Hi @Xhoax.
This looks much better and I'll think this are the a bit of "softening of filament" in the cold area of the core.
Remember, a little less retraction "may" remove this -but may also led to more stringing.
You're only using the left (no. 1) core right, -and the right (no. 2) core are not USED during this print.
If you want to improve the cooling flow to core no1, core no2 can be partly blocked by rolling a length (1.5 turn and lock with scotch tape) of paper around the cooling fins leaving two fins open for cooling the electronics in the back.
This might increase the air flow from 100% to approx 135% through core 1, if you're lucky.. You may use an old core for this purpose.. This might be enough for you to have success with this experimental printing..
So, remember to remove this "modification" after this special printing.
Sure, -this is not something Ultimaker recommend.
An air-conditioned printing office would be a perfect solution.
Thanks
Torgeir
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Torgeir 267
Hi @Xhoax,
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Xhoax said
With the 0.6 we are printing and the error doesn't occur. But there is some underextrusion. See photo below.
UMS3(photo)
We did the test printing at 195° and flow 100%
Wall speed 30
Infill speed 45
Retraction distance 4.5 and speed 30
The Tower thing wint help because the underextrusion is only after few hours. We alsof notice that the infill the lines from left onder to upper right are good.
And from right under to upper left are bad.
How??
I don't think this is better, what can we try to improve this?
---------------------------
Well, -this filament are not easy to deal with, so lets look a little more into this filament.
From the properties for a clean copper, we know that copper is a good electrical conductor -and this are also true for the heat transmission. Also, just to mention, -this filament bring us into the "experimental" mode -as there are no "official" profile for this filament, yet..
After looking into your pictures, it made me think that this are a kind of friction making this fluttering lines.
So, during printing the heat transfer much faster along the filament due to the high amount of copper infill.
This may soften the filament above the teflon insulator adding more friction to the feeding of the filament -and this could be the reason for uneven extrution/under extrution that's become visible in the print object. It may take some time for this to occur.
I'll assume that you're printing only with nozzle no 1, right? (Cause your support are also printed with same filament?)
If the above is right; "how can we prevent this softening of the filament in the "cold" zone of the nozzle unit?"
There are (at last) two ways of doing this, printing without using the heat bed
and/or improve the cooling of the nozzle no 1.
So to your settings:
I would increase the flow to (103-105)% this as "infilled filament" always need more flow than "clean" filament, due to the added friction by high density filament.
Speed: You better use the same speed for all print setting (outer, inner and infill), I would go with 25 mm/s. (Steady speed are important with this type of filament, as often speed changes -can create lines due to difference feeding.)
Retraction; I'll think 4.5 mm at speed 30 mm/s are ok. (Normally we use 6.5mm.) This lo distance are used to avoiding molten plastic to enter the cold part of the nozzle. Maybe less retraction than this can help a little, if this is the problem..
3d printing with this type of filament can be very challenging, as small variations in settings can have a big impact on the quality of the object you print.
Hope this can give some improvement to your project.
Thanks
Torgeir
Edited by TorgeirAdded text.
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gr5 2,238
The infill is likely at a different print speed. A faster print speed. Slow that one down to the speed of the walls which look better. But keep in mind that it's normal for infill to be a bit underextruded as it is intended mostly to hold up top surfaces (similar to support). But not this underextruded.
Tower is mostly only intended to be used when you have dual extrusion to help prime a new nozzle everytime you swap nozzles. For a single extrusion print it just causes problems.
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Xhoax 4
Thank you for this input. I feel like i owe you a drink!
We are making good statues now.
Heated bed off
All speeds at 25mm
Flow 105%
The last print we had a weird thing, the print is super smooth, but we have lines and underextrusion at top of the print.
Is this random? Or can this be fixed?
It was very hot yesterday 35+°C where we are printing. Could this be it.
Thanks again
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