hot end is too close to the print bed, it will squish the filament on the surface. In contrast, if the nozzle's too far away, the filament will not stick to the bed leading to a failed print. Billie Ruben has created a helpful infographic poster using which you can understand the side effects of an incorrectly leveled bed.
If your printer has a manual bed leveling system, you can adjust the bed level by inserting a business card between the nozzle and the bed. You need to adjust the bed screws until the card slightly drags between the hot end and the bed, and repeat this procedure on all four corners of the print bed.
Alternatively, with automatic bed leveling, you'll need to adjust the z-offset setting of your 3D printer. This setting is available in the printer's configuration, or you can configure it within your slicer software.
You can refer to this first layer calibration guide by Michael from Teaching Tech to iron out your first layer. It goes into detail over both the methods and you can use the Gcode generator to create a test print for verifying your bed leveling.
Decrease Initial Layer Print Speed
A slow initial layer print speed will allow sufficient time for the filament to stick to the print bed properly. It ensures that your first layer's delicate outlines and intricate details (if any) are laid down slowly on the bed surface and stick well to it.
Usually, you can set the first layer print speed to be around 20% of the overall printing speed for your model. In terms of actual units, an ideal first-layer speed can be anywhere between 15 -25 mm/s. This range should give you a good balance between print quality and time and ensure that your first layer sticks well to the surface.
If the print peels off due to high printing speed, and it's left unattended for a while, the subsequent layers will form a spaghetti-like structure and ruin the printing process. You can Obico (formerly Spaghetti Detective) to automatically detect the failed print, and stop the printing. It will help you save on the precious filament material and save some printing time.
Increase First Layer Print Temperature
It would help if you kept the initial layer temperature 10-15 °C higher than the normal print temperature. It allows the filament to melt neatly, resulting in a smooth flow for the first layer. It also helps the filament to stick well to the print bed and form a strong bond with the printing surface.
Additionally, you can use a heated bed to create a warm ambient temperature, reducing the chances of warping or curling the filament on the first layer.
Shut off the Part Cooling Fan
The part cooling fan will induce a cool air stream onto the hot first layer. This temperature difference will cause the first layer to curl up from the edges leading to warping or filament not sticking to the bed.
Shutting off the cooling fan for the initial two layers will let these layers stick correctly to the print bed and increase the chances of your print's success. This setting is available in every slicer, and you can configure the layer numbers for which you need to shut off the cooling fan.
Prime the Nozzle
Priming the nozzle before the printing starts ensures there's sufficient filament in the hot end to lay down a smooth first layer. Otherwise, the initial points of your first layer might not have adequate material leading to an uneven or rough layer.
You can prime the nozzle by adding skirts or brims to your prints from the slicer settings or add a priming Gcode to start your print. Alternatively, you can manually push the filament out of the hot end to ensure adequate material before the print begins.