With 3D printing being a complicated process with complex software and hardware involved, problems can present themselves in various forms, meaning that you may find yourself looking at lines of code one day and trying to scrape filament off the build plate the next.
Despite them causing frustration at times, dealing with issues throughout our 3D printing journey is half of the fun, as each issue we face improves our understanding and knowledge of the process.
In this article, we will be analyzing one of the most common issues in the 3D printing space, when filament, PETG in particular, does not stick to the bed as it should, essentially rendering the model you print unusable.
So, what should you do if your PETG filament isn’t sticking to the bed of your printer?
- Increase the temperature of the print bed
- Increase the temperature of the hotend
- Decrease the speed of the cooling fans
- Clean the print bed
- Level the print bed
- Add brims to the models you print
Next up, we will explain how to perform each of these solutions in greater detail and look at the different factors that can cause PETG to not stick to the bed, which will be helpful to choose the correct fix for your case.
PETG Not Sticking to Bed – What to Do?
As there are plenty of things that can cause PETG to not stick to the bed, there are also plenty of solutions you can apply.
Increase Print Bed Temperature
Increasing the print bed temperature is the first thing that comes to mind for issues related to PETG not sticking to the print bed.
In the scenario where you aren’t experiencing any other issues with your prints other than the filament not sticking to the bed, a low bed temperature is the most likely culprit.
We recommend increasing the bed temperature of your 3D printer to a value between 70 and 80 degrees Celsius to ensure that the bed is hot enough for the PETG to stick.
If the bed temperature is already between this range, do not increase it as doing so will present a different set of problems.
Increase Nozzle Temperature
The nozzle temperature not being high enough be the reason behind PETG not sticking to the bed. If the filament isn’t hot enough, it won’t melt as it should and won’t have the adhesive capabilities it needs to stick to the bed.
Alongside filament not sticking to the bed, a low nozzle temperature will also cause poor layer adhesion and issues related to under-extrusion, such as skipping and grinding.
While the optimal nozzle temperature can show differences between different PETG filaments, we recommend going for a nozzle temperature between 220 to 260 degrees Celsius.
On the other hand, if the manufacturer of the filament you’re using states the optimal temperature, we highly recommend using that value instead.
Decrease Cooling Fan Speed
Even though it’s not a factor that controls the temperature directly, fan speed plays a significant role in how hot the filament gets and how quickly it cools down.
Symptoms of a cooling fan speed that is too high are poor layer adhesion and warping on the models you are printing, alongside issues with filament sticking to the bed.
We recommend lowering your current fan speed in increments of 10 percent until you don’t have issues with PETG not sticking to the printer bed anymore.
As cooling fan speed also plays a vital role in the surface resolution of the models you print, it’s best to keep it as high as possible instead of directly setting it to a low value to combat adhesion issues.
Clean the Print Bed
A dirty print bed can easily cause PETG or any other filament type to not stick to the printer bed.
As a dirty print bed won’t present any other symptoms, it’s always a good idea to clean it frequently to rule out the possibility of a greasy print bed being the problem.
We recommend cleaning the print bed thoroughly with isopropyl alcohol and refraining from placing any objects on it to ensure that it stays clean.
Since even a simple action such as touching the print bed with oily fingers can ruin adhesion, a print bed that you regularly clean will make a significant difference.
Level the Print Bed
A print bed that isn’t level can also cause issues related to PETG sticking to the bed.
A bed that isn’t level comes with symptoms such as gaps, issues with the width and height of the model you’re printing, and the nozzle not extruding at all in some areas.
We recommend ensuring that the bed is level by using the instructions you can find in the documentation of the firmware you’re using.
A great way to ensure that your bed always stays level is to use a probe such as BLTouch, as it will automatically handle the process for you.
As a level bed is vital for the overall health of the printing process, it’s a good idea to check that everything is in order with a bubble level now and then.
Add Brims to the Model
If all else fails, adding brims to the model can come in quite handy to make PETG stick to the bed.
As adding a brim increases your model’s contact with the printer bed, it can quickly solve the bed adhesion issues you’re facing with PETG.
Since this is more of a band-aid fix rather than addressing the cause of the problem, we only recommend adding a brim if nothing else has worked for you.
Should You Print PETG on Glass?
Printing PETG on glass is tricky, with many members in the community having issues with either separating the model from the glass bed or getting the model to stick.
We recommend using a build surface such as PEI for printing PETG and refrain from printing PETG on glass whenever possible.
Considering how problematic printing PETG on glass can be, investing in a PEI build surface will easily save you a significant amount of time and effort.
As it’s possible to stick the PEI build surface on top of your pre-existing glass bed, you can remove it whenever you would like to use the glass bed instead.
What Temperature Should a Bed Be for PETG?
Using the correct bed temperature for printing PETG is extremely important.
While a too low temperature causes sticking issues, a too high temperature may make it impossible to separate the model from the bed.
We recommend using a bed temperature between 70 to 80 degrees Celsius for printing PETG as these figures allow the heated bed to be hot enough for PETG to stick but not hot enough to cause issues.
Since the exact value that works best can differ between printers, we highly recommend running experiments until you find the best number possible.
As PETG not sticking to the bed is a common issue, the 3D printing community has come up with plenty of solutions over time that hopefully will also work for you.
To quickly recap, here are the things you can try if PETG filament isn’t sticking to the print bed:
- Increase bed temperature
- Increase printing temperature
- Decrease cooling fan speed
- Ensure that the print bed is clean
- Ensure that the print bed is level
- Add brims to the models you print
We hope that you have found this guide to be helpful!