The first layer of a 3D print is the most important aspect of a 3D print that ensures a successful print. If your first layer loses adhesion then your part will turn into a mess of spaghetti filament.
In general most first layer issues can be resolved by leveling the 3D printers build plate. The first layer of a 3D printer can also be improved by fixing any temperature issues, treating the build plate, cleaning any debris from the nozzle, slowing down your 3D printer, and adding a raft or brim.
I have broken down all these common issues in further detail to help you resolve any first layer issues you may be having.
Level Your 3D Printer Bed.
The first and most important aspect of achieving a perfect first layer is leveling your 3D printer build plate. An unlevel build plate will cause the nozzle to be too far from the build plate in some areas and the nozzle to be too close to the build plate in others.
To level your 3D printer bed follow this guide on how to manually level a 3D printer bed.
If you are using an Ender 3 and are struggling to maintain a level bed you should replace the springs on your 3D printer bed. Here is an amazon link for upgraded springs as well as a full metal extruder.
Verify Your 3D Printer Z-Offset.
If your 3D printer’s nozzle is too far from the bed or too close to the bed it causes the material to extrude either too squished or too tall, as the graphic below shows.
If the nozzle is too close to the bed the material will be too compressed and will cause the first layer to extrude too wide. This wide over compressed layer will result in a ribbed like surface instead of a smooth even surface. This is illustrated by the red extrusion above.
If the nozzle is too far from the bed the material will be too tall and will cause the first layer to extrude too narrow. The narrow over extrusion will result in a stringy incomplete first surface instead of a smooth even surface. The tall extruded layer will also have compromised bed adhesion and will likely result in a failed print. This is illustrated by the yellow extrusion above.
For an optimal first layer you want the nozzle to be the correct distance from the bed. You should be able to run your finger over the extrusion without the extrusion loosing adhesion from the bed. As illustrated by the green extrusion above.
Check Your Extruder And Bed Temperatures.
If your extruder temperature is too low it will result in under extrusion as well as the material not adhering to the build plate properly. If you ever experience the material building up on your nozzle and not sticking to the build plate at all your nozzle is probably not hot enough.
Also verify that your filament is not coming out too liquid and flattening out. This might be a bed temperature issue or a nozzle temperature issue.
If the corner of your print is lifting your bed temperature is probably too low. Adding 5 degrees to your build plate could be the difference between a print adhering and a print failing.
Use A Surface Treatment On Your Build Plate.
Using a surface treatment on your 3D printer’s build plate is a great way to achieve better bet adhesion on your first layer. The best methods for achieving better bed adhesion are stick glue, blue painters tape, and hair spray.
Use a washable glue stick and apply a thin layer on your build plate in the areas that your 3D print is needing additional bed adhesion. You do not have to cover the entire build late with the stick glue.
It is better to use washable stick glue because it is much easier to remove when your print is complete and can be removed simply by running warm water on the plate and lightly scrubbing the glue off.
I also prefer to use the purple disappearing glue because it is easier to see where you have applied the glue. Here is a link to the stick glue that I use.
Blue Painters Tape.
Blue painters tape is another great bed adhesion technique especially for parts that have fine details on the first layer. To use blue painters tape just apply a single layer of blue tape to the build plate and offset your Z axis to compensate for the tape thickness.
Blue painters tape is typically .1mm thick.
You can pick up blue painters tape at virtually any hardware store or dollar store but if you are anything like me you order most things online. Here is a link to blue painters tape for quick access.
Hair spray is a pretty common adhesion technique among 3D printing hobbyists. Personally I prefer stick glue but some people swear by hairspray so I felt like I needed to mention it.
Just spray a thin layer of hairspray on your build surface to achieve a slight layer of tackiness that will help with adhesion.
To remove the hairspray simply wash your build plate with warm water.
Clean Your Nozzle.
Excess material around the nozzle can drop on to your 3D printer mid first layer and cause damage to your first layer.
If the excess material is a higher heat resistant material than your current print such as PETG printing at PLA temperature the material may stay hard on the nozzle and cause an issue throughout the entire print.
A clogged nozzle can also lead to a compromised first layer. If the tip is clogged with a forign material it will under extrude and will lead to an inconsistent first layer. You can clean the nozzle with a nozzle cleaning tool or a metal wire brush.
Slow Down 3D Printer Speed.
Slowing down the speed of the first layer will not only increase the quality of the first layer in most cases, it will also help you to troubleshoot issues such as bed leveling.
A slower first later will allow you time to adjust the bed live and achieve a perfectly level bed without having to stop your print.
Slowing down the print also helps the printer around tight corners as well as tight radii. If you are still having issues with bed adhesion you may need to use multiple of these strategies simultaneously with another of them.
Add A Raft Or Brim.
A raft or brim is a great way to achieve better bed adhesion as well as will ensure a perfect first layer by essentially creating another build plate on top of the existing build plate.
For a raft or a brim you will still need a relatively level bed to create the first layer. For more information about creating a raft or a brim check out this article.
Make Sure Your Nozzle Is Not Dragging.
If your machine’s rollers are loose or the frame is not square it may lead to your nozzle dragging across the print. The nozzle dragging is usually pretty obvious because you will either hear the nozzle scraping the surface or your printer will not be extruding at all.
If you are experiencing nozzle dragging check out this article on the Top 8 Reasons Your Nozzle Is Dragging.
There are many ways to ensure that you have a perfect first layer. If you are still unable to create a perfect first layer always go back and ensure that your bed is level and your machine is in good working condition.