InspGadgt
Posts: 34
Joined: Wed Oct 18, 2017 7:59 pm

Re: Horizontal lines in test tower

Mon Nov 20, 2017 12:38 pm

Well in the test prints I started with a 1mm restart value and backed it off until it didn't blob on the start anymore. But I may have to go back to that and just sand off the blobs because I started getting holes later in the print that look like the extruder did not start extruding right away.
Attachments
20171120_002732.jpg
20171120_002719.jpg
20171120_002708.jpg

horst.w
Posts: 795
Joined: Fri Oct 17, 2014 5:00 pm

Re: Horizontal lines in test tower

Mon Nov 20, 2017 3:27 pm

The recommmendations from my seller (filamentwold.de):



PETG – HDglass
FARBE
Blinded White
DURCHMESSER
1.75 mm

DRUCKTEMPERATUR
195 – 225 °C
MAX. DRUCKGESCHWINDIGKEIT
120 mm/s
BEHEIZTES DRUCKBETT EMPFOHLEN?
Ein beheiztes Druckbett bis zu 80°C wird empfohlen.
MATERIALEIGENSCHAFT
Lebensmittelecht
MARKE
Formfutura
DICHTE
1,27 g/cm³
ZUGFESTIGKEIT
50 MPa
SCHLAGZÄHIGKEIT
7,2 kJ/m²
E-MODUL/STEIFIGKEIT
1940 MPa
ERWEICHUNGSTEMPERATUR
75 °C
BRUCHDEHNUNG
120 %


Please attache your factory-file (yes I know - without the model! but it is easier to comment your settings and it comes back ready to use)
Additional I nead the wall thickness and the real diameter of the filament.

Your printer has a separated object colling fan?

H.

InspGadgt
Posts: 34
Joined: Wed Oct 18, 2017 7:59 pm

Re: Horizontal lines in test tower

Tue Nov 21, 2017 1:24 am

195 to 225? Hmmm...my box says 220-250 on it

horst.w
Posts: 795
Joined: Fri Oct 17, 2014 5:00 pm

Re: Horizontal lines in test tower

Tue Nov 21, 2017 4:12 am

Yes 195 - 225°

My example above, the black toolholder, is printed with it. It's a derivate of PLA or similar. Named PETG, HDClass or what ever.

If you have printed with such a high temperature it is possible that the hotend has blocked by ascending heat from the melting chamber into the tube. Than the extruder need a very high pressure to press out filament or it blocks totally.
It's also possible, that your nozzle has burned parts of plastics inside what clogs the drilled hole.
At last when changing from ABS or similar to PLA it needs to clean the nozzle very accurate. The high difference - high to low - between the melting temperatures of these materials makes problems very often.

To determine the right temperature, heat up the hotend and you must be able to feed the filament by hand. Extrude minimum 20 cm and stopp heating and feeding. While cooling down the filament should leak out of the nozzle for 3 - 15 cm.

The PETG / HDClass I have used for the toolholder above is very liquide (low viscosity) when I print it with only 195°. After ending the print my print bed is going down to 180 mm (endscript) and the filament is pulled down with it just to 160 - 170 mm . Standard PLA comes out only 30 - 50 mm using the same conditions.
Rising up the temperature makes my PETG more viscose ! Curiose but reality.

H.

InspGadgt
Posts: 34
Joined: Wed Oct 18, 2017 7:59 pm

Re: Horizontal lines in test tower

Wed Nov 22, 2017 2:44 am

Well as I said the Hatchbox box says to use 220* to 250* for their PETG so this last print I used the following:

Temp: 230*
Speed: 60mm/s
Multiplier: 1.04
Width: .42 (Left this at default)
Retraction: 3mm
Retraction speed: 60mm/s
Extra Restart: 1.0mm
Retraction Lift: .2mm
Coast: 1.0mm
Wipe: 1.0mm
Layer Height: .2
Fan Speed: 0 (The 3d LabPrint guys are pretty adamant about not using a fan to get best layer adhesion)

I tried faster speeds too but the holes got worse.

horst.w
Posts: 795
Joined: Fri Oct 17, 2014 5:00 pm

Re: Horizontal lines in test tower

Wed Nov 22, 2017 5:17 am

Multi to 0.95 max when the real diameter is measured and the setting in menue Others is ok. While printing, you can change it if needed using the printers display knob (Flow +/-)

Temperature, its your turn, test it out or not.


Retract maybe ok, question, the extruder is a direct-one or a bowden? For a direct-extruder 3 mm seems to high and for a bowden it seems to low. Fact is, the retract musst pull off the pressure from the molten material. Using a bowden the filament has to go a long, bending way inside the hose. I have 70 cm bowden and need more than 5 mm of retract to become free of pressure.

Restart you have set positiv 1.0 mm ; that cause the filament is comming out when restartet for 1 mm outside the nozzle. It needs to be zero or better a negativ value. I use always -0.13 mm for my nozzle (is depending from this).

No Wipe and
No Coast at end
your settings 1 mm are good for nothing when using a bowden.

Menue Advanced, check ON ... Only retract when ... and Minimum for Retract >= 10 mm
Also ThinWall Behavior - allow single extrusion (2x) and overlap up to 50 %

LayerHigh I would print it with 0.12 - 0.15 mm max., for the FirstLayer 0.2 may be the best (2 processes).

You are printing a hollow model with 2 perimeters. Therefore must be the extrusion width the half of the walls width.
The best solution is to allow infill (50%) and / or 3 perimeters. S3D will calculate it in the right way!


