Top layer trouble

[LePaul 326]

Is this a case of my shell not being thick enough?

Printed at 214C 0.1 mm 40 mm/s (ColorFabb PLA/PHA)

Edited September 22, 2015 by Guest

[SandervG 1,521]

Yes, it is called 'pillowing'.

[SandervG 1,521]

Well, in theory not your shell, that is just the sides. The top layer is not thick enough.

But it could also be cooling.

[LePaul 326]

Ok...I was using the default setting for the thickness.

What would you advise to change it to? How much is too much?

Thanks!

[LePaul 326]

Well, in theory not your shell, that is just the sides. The top layer is not thick enough.

But it could also be cooling.

 

Well the fan was running when I left it overnight to print, so I think the fan isn't the problem. (Although the bearing has been noisy at start...a tap quiets the noisy bearing down. )

[SandervG 1,521]

That the fan is running is not everything.

The fanduct on your Original needs to be aimed correctly too.

If it is aimed wrong, for example too high (at the heaterblock), it could also give you temperature issues. If it is aimed too low, it cool mostly after it is being deployed.

What is default setting?

I would recommend to add like 3x your layer-height.

[LePaul 326]

Upon reading the link....a few thoughts...

I have fill at 20%. Maybe I should try 25%?

The top thickness is the default value (0.6). Would 0.8 be advisable?

I'm 90% sure the fan is working properly....and since the entire print isn't pillowing, I suspect options 1 and 2 would fix it. (Yes?)

[LePaul 326]

That the fan is running is not everything.

The fanduct on your Original needs to be aimed correctly too.

If it is aimed wrong, for example too high (at the heaterblock), it could also give you temperature issues. If it is aimed too low, it cool mostly after it is being deployed.

What is default setting?

I would recommend to add like 3x your layer-height.

 

The fan shroud is the stock one from Ultimaker. (September 2013 kit)

[SandervG 1,521]

Do you have the metal fan shroud or the (I forgot what it is made off) plastic one?

The plastic is adjustable, the metal one is not.

Like I said, it is not perse about the fan, but the orientation of the shroud could also be of affect.

If the entire thing is not pillowing, it would make more sense to make the top layer a little bit thicker, like 0.8 or 0.9. I don't think that more than 20% is necessary, but you could always try.

Tip; if you first try the thicker top layer, and later a more dense infill, you will know what did the trick.

[LePaul 326]

Yes makes sense to try one item first. Like, as you suggest, the thicker layer

The fan shroud is the plastic one (folded up type)

[SandervG 1,521]

That one is adjustable. By standing in front of it, it should be adjusted in a way that it guides the airflow directly underneath the nozzle. Not against the nozzle, and not straight down.

If you have doubts you can upload a picture of your fan shroud.

[LePaul 326]

I'm glad I kept the PDF of the manual

[gr5 2,194]

Some filaments just don't do quite as well. Adding a few more layers should do the trick. Lowering the temp to 200C *might* help. Going to .2mm *might* help (strings less likely to break when it lays down the next layer). But the safest thing to do is "more fan", "more infill" and "more top/bottom layers".

[LePaul 326]

We'll try this tonight...note i start at 225 then lower it way down to 210 once i have a good flow going....i seem to have poor material flow at the very start of a print.

Edited September 23, 2015 by Guest

[LePaul 326]

Fan was running. Still doing it tho not as bad...

For the second item i brought the temp down to 200 C We'll see how that goes.

@SandervG my fan is failing, any chance it can replaced? I don't have a lot of print time on this printer. Its running but sounds like a bad bearing, especially when it spools up after the first layer

Edited September 23, 2015 by Guest

[SandervG 1,521]

If you get in touch with support we can check your details and determine if you are entitled to a new fan

[yellowshark 153]

I would say that with a 100 micron layer and 20% infill you want your top thickness at least 1.2mm maybe more. This is not a recommendation but personally I never infill at less that 40% Unless I am doing a large base where dropping below 40% could have some real time benefits - 40% makes a significant difference with pillowing.

It seems to me from some observation that the thinner you set your layers the greater the top thickess needs to be, which will be exacerbated by less infill.

If you do not want to change your layers or infill% then the solution is simple - just keep increasing your top thickness until the pillowing disappears

Edited September 23, 2015 by Guest

[LePaul 326]

I would say that with a 100 micron layer and 20% infill you want your top thickness at least 1.2mm maybe more. This is not a recommendation but personally I never infill at less that 40% Unless I am doing a large base where dropping below 40% could have some real time benefits - 40% makes a significant difference with pillowing.

It seems to me from some observation that the thinner you set your layers the greater the top thickess needs to be, which will be exacerbated by less infill.

If you do not want to change your layers or infill% then the solution is simple - just keep increasing your top thickness until the pillowing disappears

 

I think you are correct. Upon the second item just having finished printing, it has fewer pillowing artifacts....but they are there.

Adding to the fill density did help some.

But I like your idea of 1.2 mm for the top/bottom layers

[neotko 1,417]

On the old cura 'legacy?" when the infill it's 26 (no less) the pattern changes, until I moved to s3d I always got good top layers with that.

[gr5 2,194]

If you watch the first layer where you know pillowing will occur you will see that some of the strands snap/break/ So definitely having thicker layers I would expect makes for a thicker and stronger strand. I doubt your fan is worse than any other UMO fan but that is the single most important fix for pillowing. Many people do 2 fans on the UMO to make it more similar to UM2. I didn't find that necessary and still use stock fan and stock fan shroud.

[LePaul 326]

Well it looks like the guys at Dream 3D heard us talking about pillowing....