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Perimeter and infill not touching

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Dear all,

I finished a printjob again, but wonder why the inflil and perimeter is not touching.

It looks like the perimeter is not really fused with the infill:

SujuLwg.jpg

(click on the image to see it in full resolution)

Just that you get the correct imagination of the size, the vertical tubes have a height of 20mm and diameter of 6 mm

Nozzle size: Stock nozzle 0.4 mm

Material: Inofill3D violet, printed at 220°

Cura settings:

I used the 'Fast print' from quickprint menu, then switched to 'Full settings' and set:

- Shell thickness from 1 to 1.2

(since the yellow background and the hint told me that the shell thickness is not a multiple of the nozzle size)

- Bottom/Top thickness form 0.6 to 1.2

- Speed from 50 to 35

What is the reason for that? How to get a better connection between infill and perimeter?

Edited by Guest

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Hi dirkdirk,

If I give some pressure to the belts with my fingers they feel very strong, so I don't know if this is the reason. I doubt that I can get them stronger if I loose the skrews, press down the motor and fix the skrews again.

Here two other pictures, done with an USB microscope, may someone can judge better:

nWdnk1C.jpg

QnhgjJ4.jpg

(click on the image to see it in full resolution)

IMHO it looks like if the diameter of the filament is too small for some reason between the infill and the perimeter. I wonder that there is this clear gap almost same size around the whole part.

I did a test print as you can see in the upper image. There everything looks fine. It shows the 2nd layer of a 10mm circle with 10 lines of brim.

I used the maintenance function 'Move material' and pushed out a few cm of filament. Then I measured the diameter, it is always between 0.35 and 0.45 mm.

Maybe I have to tweak some settings in Cura?

 

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Hi TinkerGnome,

this is what Cura layer view shows:

E1r02vm.jpg

I did not test with Shell thicknes 1.0 yet since Cura shows this hint that shell thickness should be a multiple of nozzle size, and I think the Ultimaker team has a reason doing so - or not?

But I wonder that the 'Fast print' option uses a default shell thickness of 1.0 mm by default and at the same time Cura shows this hint that it should be a multiple of nozzle size!?!

Either the default setting sould be 1.2 (as a multiple of nozzle size) or Cura should not show that yellow hint - both together is very confusing...

But the question is still, why I get this gap between infill and perimeter and how to get rid of it?

 

 

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Well the way I am looking at it, your infill is fused to your perimeter. With 1.2 you get 3 walls and it looks to me like there is a gap between the middle and inner wall.

What filament width setting have you got and, measuring along a 10mtr strip of filament (selectively) what measurements are you seeing.?

What is your layer depth?

What is your infill %?

What are your retraction settings. - that aspect looks a real mess although I will accept that a close up photo, especially if using flash, can make a model look far far worse that it actually is

In your first pic. were the 4 models printed individually, or printed 4 on the bed - was that using "print one at a time" or "print all at once"?

What is your minimum layer time set to?

Just to confirm, the models in pic 1 were printed at 30mm/s and 220c?

You do not say what filament you are using. If it is PLA do you have another filament you can try, something from Ultimaker, Faberdashery or colorFabb?

 

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Hi,

 

here a screenshot of all my options:

4zBx5Cf.jpg

(Click on the image to see it in full resultion)

As I told in my 1st message I used 'Fast print' and then switched to 'Expert'. So Cura overtook all settings from fast print then I changed only:

- Shell thickness from 1 to 1.2

- Bottom/Top thickness form 0.6 to 1.2

- Fill density from 10 to 35

- Speed from 50 to 35

The objects where printed 'All at once'.

I used Innofil3D filament violet.

If I look at the 10mm circle I printed for testing it looks quite nice. There is no gap at all between perimeter and infill.

But this one causes problems - I don't really understand.

 

 

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Hi,

 

I did some further tests with different shapes, same settings mentioned in the 1st post of this thread. Both is PLA from Innofil3D, printed at 220°.

 

But still same issue:

7MLm44S.jpg

(click on the image to see it in full resolution)

 

In the top image you can see how it looks like after the 1st layer was printed. The perimeter is 'far' away from the infill. But only for the square, the circle looks OK at this point.

I tried also with different filament (the green one is PLA, Innofil) and used shell thicknees 1.2 mm and 1.0 mm (1.0mm is what Cura used in 'Fast print'). But no difference :sad:.

The infill paths touch each other and melt together, this you can see in the circled parts. Only in the bottom green part you can see single paths of the infill.

But in all images again this clear 'cut' between infill and perimeter.

I really want to know what is the reason for that.

BTW the prints were stopped at different layers, so they don't show the final result. I just stopped printing once I detected the error again.

I also took away the printed parts during 'hot' printbed, so some parts are warped only because of that.

Thanks for any further help...

 

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Maybe you can try these settings with your circle and square :

Nozzle 220

Bed 60

Layer 0.15

Shell 0.8

Bottom/Top 1.2

Fill 25

Speed 50 everywhere except bottom 20

Initial layer 0.3

If this doesn't work, something with your hardware must be wrong.

Maybe your Ptfe coupler is dead...

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Hi,

@dirkdirk:

The main thing you changed is the shell thickness from 1.0 to 0.8. But what does that mean?

Does it mean I cannot create a wall thickness of 1.0 or 1.2 mm? I cannot belive it!?!

> ...PTFE coupler is dead

What does 'dead' mean? How can I check if it is dead?

