PETG is my number one favorite 3D printing filament material. PETG and ABS have a lot in common, but printing PETG can be as easy as printing PLA. Keep in mind, though, that PETG has more tendency to not stick to the bed.
PETG does not stick to the bed due to one of the following reasons:
- The first layer is not sticky enough due to incorrect bed temperature or because the surface is not clean (oil, dust, etc.)
- The hot filament is too squished to the bed, so it rolls back and sticks to the nozzle.
- The hot filament pulls the first layer to itself, due to incorrect retraction and feed settings.
- The first layers cool down too fast and start to warp on the bed.
Below you can read our step-by-step guide, which will help you make the first layers of PETG stick to the bed. The steps are sorted from the most probable solutions to less common ones.
Increase the nozzle or bed temperature
It is recommended to set the nozzle temperature in a range between 230 to 250o C. However, A hotter filament can stick better to the bed surface. So you can try increasing it. For the first try, set your nozzle temperature around 250o C. It is highly recommended to use a heated bed and put the bed temperature around 75o C or higher.
The main idea here is to put the hot filament on a hot surface to create stronger bonds with the hot surface. You can calibrate and decrease the temperatures after your first successful print.
If your printer doesn’t come with a heated bed, you can use blue tape with a thin layer of glue on top of it.
Double-check your printing settings
PETG filament’s setup is similar to the settings used for PLA. However, there are a few differences that you need to be aware of. PETG doesn’t like to cool down too fast, so turn off the first layers’ cooling fans. After that, you can use around 30% of the cooling fan’s power.
Lowering the printing speed can increase the final product’s quality and help with the first layer adhesion. You can set the printing speed around 10 to 15 mm/s initially and increase it after the first successful results.
Raising the feed rate and z offset can decrease the hot filament’s tension at the nozzle’s tip and the surface layer; Start with 0.2mm for the z offset and 1.1 for the feed rate.
Clean the printing surface
Cleaning the bed may be the best solution if you have done successful prints with PETG before. It is a good idea to clean the surface regularly with Isopropyl Alcohol.
Alcohol is not an excellent choice when it comes to cleaning oil from surfaces, though. The best option here is to disconnect the top cover from the printer and then wash it with hot water and soap.
Place the plate in hot water for one minute, then rub some soap, and finish with hot water until the soap disappears. After cleaning the surface, it’s time to put it back and level the bed again.
Level your 3D printer’s bed
I can’t emphasize enough how important bed leveling is. Not only will it solve the sticking problem, but it also increases your printing quality in various aspects. So, make sure your bed is leveled before working with your printer.
To do this, put the nozzle’s tip near one of the corners of the bed, and check its distance with a piece of paper. Rise the corner until you fill a friction force between the paper and the nozzle. Do this process for the other corners too. Then repeat it for another round. (So that every corner is checked twice) Don’t set the distance too short. It may squish the first layers and ruin your print.
Make sure the bed’s surface is even
Suppose the first layer only separates in a particular region, and mesh alignment does not help. In that case, it is probably due to an uneven surface. To get a flat print surface, you can put a piece of paper under the uneven area.
However, it’s better to perform the firmware Bed Level Correction or use an automatic bed leveler like a BLtouch sensor.
Add a brim
A brim is a layer of filament that extends along the part from all of the print edges. It helps improve first layer adhesion and prevents the print from warping. You can activate it from your slicer software.
Above, we discussed some of the most common solutions for when PETG Does not stick to the bed. However, the ‘best’ answer varies from one case to another. Feel free to comment below if one of our solutions helped you or found a new method that can help others.