No way to stick PETG on buildplate

Question

I did my homework reading similar questions, like this, this and this. Here a video that shows the issue:

The filament is PETG from JAYO and the printer is a Dremel 3D45. As you can see, the filament does not stick on the buildplate. The manufacturer suggests to use 220-250 °C for the nozzle and 70-80 °C for the bed. Here what I tried so far:

• add purple glue from Dremel
• bed temperature from 70 to 80 °C
• nozzle temperature from 235 to 250 °C (below 230 °C it does not come out from the nozzle at all)
• print speed from 50 to 70 mm/s
• nozzle gap from 0.0 to 0.4 mm (in step of 0.1 mm). The video was taken with the maximum gap. When the gap is lower, almost all the filament sticks to the nozzle
• fan speed from 0 % to 50 %
• the filament is inside a filament dryer
• clean up the nozzle
• before each print I level and calibrate the buildplate

Honestly I don't know what to do further. From your experience what should I do to avoid what you see in the video?

Answer 1

Your nozzle is very much too high to properly print just about any filament. If the filament sticks to the nozzle after it is positioned closer to the bed, you have two problems. The first is the initial layer position, sometimes called z-offset. The second is bed adhesion.

While the bed is cool, clean it carefully using the appropriate substance for your bed. I'm not familiar with that specific printer, but a glass bed can be cleaned by just about anything, while PEI beds should not have acetone as the cleaning substance. IPA or Denatured Alcohol is pretty safe.

Once you can get a clean bed and good adhesion, bring the nozzle back to an appropriate height. 0.4 mm is the most common nozzle diameter (perhaps until lately) and will provide near zero adhesion. 0.15 is the value I use for my printer, but each printer will be different.

You don't want ropy stringy build lines, nor do you want a nozzle that flattens the filament into something you can't remove when cool. I've had too-low nozzle height in which the filament was nearly transparent and was nearly impossible to remove.

Answer 2

With one brand of PETG I used 110 degrees on the build plate and 240 for the nozzle. Couldn't get a decent first layer before that.

Answer 3

I agree with fred_dot_u, you are too far away from the bed. If you can't get it after that, I would suggest using Bed Weld by Layerneer.