Underextrusion...some of the time
All,
Trying to troubleshoot why I have been getting under-extrusion. Testing setup below is 4 half spheres. The sphere in the upper right is not extruding enough PLA. The nozzle gcode instructions move from upper left object to upper right object, starting at the 9 o clock position of the sphere, going counterclockwise. It seems the nozzle will travel to the 3 o clock position before extruding the proper amount of PLA. 3 perimeters, 10% IF.
What I have tried:
-Re-seating PTFE tube in heatbreak (multiple times)
-Bottom where PTFE tube sits seemed clean, but I cold pulled anyway.
-New nozzle
-Raised heatbreak up
-Reduced tension on idler.
I'm confused why this is happening to only the one sphere. I'm assuming this happens due to the retraction, then pressure is lost, and takes a small amount of time to build up again. But why isn't this happening to all the spheres? If I print 1 object with continuous layers, I don't see an issue.
Any help would be great!
RE: Underextrusion...some of the time
Retraction is certainly a possibility but I cannot figure why it would only be in the back corner. Retraction can cause under extrusion when the filament cools and causes a partial jam or when it reduced grip on the filament (chews). Neither could happen in a single location on the bed. They would tend to happen whenever there is retraction. I would reduce retraction and see what happens.
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Chuck H
3D Printer Review Blog
RE: Underextrusion...some of the time
Something I have been pondering, but is there anything that would affect the printing when changing layers?
RE: Underextrusion...some of the time
Could something about that position be causing the filament to drag as it comes off the spool or the spool not to roll as easily? I know when I print flex I used to see underextrusion at the extremes of the bed and I fixed it by adding PTFE tubing through the lid of my Lack enclosure.
PTFE
I changed out the main PTFE tubing, and removed the PTFE tubing going into the filament sensor. This seems to have fixed the issue. Also, while changing the bowden tube out, I realized the compression fittings could have been too tight.