Poor quality print with Ultimaker PC with default Cura 4.8 settings

[yetAnotherUsername 4]

Hi,

So I just tried to print with a brand new Ultimaker PC using default Cura 4.8 settings (Engineering 0.15) with an AA 0.4 head. Ok, I did modify two things: I enabled blob and disabled brim (since the print has a large bottom surface). I used a liquid paper glue for adhesion. I priinted with doors closed and with an extraction fan in the hood (not very powerful though). The issues are (see attached pics):

- "hairs", some of them burned (I used this head for tough PLA before - can that be the reason?); there are even hairs in the fan!

- relatively poor surface quality

- poor adhesion (maybe I should have enabled brim...)

 

Anyone would have an idea what wen wrong or how to improve it?

[Gero 54]

Never heard of this adhesion stick you used. Gonna recommend Magigoo for pretty much everything. I used almost all different varieties they got and so far they all work great. But most importantly, make sure you spool is dry. I wouldn't trust new spools completely. I print all my spools from a heated chamber which runs at 40-45°C 24/7. Getting those fine stringing "hairs" everywhere indicates a possible wet spool.

[AppNinja 0]

@Gero what is this heated chamber you are using, do you have a link you can share?

[Gero 54]

It is actually a food dehydrator which I modify to suit as a spool heat chamber...
It's this one here: 

https://www.amazon.de/gp/product/B0012US5Q8/ref=ppx_yo_dt_b_asin_image_o08_s00?ie=UTF8&language=en_GB&psc=1

 

 

[marine3D 6]

Hi @Gero, any chance of a link to the files for the adaptors to feed the filament. Nicest ones I’ve seen!

 

Thanks

[kmanstudios 1,120]

I would still use a brim (pretty big one too) as it will help hold down the edges. The edges can lift off without that extra help as you saw. I think it has something to do with how the infill cools and pulls the edges inward.

[geert_2 557]

I would also use brim, because steep overhangs also tend to cause huge warping forces, and in addition they tend to curl up.

 

If you don't want a brim all around the model, design a custom one in CAD on the places where you need it. A custom brim gives you the option to make it thicker too, if needed, for example 2 or 3 layers.

 

Try if your bonding method can hold an inverted prism down while printing. If yes, 99.9% of your other models will work too, because this is a hard test.

 

This one is going to succeed well.

 

This one might soon come off and produce "spaghetti", or it might barely survive. You see the warping due to the steep overhangs, and the curling-up of the edges, which makes the nozzle bang into them, and excert huge additional forces.

 

Try such a small test model, to find the best bonding methods for your materials and models, and add custom brim as required to make it print well. Stay with the printer and watch closely what happens, so you can abort, and so you learn from the observation.

 

[JohnInOttawa 104]

I know rafts are considered an obsolete technique, however the introduction of breakaway has, for me at least, revived this option for my nylon/glass and nylon/CF prints where I needed very flat and very matte on both lower and upper faces.  I haven't tried polycarbonate yet, it's actually next, so I'll try that and post results.

 

The breakaway adheres beautifully to the glass and the materials I've used to date stick to the breakaway but come away cleanly post print.  If it is a must do project with one of those materials, that's my goto technique now. 

 

Wishing everyone a chance at some peace and a break from worrisome news for a while over the holidays.

 

John

[geert_2 557]

2 hours ago, JohnInOttawa said:

I know rafts are considered an obsolete technique, however the introduction of breakaway has, for me at least, revived this option for my nylon/glass and nylon/CF prints where I needed very flat and very matte on both lower and upper faces.  I haven't tried polycarbonate yet, it's actually next, so I'll try that and post results.

 

The breakaway adheres beautifully to the glass and the materials I've used to date stick to the breakaway but come away cleanly post print.  If it is a must do project with one of those materials, that's my goto technique now. 

 

Wishing everyone a chance at some peace and a break from worrisome news for a while over the holidays.

 

John

 

Hi John,

 

I think this is a good idea. And if it works for you, obviously, it works.

 

If you would like, feel free to use my old warping test, shown in the photos above. I would be curious about the results, to see where the limits are?

 

This is a small test that prints quickly: total model size = 50mm x 50mm; height=5mm; top-width of each arm = 10mm, bottom-width = 2mm. So, a tiny bottom area to bond to the glass, but a huge top area to produce warping forces, combined with steep overhangs peeling the model off the glass. And overhangs curling up.

 

 

warptest11.stl

 

 

[Travis7s 25]

In my experience with Ultimaker PC, it does generate a lot of very fine hairs that clog the fan quickly, to the point where I am cleaning it daily. I haven't tried any other brands so I'm not sure if this is a normal thing for all PC.