irregular perimeter corners

[giostark 0]

Here again,

I start to think that here, in few 3d, I'll improve so much my print quality...

The new question (split , but I suppose one solution will solve all of them):

-one corner of this cube is not "perfect". It look like blobby for some layers (first 2 pictures) , then "perfect" for others and than still blobby.

-one other corner is regular  blobby (3rd picture), less evidence or less marked as the blobby of the first corner.

-the other 2 corner are "perfect".

I could suspect it have to do with:

"retraction extra prime amount" ? Now is settle to 0.

"Z-seam alignment" ? "Sharpest corner" is now selected.

"Seam corner preference" ? Now is on "Hide Seam".

"retract before outer wall" is marked.

Or maybe is something else?

Looking at the cube have you some suggestions where to look?

THANKS!

Im printing at 0.5 layer height. (for a fast printing of course and i cant pretend miracles , but my hardware should good enough for a discrete result) my speed is settle on 30mm/s.

OT

Than...i see on the wall a wave effect that before there was not . I  reduced the wall count from 2 to 1 so probably the infill disturb the wall. Ill rise again when necessary.

/OT

[yellowshark 153]

Hi

I am not 100% sure what is causing your problem but I would suggest you try the following settings – you do not list all your settings, so you may be using some of these already.

Nozzle width 0.4

Line widths all 0.4

No. of walls 2

ALL print speeds 30mm/s, including Infill (except travel speed and 1^st layer speeds (if you want to run that slower, I always use 20mm/s)

Outer before inner walls not ticked

Horizontal expansion 0

Infill before walls not ticked

Infill overlap 15%

Infill density 26 or larger

Flow 100%

Retraction distance of 5.5 will probably be OK, you can try both. I use  6.5 for nGen and 5.5 or 6.5 for PLA, depending on whether I remember to switch 6.5 back to 5.5 for PLA!!

I have never used retract before outer wall – not sure why you would want to do that.

I have never used a layer height greater than 0.300 so I have no idea if that could have any impact.

Ok Z seam. I always use Random; I am not saying that you should. I do not know why you have selected Sharpest Corner – you are printing a cube, all corners are 90 degrees and so all corners are equal sharpness.

You do not say what you extrusion temp is, which is rather important! Print as cool as you can to avoid any over-extrusion on corners as the print head decelerates and accelerates.

Edited January 17, 2019 by yellowshark

[giostark 0]

Hi yellowshark,

You are right...sorry for the missing settings. I opened a recent post where I described some of them.

Smartavionics found that problem was related to an excessive retraction. I was using a 5mm but it sucks some air and then during extrusion were generate that tiny holes on the perimeter. 2mm was enough for solve the problem.

Concerning you suggestion i have already tested your settings apart the "seam" variation.

I selected it supposing to reach a better result but maybe I'm wrong.

This is my FIRST 3D printer so is all new. I read a lots but seems never enough.

I converted a Tevo Little monster for a medium print volume. I changed almost all the electronic parts and some mechanical.

https://forum.duet3d.com/topic/8397/tevo-little-monster-duetwifi-touch7-my-conversion

 

I list my actual settings and other spec.

-Material is ABS (AppolloX from Formfutura) Seems it is less prone to warping , not free from it but quite less.

The temp is 210 despite the suggestion from the box. More than this the filament seems become inconsistent and pop. Like this is perfect. Is mounted on a original D3D+volcano extension.

The extrusion flow is calculated on 94% for reach the right size of the wall.

-im using the white glue for the adhesion on a custom borosilicate glass 110 degree. It seem to work good. Ill see further upgrade if i cant reach my goals.

-The speed are all settled under the 30mm/s

-Nozzle is 0.8

 

I give a try to to the "zeta seam alignment" and report it !

Thanks for your time!

 

[giostark 0]

Nothing to do with seam alignment on "random" . It seems the problem was moved elsewhere but still persist.

I'm trying with "shortest" . Let's see if something change.

 

[yellowshark 153]

Ah, ABS, all bets are off! I have never used it so you need someone who does to best advise.

I would have thought with ABS 210 was too cool; but you need someone who knows what they are talking about 🙂

[yellowshark 153]

Ok a few comments on your settings; I am not sure that the material would make any difference with these

If I were using PLA with 0.5 layer height I would use two top layers to see if that gave me a better top finish. To me a thickness of 0.5 for the top layers seems marginal; but of course I have never used 0.5 layer height so it may be OK. It may be that with this thicker layer height and 60% infill you are OK.

I would not print outer wall first. Perceived wisdom is that you are likely to get a better surface by printing outer wall last.

I have never used optimise wall printing order and  have no idea what it attempts to do. But you only have two walls, with the order specified in the above sentence, so I would be inclined to untick that.

Skin overlap % hmn never used that although I see I am doing so unwittingly. The  setting is calculated and mine shows 5%. 40% looks awfully high, although with a wall width of 0.8mm you might well be OK; a setting which potentially impacts the outer wall so you might want to try reducing it considerably just to see.

Skin expand distance; again no idea what that does, but guessing, why do you want your outside wall (if that is what skin is) to be 4.8mm wide rather than 4mm wide. Again it is one of those settings that looks like it may affect the surface and I would untick for now.

Retract at layer change; again another I have never used in 5 years. Might be worth turning off to see.

Retract distance 1.5; wow I assume ABS does not leak as much as PLA!

[giostark 0]

Hey Yellow,

It seems that the "shortest" value help a lot ...see , now 3 corner are more or less fine (as the last picture) but still one corner present those strange shape (1st picture).

I'll investigate all your suggestions and also will make some other test and report it !

 

[burtoogle 513]

Hello @giostark, I nearly always use the user-defined z-seam alignment with x and y values that force the z-seam to be on the edge I want. I don't use the other z-seam modes (nearest, random, sharpest corner).

[burtoogle 513]

Thinking about achieving a good quality z-seam, I think the single thing that has made the most difference was fitting a Bondtech extruder. I had previously used 2 other types of extruder on that machine (a Kossel mini) and the Bondtech just blew them away in terms of print quality.

Edited January 17, 2019 by burtoogle
Too much thinking!

[giostark 0]

Thank you Smart!

I have the Bondtech extruder:

 

So I have a bunch of things to test and try !... Thank you both , I'll report about my experiments.

[burtoogle 513]

Ah, yes, it looks like a BMG which is what I am using. Nice bit of kit...

[giostark 0]

Ok I definitely discovered the culprit.

https://mattshub.com/2017/07/19/layer-seams/

-I tried to disable seam compensation and nothing change. (all the options present the problem).

-Printing the inner part before had a bad impact on the shape so is not an option and the problem persist in any case.

 

So..it look like there is an extra extrusion at the end and restart of the layer. In my cube this happen just in some area of the corners because the layers change for the other portions of the corners happen where are impressed the letters! So are hidden but they are still there. So is a problem of amount of material at layer change.

 

I'm going to try the coasting option.

 

If you have advises I'll try them all. 😀

 

@yellow - yep it seems that that retraction work fine but i cant test also other setting. I never tried PLA. For my purpose it didnt have the mechanical strength i need.

[yellowshark 153]

Hi @giostark funnily enough I was going to suggest trying Coasting in my last email. I tried it when it first became available, 2 years ago?, and recall I met with some success. But I am not using at the moment and cannot recall what caused me to remove it - but worth a try!

[yellowshark 153]

...Maybe it was nGen I used it with.

[giostark 0]

Nothing to do for now. I switched to MatterControl for the moment. I need to do tons of experiment and attempts to figure this out and unfortunately i must make this printer work.

When I'll have more time I'll return back to fight in.