Problem with big flat plate

[Rosebud635 1]

Hello,

 

Overall my printer is working fine but I have trouble with long flat parts. As you can see on the picture everything is fine until, well, it is not.

The nozzle is clean and the problem only occurs with these parts.

Is there some trick?  

[geert_2 545]

That corner with underextrusion, is that the back left corner where the feeder is? If so, it could be because the filament is bent too much (especially if the spool is almost empty), causing way too much friction in the bowden tube and nozzle. In this case, try rotating the model 90 degrees. Or manually stretch a bit of filament. On my old UM2 - which is sensitive for this problem - I usually unwind 20cm of filament, wind it up in the opposite direction around a skater wheel (7cm diameter), unwind the next 20cm and wind in the opposite direction, etc... until I have done a few meters. Then I wind it up again on the spool, but now it is sitting very loose, with a bending radius of ca. 30...40 cm, about the same as the bowden tube. This reduces friction to almost nothing in the tube and print head. This stretching of filament takes only half a minute. Way less than typing this.  :)

 

If it is on all bigger models, it could also be that the little fan behind the nozzle does not work well, causing heat to transfer up into the filament, soften and compressing it, and prevent it from getting into the nozzle.

 

Might be other causes too?

[Rosebud635 1]

 

23 hours ago, geert_2 said:

That corner with underextrusion, is that the back left corner where the feeder is? If so, it could be because the filament is bent too much (especially if the spool is almost empty), causing way too much friction in the bowden tube and nozzle. In this case, try rotating the model 90 degrees. Or manually stretch a bit of filament. On my old UM2 - which is sensitive for this problem - I usually unwind 20cm of filament, wind it up in the opposite direction around a skater wheel (7cm diameter), unwind the next 20cm and wind in the opposite direction, etc... until I have done a few meters. Then I wind it up again on the spool, but now it is sitting very loose, with a bending radius of ca. 30...40 cm, about the same as the bowden tube. This reduces friction to almost nothing in the tube and print head. This stretching of filament takes only half a minute. Way less than typing this.  ?

 

If it is on all bigger models, it could also be that the little fan behind the nozzle does not work well, causing heat to transfer up into the filament, soften and compressing it, and prevent it from getting into the nozzle.

 

Might be other causes too?

Thank you so much for your answer.

I will try your 90° solution it seems very plausible.