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

Re: Horizontal lines in test tower

Thu Nov 23, 2017 8:17 pm

For the most part I am very pleased with the printer. It prints much better than I had anticipated.

Yes that is the first layer. The outside lines are the skirt...I always print a skirt to prime the extruder. The top pic is with a 0.6 Extra Restart Distance. The bottom pic is with a 0.0 Extra Restart Distance. You can see the 0.6 is much better so a negative restart value is only going to make things worse.

I only print from SD card. I use my computer for gaming so I don't want any extra resources being taken up by the printer...or any crash caused by a game to interrupt my print. So it is safest if I use the SD card.

As for the blob, if you refer to the one circled in blue in the attached pic that is from where I stopped the printer. If you are talking about the one circled in green...I don't know why it does that. I only know that when I put in a restart distance that goes away.

There are 3 parts printing at once...the pics are from the part printing in the back right hand side of the print bed. The print for that piece starts at the red circled area and prints around counter clockwise. I don't notice any pause in the printer at that point. The area where there is no extrusion or it looks like it didn't adhere is actually the starting point of the print for that piece. Hence why I put the extra restart distance in it.

I thought about what you said about needing a clean nozzle when switching materials so I put a brand new nozzle on...I'm still having issues with holes in the print :( I really wish I could figure out what is causing them...
Attachments
restart0a.jpg

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

Re: Horizontal lines in test tower

Fri Nov 24, 2017 5:13 am

I'm sure you are printing to hot - and with a to large LayerHigh which is added to the distance between nozzle and bed.
This distanz is unknown for S3S, you must adjust it with the settings for the FirstLayer.
Read this : https://forum.simplify3d.com/viewtopic.php?f=8&t=1941

The interruption with the blue marked blobb shows it: the nozzle is leaking extremly because
-the material is to liquid (low viscosity)
-the distance between the nozzle and the bed is to large, the material can easy soak outside by the consequence that the nozzle is empty

The bad sticking of the oval object may have different reasons.
My favorite is that the extrusion is clogging of the filament inside the heat block because heat is rising up (by to high temperature - and / or - to low feeding, because the melting process is also a cooling process for the feeder tube).
But additionally it is also possible the nozzle is clawing the print bed caused by
- distorted by bed-heating (we are speaking about 0.1 - 0.2 mm!) to understand as a bulge also as a bumb
- the objekt is laying crooked on the bed; to be controlled with the view of the underside (diving down) and with slicing a skirt to the object without a distance, than the skirt must follow the objects outside line exactly, Any undercutting of the object shows it.
Your settings for the FirtLayer were 90% LayerHigh and 100% Extrusion = 0.40 mm
The FirstLayerHigh cause a distance of 90% of given LayerHigh (0.2 mm) = 0.18 mm + the distance nozzle-bed = ~ 0.15 mm summary ~ 0.33. These void is to be filled with your 100 % extrusion saying the same quantity to the nearly double space. Than the nozzle is not able to press material to the bed with a fine adhesion and the rope is pulled away.
The calculated quantity is depending from the LayerHigh and the ExtrusionWidth and it determies the position of the lines to be printed. Therefore I use th possibility of the G-Code-settings with a negative value (mostly -0.05 mm = 30% of my layer high of 0.15) and this has no influence to line position and the quantity to be extruded, it brings only more material to the bed because the gap is lower.

Your retract settings are depending from your extruder system - direct extruder.
Using Coast (stopps the feeding before reaching the end of line but leks out material) and
Wipe goes back the nozzle the given distance (without feeding but leaks as long as pressure is existing)
all together makes the nozzle empty, follwed by the retract. If a positive RestartDistance is needed is also a question how much material is leaking while the printhead is travelling.
Test it out with out any retracting and / or check on the box at menue Advanced .. Only Retract when ...

H.

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

Re: Horizontal lines in test tower

Fri Nov 24, 2017 12:58 pm

The heat bed is warped slightly in the middle...I've had 2 now that both have the same issue brand new. I print on glass to help reduce the warp but with the tape I have holding the glass now it will include the warp...time to go back to thermal pads to hold the glass.

As for the printing temp...I've tried all the way down to 200* and still get holes in the print. I'm not so concerned about the first layer as adding the restart got rid of all the 1st layer problems. It is the layers further up that I am having problems with.

Ok time to run a test with no retraction...it's going to string like crazy though.

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

Re: Horizontal lines in test tower

Fri Nov 24, 2017 2:27 pm

I wonder if it is my extruder motor skipping...

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

Re: Horizontal lines in test tower

Fri Nov 24, 2017 2:59 pm

... possible, but it must have a reason when printing with Cura it doesn't occure? Speed? Becomes hot, motor or driver on the board?

The holes are anytime at the same places?

Just at the moment I have finished seamless a small print, 2 perimeters, no infill , but I must reduce the speed after some layers from 65 mm/s to 90% = ~ 60 mm/s for better cooling.

H.

Attached pics: Construction > Sliced > Result
Construction.png
Construction.png (111.48 KiB) Viewed 1052 times
Sliced.png
Result.jpg

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

Re: Horizontal lines in test tower

Fri Nov 24, 2017 3:35 pm

No the holes are random. Still get them even with no retraction and no coast or wipe. At 200* it seemed the extruder struggles to feed the filament. It feels much slower when I manually push the filament through and is pretty difficult. Attached is at 220* with no retraction, coast, or wipe.
Attachments
20171124_102510.jpg

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

Re: Horizontal lines in test tower

Fri Nov 24, 2017 8:16 pm

So I decided to take a break on the PETG before I get overly frustrated with it and switched to my testing of PLA+. Interesting that the PLA+ is printing just about perfect on the first try. No holes and only a little bit of stringing. Still getting more zits than I would like but I'll take it...I can refine it from here to get an even better print.

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

Re: Horizontal lines in test tower

Sat Nov 25, 2017 3:44 am

Yes, some filaments are critical up to not printable.

The green PLA I have shown first in this thread is a such one critical material.
It needs settings exactly to the point - temperatures, speed, cooling - otherwise it clogs and I must burn out the nozzle.
The reason is the extremly low glass-temperature, thats the point where the material becomes malleable. Proceeding a retract it is pulled back like chewing gum, restart does not push forward, instead it builds a cork on the entrance of the tube. End of story is the feeder pulley shreds the filament - over and out, shit happens.

Good luck

H.

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

Re: Horizontal lines in test tower

Tue Jan 02, 2018 5:51 pm

Well I finally figured out the issues I was having. The first was my travel speed was too low so that was largely what was causing the stringing. The 2nd is I am getting moisture in the filament. While printing I don't see any steam from the nozzle but when I push filament through I definitely see the steam. I tried using a box with cat litter in it and a hole for the filament to come out of and that has helped...but I still get moisture issues after a couple days of printing. I have a friend working on building me an enclosure for the printer which will be sealed and be big enough for the printer and the spool so hopefully that will solve the issue. In the mean time the box works for short periods of time so I'll just use multiple rolls and switch to a different roll each day so they have more time in the cooler I have for storage with a desiccant to dry out the filament.

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