I switched out my 0.4 mm Ultimaker 2+ Nozzle the other day for the 0.25 mm and started using a ColorFabb Copperfill 2.85 mm filament. I am having some issues with it clogging and sticking to the bed for larger prints:
Current settings are:
- Extruder Temp: 230°C
- Flow Rate: 110% (increased it from 108% get more consistent output)
- Bed Temperature: 70°C
I thought it might be a calibration issue since I could see it skipping certain sections and slowly collecting excess material on the outer nozzle, so I recalibrated the bed but I still ended up with a blocked nozzle after about two hours of running. Not too sure if there are other settings I need to take care of. Any suggestions would be great!
It looks like a problem with feeding filament. It could be good to know if you did try such big printouts before but even if - from your picture it looks like on far end there is too less filament but on near end it's too much of it (because of 110%). And near the big circle it looks better even on far end. And there are "waves" close to big circle.
How is that possible?
Assuming that your extruder works well it might be caused by bending bowden tube. If your filament is not slick enough - in some settings (positions/arrangements) of bowden it might create enough friction so it doesn't flow with proper rate. It might be also caused if your bowden tube was bent too much (broken).
To be sure please try to print 4 smaller (5 cm in diam) circles on bed's corners and the one in the center. Just one layer of course.
How to fix the issue?
In my opinion you could try to slow down whole printout. Try to print such big circle with 30% of regular speed. I'm pretty sure you'll get proper results.
Try to check if filament goes smoothly thought the tube. Check if it has proper inner diameter. You can try to clean up a tube inside if it's not perfect clean or change a tube to new one. I know it was probably ok for recent filaments but maybe this one is more "demanding" ;)