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AsafBu

Holes on outer shell

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Hi all!

 

I have this weird outer shell hole problem, only when slicing using Cura, looks to be caused by wiping (?) but I'm not sure how to overcome this problem.

Would really appreciate your help!

 

Thanks,

 

Asaf

20180512_134526.jpg

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This looks like a prusa.  Is the feeder mounted on the head (call it "head mount") or does the feeder push the filament through a long bowden (call it "bowden")?

 

Well it looks like underextrusion briefly in one spot on each layer.  and in a different spot.  There are many possibilities, all of which can probably be fixed by the slicer.

 

For one, what is your retraction distance?  For head mount it should be something around 1mm. for bowden it should be more like 4mm.  Having a retraction distance too long will cause this issue I see on your print.

 

Also turn off acceleration control, jerk control, make sure "retraction on layer change" is off, make all the printing speeds (inner shell, outer shell, infill) all the same speed because when you speed up it can cause underextrusion like this briefly.  You can turn all these features back on once you get things working/printing nicely.

 

Try to match up these defects with exactly what is happening in slice view.  I would reload the gcode file into cura to be sure you have the EXACT same one and try to find one of these holes and try to see what is going on.  Cura lets you "play" the part one move at a time.  Dark blue lines are travel moves *with* retraction.  Light blue lines are travel moves without retraction.

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13 minutes ago, gr5 said:

This looks like a prusa.  Is the feeder mounted on the head (call it "head mount") or does the feeder push the filament through a long bowden (call it "bowden")?

 

Well it looks like underextrusion briefly in one spot on each layer.  and in a different spot.  There are many possibilities, all of which can probably be fixed by the slicer.

 

For one, what is your retraction distance?  For head mount it should be something around 1mm. for bowden it should be more like 4mm.  Having a retraction distance too long will cause this issue I see on your print.

 

Also turn off acceleration control, jerk control, make sure "retraction on layer change" is off, make all the printing speeds (inner shell, outer shell, infill) all the same speed because when you speed up it can cause underextrusion like this briefly.  You can turn all these features back on once you get things working/printing nicely.

 

Try to match up these defects with exactly what is happening in slice view.  I would reload the gcode file into cura to be sure you have the EXACT same one and try to find one of these holes and try to see what is going on.  Cura lets you "play" the part one move at a time.  Dark blue lines are travel moves *with* retraction.  Light blue lines are travel moves without retraction.

 

Thank you for your help!

 

I have direct extrusion and Retraction Distance settings in Cura was 6.5 mm by default.

Now I've changed it to 1 mm as you recommended and it works perfectly, no additional changes needed. 

 

Thanks a lot!

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