incomplete layer lines

[micboe 0]

anyone an idea how to avoid this type of defect?

 

ultimaker S5 - 0.8mm nozzle, 0.3mm layer height, polymaker polylite ABS, 

 

looks like layers stop printing way before end of line (to give an idea of scale: product height = 50mm)

 

thanks

Michael

abs08.3mf

[gr5 2,265]

Aren't those the begining of the line?

 

So there was this horrible error in the AA 0.8 PLA fast profile that had the option "retract on layer change" checked.  For no apparent reason.  That was causing horrible underextrusion on my 0.8mm print until I found that (strange) setting checked.

 

I'm wondering if that error (which has since been corrected) somehow made its way into other profiles (ABS).

[gr5 2,265]

Also set all the printing speeds to be the same speed (all 6 or so).  Everytime there is a speed change you can get over or under extrusion.  And that looks like underextrusion I think.  On the outermost layer.  Maybe watch it printing very carefully in layer view and see what happens just before it prints that edge (outer most shell only).

[micboe 0]

15 hours ago, gr5 said:

Aren't those the begining of the line?

 

So there was this horrible error in the AA 0.8 PLA fast profile that had the option "retract on layer change" checked.  For no apparent reason.  That was causing horrible underextrusion on my 0.8mm print until I found that (strange) setting checked.

 

I'm wondering if that error (which has since been corrected) somehow made its way into other profiles (ABS).

thanks for your reply!

 

I didn't see it actually printing the defect as it was at the back right corner of the builtplate (14h full built plate print - 450grams)

 

From the preview in Cura it looks indeed to be at the start of the outer line. Retract on layer change and retract before outer layer were not checked. However before he starts printing the outer layer, he fills in a small gap in the opposite corner parts, maybe there is retraction  (although combing is set to 'not in skin') but he definitely has a travel move of 220mm before starting the outer wall.

 

i used the same chamfer on outside and inside wall, so corner is a bit wider than the rest of the parts wall thickness - next designs I'll use fillets and make sure wall thickness stays constant to try to avoid having to fill in these parts.

 

Ss it best to design a part wall thickness to an exact multiple of the line width (so line width 0,8mm => part thickness 3,2 or 4mm) or just slightly less?

[gr5 2,265]

20 hours ago, micboe said:

s it best to design a part wall thickness to an exact multiple of the line width (so line width 0,8mm => part thickness 3,2 or 4mm) or just slightly less?

I don't know.  This is pretty much impossible to do on curves but you don't have curves.

 

In PREVIEW mode, make sure travel move checkbox is checked and the blue lines are non-printing moves.

 

There are two different colors of blue - one for retraction moves and one for non-retracting.  You can check to make sure it is doing a retracting move before starting to print the "bad" area by seeing which shade of blue it is.

[gr5 2,265]

If it's a non-retracting combing move (as I suspect) there is an option in Cura to retract on combing moves longer than a certain distance (for example 100mm).  I'm pretty sure that feature is in normal cura but if not then it is in the MB version as I use this feature:

https://www.dropbox.com/sh/s43vqzmi4d2bqe2/AAADdYdSu9iwcKa0Knqgurm4a?dl=0&lst=

 

It's called:

Max comb distance with no retract

[GregValiant 1,408]

"So it best to design a part wall thickness to an exact multiple of the line width (so line width 0,8mm => part thickness 3,2 or 4mm) or just slightly less?"

YES for thin walls and NO for walls that will require infill.  A thin wall is trapped.  In a thick structure Cura can fudge the inside infill area so the outside of the wall is correct.

The Z dimension is another story.  To my limited knowledge (someone correct me if I'm wrong please) - Cura will not make partial layer changes just to hit your dimension.  If layer height is .2 and the top of the print is 3.5 then Cura will either make it 3.4 or 3.6.  If that .1mm difference is important then you must make some adjustments to the model or print settings or splice a file together.