Filament imperfection on my print

[jojomw3 0]

Hello I'm new to 3d printing, I've just done my biggest print in months but there are small imperfection problems. 
 

On the sides of the mask it is sometimes smooth and sometimes the lines are weird, or under the eye it doesn't take well. 

 

Is this due to my printer being out of adjustment?

 

if you have any advice on this, I'd love to hear from you. 

[GregValiant 1,410]

What printer?  There are extrusion problems, but there is also color banding in the filament (the sort of beige areas).  I see a couple of black flecks in there as well.

[jojomw3 0]

14 hours ago, GregValiant said:

What printer?  There are extrusion problems, but there is also color banding in the filament (the sort of beige areas).  I see a couple of black flecks in there as well.

I have an anycubic kobra plus, So if it's an extrusion problem, it's coming from my printer?

[gr5 2,267]

Those dotted lines are underextrusion.  It's classic, obvious underextrusion.  When you've seen it a few thousand times you recognize it instantly.

 

What's the cause?  Could be hundreds of possibilities.  Google "anycubic kobra plus underextrusion" and try all the suggested things.  People will tell you "it's definitely A with solution B" and the odds they are correct are around 20% as there are so damn many causes of underextrusion and every printer type has different issues.

 

Oh hell.  I'll give you one possible cause.  There's about a 5% (1 in 20) chance it's a dirty Z screw and if so the symptom will have overextruded layers nearby the underextruded ones.  Over extruded layers will stick out slightly.  I bet this isn't the cause but it's one of many you need to check for.

[GregValiant 1,410]

There is an AnyCubic group on Reddit and you can search there for possibilities.  Going through everything would be a huge list.

First and foremost would be to calibrate the E-steps/mm.  If the printer is asked to deliver 100mm of filament but only delivers 90mm then there will be under-extrusion.  The "Steps/mm" setting in M92 controls that.  There are a lot of YouTube videos on how to do it.

 

I mentioned the color difference in bands on the print, and flecks of black in the print.  If the hot end temperature is bouncing up and down you can get burning instead of melting.  If the end of the bowden tube is burnt, little pieces of char can break off.  That might be what the black flecks are.  If a fleck is big enough it can cause a partial blockage in the nozzle and cause under-extrusion.

There is a calibration for the hot end called "Auto Tune".  Doing it will require an interface like "PronterFace" that will allow you to send commands to the printer over the USB and to view the responses in a text box in the interface.  I'm sure there are videos on doing that as well.

 

After the calibrations are run and the new settings are in the printer, the settings must be saved in the printer.  All of that is firmware specific so checking the Reddit site and the AnyCubic site for what would be required is a good idea.

[jojomw3 0]

Ok thanks to both of you for your messages!