H.

horst.w
Posts: 795
Joined: Fri Oct 17, 2014 5:00 pm

Re: Horizontal lines in test tower

Wed Nov 22, 2017 5:44 am

InspGadgt wrote: ...
Fan Speed: 0 (The 3d LabPrint guys are pretty adamant about not using a fan to get best layer adhesion)

I tried faster speeds too but the holes got worse.
ABS dont need fan colling , even it is harmful because it supports warping (additional it is recommended to use a inhousing of the printer with a temperature ~ 50°)

PLA and its derivates must have fan colling - I have written it above.
PETG is a modified PET, with nearly identical print conditions as PLA. I have print out several kilos of it without any difficults, using low variies of settings to PLA.

InspGadgt
Posts: 34
Joined: Wed Oct 18, 2017 7:59 pm

Re: Horizontal lines in test tower

Thu Nov 23, 2017 2:18 am

Arg!!!!! I had a long detailed response to the last 2 posts and somehow it got deleted instead of posted. Ok well there are definitely some things I want to try from the suggestions but I'm too tired after two 10+ hour days in a row at work to retype the response...I'll try again tomorrow.

InspGadgt
Posts: 34
Joined: Wed Oct 18, 2017 7:59 pm

Re: Horizontal lines in test tower

Thu Nov 23, 2017 1:49 pm

I measured the filament with my calipers (Man those things go through batteries fast). It measured at 1.75 at most places and 1.73 in another.

I did a temp. tower test and 230*-240* came out the strongest layer adhesion.

It is a direct drive setup...a stock Anet A8. I realize 3mm is a bit high but with the tip being 13mm in length that gives plenty of room to work with. I've gone as high as 4mm but beyond that I start getting jams in the extruder. If I use a lower retraction setting I get really bad stringing.

I used a high restart because I could see often the extruder wasn't extruding right at the start point...it just dribbled out which lead to holes like what is seen in the pictures above. The lowest I can go with no dribbling is 0.6. See attached pics for 0 restart and 0.6 restart.

I was using the wipe and coast to reduce stringing. I'm not using a Bowden setup so it should be fine.

I've tried the only retract and minimum retraction settings in the past with no change in the print...though I didn't go as high as 10mm...isn't that a bit excessive? As for the thin wall settings I left those at the 3d LabPrint recommended settings. I figured with as much of these things that they do they should know the best setting. But it's worth a shot...I'll try your suggestions.

These don't have to be a super fine finish. The stock setting is actually 0.25...I lowered it to 0.20 to get a better smoosh between layers. I will try lowering it to 0.15 but I also don't want to increase print time by much as most prints are 12-14hrs already. Hopefully increasing the speed will help that.

Actually it is only 1 perimeter. The 2 perimeter area is only the first 4mm of each part to make gluing the parts together at the end easier. The parts have their own internal structure designed into the part so infill is not used. If I used infill the plane would be way too heavy.

ABS is not recommended for these models. There are too many issues with shrinkage and flexibility. As for cooling the designers deliberately have the prints set up so that more than 1 piece is printing at a time to give them enough time to cool...but also to maximize the time they stay hot to increase layer strength. That said...all my other prints I do use cooling with a semi-circular duct at 100% fan speed. This is probably overkill...what speed would you recommend?
Attachments
restart06.jpg
restart0.jpg

horst.w
Posts: 795
Joined: Fri Oct 17, 2014 5:00 pm

Re: Horizontal lines in test tower

Thu Nov 23, 2017 5:44 pm

Hi,

I have no experiances with a direct-extruder at all and the Anet specially. But I known a lot of people who are very pleased with it after some improvements.

The pics are showing always the first layer?
If Yes, than there are some issues in the marked area or nearby.

Do you print online by USB from pc or with a SD-card standing alone (so as I do)?
What I believe to see is that the printhead is comming from the right side, going to the left. The printed rope becomes thin. Why???
At the edge it seems that the printer paused (loading commands, baud to low?) and the nozzle lost some material to a thick bobble. Why???
After that it is going to SE and would print the rope to righthand. But there was ether no extrusion or the material does not stick to the bed and the nozzle pulled it away. Why ???

My printer is a Mankati XP from 2014 and I don't know how many spools / kilos of material I have processed in the meantime but it was a lot.
All the time I had 2 spools given back because I couldn't print out anything. After 2 layers the nozzle blocked - why ever (both PLA & ABS silver).
All other problems were caused by non optimal settings. But I guess that 90% of my prints are very fine by the first try.
Temperature, I print as low as possible - following my own test by hand (see above), the suggestion of the manufacturer is only a beginning point, maybe to high or to low because the printers print-temperature is subjective and individually.
First Layer - the print bed has a distance of 0.15 mm to the nozzle. When LayerHigh is 0.15 - 0.20 I set always 120% for the 1stLayer and 130 - 150 % for extrusion - for all materials, speed 50% (from 60 - 80 mm/s standard). Additionally I set in menue G-Code Z to -0.05mm (negative!).
Cooling, I use anytime min 10% for all materials because the fan wind stabilize the temperature to +/- 1°; PLA and similar material I increase it step by step (e.g. 3., 6., 10. ... layer) up to 70 - 90 %, rarely 100%. PLA, its derivates, PETG are not printable for me without cooling, so as ABS and ASA crashes with it (...10% max).
AND when changing a material-spool I print some test-cubs to adjust my settings.

H.

PS.: there are existing some ABS or ASA filaments with very low or without warping. An additional advantage it will be the lower spec weight 1.25 : 1.05 that makes ~ -20% for your application and the much better temperature manner.

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