Print gaps. Marlin settings, slicer settings or mechanical?

I have now upgraded my A-101 to an E3D-V6 hot end.

Now I'm back to figuring out the problems that I set out to figure out before I buggered the old nozzle...

The photo below is of the right most (positive X) corner of a 20x20x20mm cube. Note the layers near the corner are curling upward.
The effect is seen in all 4 corners, and strats to get noticeable about at about 25% of the over height.


The more concerning issue is shown in the infill in the top layer/s. There is a gap that is most pronounced on the right side.



Since this was the issue before the nozzle was replaced, I'm guessing that this is not a nozzle issue...

This print was done with a 0.4mm nozzle, 0.2mm layer height, 5 top layers, and 30% overlap.

At this point I'm looking for ideas and recommendations for trouble shooting.

I have tried overlap settings, that seemed to have no effect...that confused me.

Regards,
Mac

what is your bed temp and hot end temp?

have you calibrated your printer axis and extrusion?

are you sure the slicer has the correct tip size?

I see 'elephant foot' that makes me think your bed is too hot, the layer adhesion often can be several issues from cold extrusion to under extrusion etc
do you have a fan on your hotend to cool extrusion as deposited?
I use this setup on mine:
[www.thingiverse.com]

The bed temp for that print was 110, hot end 230.

Not sure how I'd calibrate the extrusion. (I assume you mean the amount of filament being pushed through the nozzle.)

I only have a cooling fan on the the hot end (i.e. on the cooling fins above the heat break)

I did double check the setting in Slic3r for the nozzle diameter before I created the gcode.

I'm guessing the x and y are close to calibrated since it is a 20mm cube and the the x/y dimensions are 20x20.1. The z is 19.85.

When you say 'elephant foot', do you refer to the brim or the deformation in the mid layers? I have used the brim, almost from day one, since the abs slurry never seemed to be enough to get good adhesion.

I would also note, at one point this printer worked well. And then started giving me grief...of course I can't pin point a time or what changed.

Quote
drmacro
The bed temp for that print was 110, hot end 230.

Not sure how I'd calibrate the extrusion. (I assume you mean the amount of filament being pushed through the nozzle.)

I only have a cooling fan on the the hot end (i.e. on the cooling fins above the heat break)

I did double check the setting in Slic3r for the nozzle diameter before I created the gcode.

I'm guessing the x and y are close to calibrated since it is a 20mm cube and the the x/y dimensions are 20x20.1. The z is 19.85.

When you say 'elephant foot', do you refer to the brim or the deformation in the mid layers? I have used the brim, almost from day one, since the abs slurry never seemed to be enough to get good adhesion.

I would also note, at one point this printer worked well. And then started giving me grief...of course I can't pin point a time or what changed.

I did not realize that was ABS and assumed it was PLA. ABS is much harder to get right than PLA and alot of peeps give up before they get ABS dialed in....

Read thru this and work with it carefully.
[www.instructables.com]
It should get you dialed in as far as mechanical movements are concerned.

after that, dial back your temp a little, the 'elephant foot' is a reference to the wide part against the bed. Its usually caused by the bed being too hot but I may be seeing the brim its hard to say in the pic.
I print ABS with my bed at 90 on a PEI sheet. Works pretty good. That said I have not done ABS since I did my E3D head....
I would drop 5 degrees on the bed and 5 on the head and look at the result.
if its improved - drop the head another 5 and compare...

OH! That cooling fan I suggested is NOT to be used with ABS..... Thats why its easily removed...

another thing to look at is speed, oddly if you print too slow with ABS you can cause the abs to cool to slowly as its exposed to the radiant heat of the hotend block too long...
I have a silicone sock on my hotend to help with this.

I assume you have your printer in a case of some form to keep drafts away and prevent your ABS from cooling unevenly...

[www.matterhackers.com]

First thing you will notice is drafts cause layer separation....

That might be the core of your issue right there......

On a finishing note, if you don't NEED ABS for the strength or temp resistance it offers.... Work with PLA....
All my printer parts are ABS... but I pretty much don't do ABS unless the part is going to be exposed to some higher temperatures or I need structural strength etc.