Spider webs from hades… or excess pla stinginess

[jaysenodell 13]

This is new, but it’s also the first time I’ve run this large of a job. Also the first time I’ve intentionally tried need in Z hopping 

 

I started noticing strings very early in the print but that seemed normal. 23 hour later I changed filament because I didn’t estimate usage well and assumed it was an issue with the black pla and humidity or something. That was wrong as you can see the red is stringy too. 
 

Now remember I’m new to this so expect me to miss the obvious. 
 

I’m guessing this is a retraction setting problem based on my research. What I’m not sure is how to best figure out which of the settings I should be looking at since there seem to be a number of options here. Point me in the right direction please!

 

The 3mf and gcode are in the cura section. The “random flicking of infill” thread.  They are not small. 

Edited February 2 by jaysenodell

[Slashee_the_Cow 269]

Let's have a look at your project and all the retraction moves in it:

Are you sure it's a huge problem?

[jaysenodell 13]

I say huge in the context of "WTF IS THIS!?!?!???!!!!" That and the need to clean all the nubs off from the strings. It's proving to be a bit more effort than expected for a problem that didn't exist in the last runs prior to Z hop. Is there something with the Z hop that would cause this? Do I need to increase retraction amount to reduce these a bit? 

 

I did not adjust wipe nor randomize seams on this one either. I expect that last one might exasperate this a tad bit. 

[jaysenodell 13]

Ok… a different project that I can’t share here is doing the same thing. Lots of “hair” blowing down wind of the cooling fan. Hair seems to originate from lift points. 
 

What is supper fun is the fan will suck the hair into the cage. Here I was thinking the spaniel had been napping on the printer but maybe this thing is just eating it’s own boogers. 

[Slashee_the_Cow 269]

16 hours ago, jaysenodell said:

I did not adjust wipe nor randomize seams on this one either. I expect that last one might exasperate this a tad bit. 

Depends on the way your object is being printed, especially when you're doing multiple objects all at once. I find it tends to even out. Whether wiping is worth it really depends on if your seams are visible, if they aren't then good as wiping might be for reducing pressure in the nozzle it'll make your print look worse.

 

It could be worth trying coasting though, it's the opposite (stops extruding slightly before the seam, the idea being if there's a bit of filament still coming out of the nozzle that'll finish off the wall. You'll have to go into the Experimental section of the print settings to find it.

 

10 hours ago, jaysenodell said:

Ok… a different project that I can’t share here is doing the same thing. Lots of “hair” blowing down wind of the cooling fan. Hair seems to originate from lift points. 

Could be worth testing printing with the fan off. If you're printing PLA it'll be fine without it (unless you're bridging).

 

10 hours ago, jaysenodell said:

What is supper fun is the fan will suck the hair into the cage. Here I was thinking the spaniel had been napping on the printer but maybe this thing is just eating it’s own boogers. 

That's... pretty talented. Also seems like a great excuse to introduce yourself to the world of printing printer modifications: design a shield for the fan that stops it sucking air from that direction.

[jaysenodell 13]

Increased retraction to 1mm on a flange print (attached) and the webbing is reduced-ish. It’s much finer. i have questions for another thread though so more about flange printing shortly. 
 

Back to retraction… what’s my danger here? My brain tells me I may have low booger output on the next attempt to lay material which would be bad for short segments. Anything else?

[Slashee_the_Cow 269]

Don't worry about that, Cura un-retracts after it retracts for a travel move so you have enough pressure in the nozzle when it starts printing. The main thing you have to worry about (and the main reason Cura has settings to limit the number of retractions) is filament getting chewed up by the gears of the extruder by going back and forth too much, but especially with the short retraction distances on a direct drive extruder it shouldn't be a problem if you're using a decent quality filament.

 

If you're not using a decent quality filament, it looks something like this:

(I should have taken that as a sign. A sign to stop using that spool before it completely clogged my hot end to the point of needing to replace it. Oh well, live and learn.)

 

Obviously different materials have different tolerances for that sort of thing but except when I've played around with the settings to make sure Cura retracts Every. Single. Travel. (for my multicolour art prints) the defaults have worked fine for me when I'm not using the second worst filament I've ever used (yeah, there's worse than clogging a hot end and getting chewed up so much I had to cut off about a foot of it. A couple of times).