@Macua85:

I tested bed levelling with a squared part which almost occupies the whole print bed.

I have good adhesion everywhere, so bed is levelled quite well.

 

I wonder that the first layer of the green circle (first picture) is almost perfect but the square close to it not since there is this gap between the outer and 1st inner paths of perimeter.

And secondly I wonder that there is this CLEAR THIN thin gap between the perimeter and infill - where does this clear gap coming from?

The nozzle size is 0.4 mm, shell thickness 1.0 this means to me UM2 drives three paths and they overlap a little bit.

But it seems not?

I still need some help...

 

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With a shell thickness of 1mm you will cause cura to tell the printer to do two passes of 0.5mm. In other words, you're telling it to over extrude. This can work, but it's better to do multiples of your nozzle.

I also see that you have vastly different speeds set for infill, outer/inner shells etc. Try leaving the travel speed and bottom layer speed at the default values you have now and set the rest of the speeds to 0 (which will make them the same as your main print speed). When you have such large differences in print speed between different parts of the print it can cause "lag" in the extrusion where the printer is trying to catch up.

 

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Hi IRobertI,

> With a shell thickness of 1mm you will cause cura to tell the printer to do two passes of 0.5mm.

Are you sure? If I look at the 'layer view' (see post #5) I see a red outer perimeter and a green inner perimeter which has double width of the red one. IMHO this means Cura creates 3 passes - can you confirm?

What I wonder is that 1.0mm shell thickness is what Cura sets in his 'Fast print'.

So this was not a decision by me, it was a default setting of Cura!

I started with 'Fast print' and switched to 'Expert settings' there you can see 'Shell thickness' was set to 1.0 mm by Cura. It shows also the yellow background with this hint 'Shell thickness should be a multiple of nozzle size)

UM2 drives three perimeter passes as you can see in the image posted in #9.

(click on that image then you get a detailed zoomed view)

If I take a closer look myself maybe there is no gap between infill and perimeter but a gap between the 2nd and 3rd pass of perimeter?

See illustration here:

lRdBtkn.jpg

If yes - how it comes? How to get rid of it?

 

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Hi,

@dirkdirk:

The main thing you changed is the shell thickness from 1.0 to 0.8. But what does that mean?

Does it mean I cannot create a wall thickness of 1.0 or 1.2 mm? I cannot belive it!?!

> ...PTFE coupler is dead

What does 'dead' mean? How can I check if it is dead?

I think your combination of speed and shell is not ideal.

When your ptfe coupler is dead/defect (the white teflon part) the inner walls are deformed so that the material comes out very uneven. You can take the nozzle apart and take a look into the coupler.

Maybe you can print the parts with my settings posted above and report back?

 

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Hi dirkdirk,

I printed now with your settings, except initial layer height. I used 0.2 instead 0.3 because otherwise I could not get good bed adhesion.

The print results with your settings is shown here:

LLnpNus.jpg

The initial layer was very smooth, all paths of perimeter and infill melted together very nicely.

The photo shows the print status after 4 layers of the bottom.

Now it printed two perimeters. The gap is now between the outer and inner shell.

Also the infill of the bottom layers do not melt together anymore, you can see single paths instead of a solid, smooth surface.

What now?

 

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Hi dirkdirk,

can you explain what is so important to print with 0.3 instead of 0.2 for first layer?

I get good results for first layer with 0.2 mm now. And the 1st layer is not my problem, only in the upper layers the perimeters do not touch.

 

 

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Regarding adhesion, if I set 1st layer height to 0.3 mm and the filament noodle has 0.4 mm diameter then the noodle gets 'only' squished by 0.1mm to get a layer height of 0.3 mm.

But if I use 0.2 mm for first layer then the noodle gets squished for 0.2 mm which presses the noodle better into the glass bed. This is what I think. And the result shows I get better adhesion with 0.2 mm instead with 0.3 mm for first layer thickness.

The filament tip looks like this, after changing:

TM2hAVj.jpg

Could you explain what you mean saying my coupler has a small cove? A simple drawing would be nice.

And how could this cove cause the perimeter not connect?

 

 

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I had the same problem. Replacing the coupler works for me. But your tip looks good. Must be something different when printing with Fans off doesn't close the surface.

With small cove I mean your inner wall is not smooth.

Similar like this: http://ultimaker.ipbhost.com/uploads/gallery/album_1654/gallery_36283_1654_311489.jpg

If you go thicker with the first layer the area where the first Layer lays on turns wider -> more adhesion (0.2 doesn't squish more, because the feedrate is slowed down. Afaik!)

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What I did now is to increase the temperature of the nozzle from 220° to 230° and used following settings:

- Layer height 0.15 mm

- Shell thickness 1.2 mm

- Fill density 26%

- Initial layer thickness: 0.2 mm

- Travel speed 150 mm/s

- Bottom layer speed 20 mm/s

- Infill speed 80 mm/s

- Top/bottom speed 30 mm/s

- Outer shell speed 20 mm/s

- Inner shell speed 20 mm/s

This seems to improve it a lot as shown here:

gjPzYHQ.jpg

As you can see the perimeter has no gaps anymore. So higher temperature solved this problem almost.

But the top layer is not closed smoothly. On the left side you can see single passes of filament on the right side the top layer is closed as expected.

What is the reason that on the left side the top layer is not closed? How can I correct this now?

 

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