Filament runs out of nozzle when preheating
Hello,
I have a question regarding the preheating. Whenever I want to print something new and the printer preheats, filament oozes out of the nozzle. I have attached an image, but normally it is even much more that oozes out. Sometimes so much it touches the bed and it gets too heavy and falls off. I have read different threads about it but with no real answer. Some say its normal, some seem to have no issue. Acutally I think this can't be normal. This issue is also not allowing me to do any time based printings as I always need to clean that filament right before the print starts.
I also read that wet filament can cause that, but I use dry boxes with around 30% humidity to keep the filament dry.
I have also changed the nozzle already, same issue.
Any help would be really appreciated. Thanks!
The longer the filament has sat out, the more this will happen.
Steam. Pushes. Hot. Filament. Out.
Use it up before it gets too wet to use.
Really normal?
As I have said the filament is brand new and I store it in dry boxes with 30% humidity. The room itself has 50% humidity. It happens with PLA and PETG. Everytime.
The linked thread bascially tells it is normal behavior and needs to be fixed by code. I can't believe that, how on earth would you do time based printing then? Not possible as you always need to remove the oozed filament before the print starts.
Look at the mini-preheat sequence
The oozing can be prevented by changing the sequence and timing of the nozzle heat. Instead of heating at the start of the bed leveling sequence, delay it to the end, that kind of thing. The pre-heat sequence for the Mini is a good example of this to contrast with the MK3S.* family.
RE: Filament runs out of nozzle when preheating
Google brought me to this post. I am having exactly the same problem when I print PETG. My print temperature is 230 degrees on MK3+. The filament oozes out at preheating. The filament is dry and new. I also replacement the nozzle, heat block, thermistor. Nothing improves. I am pretty sure this is not caused by hardware. I am hoping Prusa is listening to the feedback and fix it in next firmware release.
RE: Filament runs out of nozzle when preheating
Google brought me to this post. I am having exactly the same problem when I print PETG. My print temperature is 230 degrees on MK3+. The filament oozes out at preheating. The filament is dry and new. I also replacement the nozzle, heat block, thermistor. Nothing improves. I am pretty sure this is not caused by hardware. I am hoping Prusa is listening to the feedback and fix it in next firmware release.
It's not the firmware, either. The sequence of events at the start of a print is controlled in the start g-code generated in your slicer. You can change your start g-code in the slicer to alter this sequence and largely eliminate the problem you are experiencing:
https://projects.ttlexceeded.com/3dprinting_prusaslicer_start_gcode_mk3.html