Strange wall problem

[ewad 0]

Hey all 

At my work we have an Ultimaker 3e  and we have had some problems it. 

at the moment we have a problem we cant seem to find the solution for. 
Sometimes a print will get wierd looking underextruded walls in model specific places. At the pictures the problem is shown on the indside walls, while the outside walls looks fine.  
we use PLA and the stock settings for ultimaker 3e in cura.
To me it looks like a softeware issue, but im not sure. 
 

 

 

[gr5 1,762]

That's picture perfect, typical underextrusion.  So now you know what it's called.  But we still need to fix it.

 

First thing I would try is to lower the speed by 50%.  It's only extruding about half what needs to extrude so I would cut the speed by about 50%.  Also set *all* the speeds the same.  Everytime you speed up, you get underextrusion for a little while until things balance out again.  So also make all the speeds the same (infill, inner shell, outer shell) and make them all half what the outer shell speed was.  At least as a test.

 

Also you could look at the model in slice view and see what happens just before this underextrusion.  maybe it's a layer change or something that might give a hint to the issue.

 

You might want to try your other core (your printer should have come with two AA 0.4 cores) to see if the problem is with the core.

 

[gr5 1,762]

I just noticed when zooming in that the "top" surface on the inside of your box also has underextrusion by about 30% (30% gap between each line).

[gr5 1,762]

If you want to print much faster, it's best to go with larger nozzles.

[ewad 0]

I might try switching the printcore.

 

What I don't get is.This model is fairly large (13cm x 13cm) how can it be it's able to print the outside walls fine, while the inside gets underextruded? It's almost the same distance, acceleration and speed the printer has to go through on the in- and outside walls.

 

And yes I could try adjusting the different speeds, but shouldn't the printer be able to print With the stock ultimaker settings in cura.

I didn't mention this in the beginning, but it's not a problem that happens all the time, it may happen every 10-15 print.
I think it happens on straight walls. 

 

We have an ultimaker 2+e also and we never had an issue like this with that printer. 

[ewad 0]

What i also wonder how it sometime can be a problem for 4mm on a wall and looks fine beneath and above the underextruded line. And this is with no geometric changes in the model.