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redslifer

2 years of unsolved stringing

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Posted (edited) · 2 years of unsolved stringing

Hi.

This is the best stringing test result I've had so far in 2 years.

I switched to BMG extruder, tried V6 and Chimera, ptfe lined, all metal, titanium polished bore, high temp PTFE, high rpm 40x40x20 heatsink fan and thermal paste on the heatbreak (it is ambient temp).

Estep and Flow are calibrated.

I tried all materials from different brands and also tried again drying them.

I tried all retraction distance from 0 to 15mm and all speeds from 15mm/s to 80 mm/s and all temps, for PLA from 180 to 230.

I even tried coasting and disabling part cooling fan.

It didn't make any visible difference.

Travel speed is 200mm/s...

 

Any idea on what the hell could the issue be???
Because I am exhaust...

It initially was a creality cr10S before all the mods I did trying to solve this.

 

stringing.jpg

Edited by redslifer

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Posted · 2 years of unsolved stringing

In my experience stringing increases with higher temperature and with better quality material it decreases.
But hey, do not make life harder than it needs to be: these strings are so easy to break away, so just ignore this effect!

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Posted · 2 years of unsolved stringing
1 hour ago, UbuntuBirdy said:

In my experience stringing increases with higher temperature and with better quality material it decreases.
But hey, do not make life harder than it needs to be: these strings are so easy to break away, so just ignore this effect!

In actual prints they become so much that they require an eternity to remove and sometimes they ruin the details.

;(

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Posted · 2 years of unsolved stringing

Those are (mostly) not “stringing”, but antennae. Caused by totally different things.

 

Those offshoots are caused by a drop of ooze building up during the move between the columns. When the nozzle gets to the next section, the drop hits the old layer and deposits there. When it comes to that spot again next layer, the drop deposits on the previous blob. Hence the outward and upward growth of the antenna. 

 

Stringing is where the material does not leave the prior part cleanly, and a thin string connects between two sections. You see some of those between the part and antennae.

 

Try fine tuning retraction. Too much can be as bad as too little since you don’t want to suck air up into the melt reservoir.

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Posted · 2 years of unsolved stringing
13 hours ago, johnse said:

Those are (mostly) not “stringing”, but antennae. Caused by totally different things.

 

Those offshoots are caused by a drop of ooze building up during the move between the columns. When the nozzle gets to the next section, the drop hits the old layer and deposits there. When it comes to that spot again next layer, the drop deposits on the previous blob. Hence the outward and upward growth of the antenna. 

 

Stringing is where the material does not leave the prior part cleanly, and a thin string connects between two sections. You see some of those between the part and antennae.

 

Try fine tuning retraction. Too much can be as bad as too little since you don’t want to suck air up into the melt reservoir.

Yes indeed, "insect antennas". I see this on PET too. Printing slower and cooler helps a bit for me, since there is less pressure build-up in the nozzle, and it leaks less. But I don't know a way to eliminate it.

 

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Posted · 2 years of unsolved stringing

I tried all the possible combos of retraction lenght and speed from 0 to 15 and I didn't see any improvement unfortunately.

I saw that video already too but it doesn't contain anything new 😕

All the materials I tried string the same way.

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Posted · 2 years of unsolved stringing

I never had that thin string between the different parts, only solid drops of plastic.

The following image is the result I have with retraction disabled or set under 3 mm, it is just the same:

https://i.imgur.com/Hcu5ezo.jpg

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Posted · 2 years of unsolved stringing

I guess it would look exactly the same with retractions turned off (you can try it).

 

Actually it looks like retractions do not work on your printer.

CR-10 has an extruder with bowden tube, right? In this case: take sure that the bowden does not move - it has to be steadily fixed on both ends (feeder and extruder). The bowden tube shall never move (in longitudinal direction) - only the filament inside.

 

And be aware that retraction speed (or more generally: speed for each axis) is usually limited by the firmware. In most cases it is unnecessary to try crazy high speeds, because the printer will never reach it.

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Posted · 2 years of unsolved stringing

If you haven't tried these yet, they've helped me in certain applications. If you are using Cura make sure Combing is turned on and try a z-hop of 0.1mm. This is all done using the lowest temperature that you can reliably print with a given filament. 

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Posted · 2 years of unsolved stringing

My bowden fittings are clipped so they don't move.

As I said retraction hardly has any effect on end result most of the times.

I can print at 180+°C but even at that stringing is very high with all the brands I have tried.

I tried combing on and off but no difference either..

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Posted · 2 years of unsolved stringing

 

5 minutes ago, redslifer said:

My bowden fittings are clipped so they don't move.

As I said retraction hardly has any effect on end result most of the times.

I can print at 180+°C but even at that stringing is very high with all the brands I have tried.

I tried combing on and off but no difference either..

Z-Hop may help then and it doesn't take much... When I switched to an E3D V6 on my Ender it seemed as if the heat radiating from the nozzle mixed with its proximity to the printed material was causing the nozzle to pull from the material already printed and then crossing over and the hop eliminated about 98% of that issue (This is with a Bulls-eye duct. as well) That might explain why no amount of setting combos were working.

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Posted · 2 years of unsolved stringing

I tried the zhop as suggested. A low zhop didn't make any change, but a zhop = nozzle started to make a difference, though I am unsure if it is supposed to be better or not. However it changed the solid trees to hard strings.

 

20191025_225558.jpg

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Posted · 2 years of unsolved stringing

Have you tried contacting E3D about this issue? I just remembered your using a geared extruder which I'm not familiar with using so I don't know how that could be effecting the way you do you retractions but, they might know exactly what's going on here. Also if you haven't verified your hot-end temperature is displaying accurately I would recommend you do so if you are able. 

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Posted · 2 years of unsolved stringing

I tried using S3D's wipe nozzle feature and it goes rid of all of the solid parts, only very little points were left which I wasn't able to delete, but it isn't bad.

It seems I'll be forced to abandone Cura if a nozzle wipe feature like s3d isn't implemented

 

s3d wipe.jpg

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