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Still having retraction issues  

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QuinG
(@quing)
Eminent Member
Still having retraction issues

Hey everyone,

I've been playing around with my retraction settings ALOT this last month and i'm so close to the perfect settings for my Prusa i3 mk3s printer but I'm still not there and I'm hoping that somebody could maybe guide me. 

I tried changing the speed down to 35 from 40, I've also tried upping it with no luck. I've also played around with the acceleration control settings and it improved my prints but I still get so much stringing on every print I make. I'll attach the most current prints along with my settings. Thank you everyone! 🙂

 

 

 

Posted : 25/05/2021 11:04 pm
QuinG
(@quing)
Eminent Member
Topic starter answered:
RE: Still having retraction issues

Forgot to mention i'm using PET-G as the filament

Posted : 25/05/2021 11:11 pm
bobstro
(@bobstro)
Illustrious Member
RE: Still having retraction issues

I'm assuming your goal is to reduce or eliminatenthat bit of fine stringing. I've put together my notes on the subject here.

My major takeaways are:

  1. Be sure the filament is dry, particularly if prints with tested settings seem to be getting worse.
  2. Calibrate your extrusion multiplier and diameter for each filament. If your slicer settings don't match the real world, you have small amounts of over or under extrusion which can contribute to stringing.
My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 25/05/2021 11:15 pm
fuchsr
(@fuchsr)
Noble Member
RE: Still having retraction issues

Bob said, adjusting your extrusion multiplier may help. Or turning off Lift Z.

I also found PETG just more "stringy" than PLA by nature. If you're seeing just some residual strings, taking the heat gun to it may be more time efficient than hours of optimization. Maybe intellectually not as satisfying but practical.

Posted : 26/05/2021 10:48 am
Dan Rogers
(@dan-rogers)
Noble Member
RE: Still having retraction issues

In my experience with PETG - which I print nearly constantly - stringing is more a function of filament quality or moisture than it is anything else.  While a lot of the online chatter blabs on about endless retraction settings - I have never, not once, ever had to play with retraction, lift Z or do more than identify the problem and address it.  Too low temp will make PETG string - it is usually coupled with not sticking well to the layers around it - so the excess builds up on the nozzle and you get stringy mess that then builds and builds - making the stringing problem worse.

Have you tried different Brands of PETG?  You will see a bit of difference in them - and even between different colors in the same brand you will need to make temp adjustments.  The built in "generic PETG" starts out at 230C and then progresses to 240.  I have an amazon basic clear red that will not print well at this low temperature.

Another large factor in stringing is first layer live Z (notice I did not say calibration, the two are different, though related).  Dial you z down a skootch too close to the bed (wavy like water) and you'll have stringy print the rest of the print.  Why? Because you're dragging the nozzle thru filament, remelting it on the outside of the nozzle - and thus lose all hope of accurate trace placement.

I have stopped using the Generic PETG profile - for every thing I use Prusament profile and dial live Z to get rid of the stringies.  You not only get a stronger print, but the high temps lead to less stringing.

 

Posted : 27/05/2021 7:20 pm
QuinG, bobstro and fuchsr liked
Peter M
(@peter-m)
Noble Member
RE: Still having retraction issues

Use a hot blow torch after printing.

You could try to use a filament cleaner, inside is a sponge with oil on it, this could prevent what is on your picture.

Your problem is not retraction but stringing, and petg has more problems with that.

You could try a different roll of filament or put roll in a oven to get moisture out of roll.

This post was modified 6 months ago by Peter M
Posted : 28/05/2021 6:26 am
QuinG
(@quing)
Eminent Member
Topic starter answered:
RE: Still having retraction issues

Thank you all for the advice! 🙂 I have noticed differences in the brands of PET-G I've bought. Some, the quality looks cheaper than others. I've read in a couple of places that moisture to filament is bad, but I don't understand how the filament would get wet in the first place. I leave my Filament out in the open in a room thats always kept at 22 - 24 C. So I don't see how it could get moisture on it.

I've also noticed a massive difference in the slicer programs i've used. I havn't had much success in Cura, however in prusa slicer I notice that their generic settings are pretty good.

Posted : 28/05/2021 7:51 pm
muddymaker
(@muddymaker)
Trusted Member
RE: Still having retraction issues

PETG is hygroscopic, which means it will actively absorb moisture from the air. For this reason, PETG plastic should be stored in a cool, dry place, and dried if exposed to humid air for too long.

 

Posted : 29/05/2021 1:21 pm
Peter M
(@peter-m)
Noble Member
RE: Still having retraction issues

All filament absorbs water! (how bad this is depends where you live, and airco or not).

A few weeks ago I saw with my printer while extruding, bubbles, never saw this so bad.

Get a food dehydrator , so you can put 1 or 2 rolls in it, I heated mine at 50 degrees for 6 hours and it printed again good.

Keep your rolls in plastic boxes with Silica Gel.

This one fits most rolls,  LOCKNLOCK classic food container 5.5L 185oz

Posted : 29/05/2021 2:09 pm
Dan Rogers
(@dan-rogers)
Noble Member
RE: Still having retraction issues

@muddymaker

How do I read that chart.  What is the danger?

Posted : 29/05/2021 3:01 pm
Dan Rogers
(@dan-rogers)
Noble Member
RE: Still having retraction issues

@peter-m

I would not want oil on my filament....

Posted : 29/05/2021 3:02 pm
muddymaker
(@muddymaker)
Trusted Member
RE: Still having retraction issues

@dan-rogers

The danger is that your printer will explode if you don't store your filament in a correct habitable environment 😱 

Posted : 29/05/2021 3:51 pm
QuinG
(@quing)
Eminent Member
Topic starter answered:
RE: Still having retraction issues

Thank you all for the tips! 🙂 I have one more question now. People talk about retraction speed and distance a lot when it come to stopping stringing. In Prusa Slicer, where can I find retraction distance? I don't see that option anywhere. Is it called something else in Prusa Slicer? Thank you in advance!

Posted : 29/05/2021 6:10 pm
QuinG
(@quing)
Eminent Member
Topic starter answered:
RE: Still having retraction issues

Also, so after over 30 attempts now, this is probably the best I've gotten it to so far. Any suggestions to my settings? Ill attach my current retraction settings to this too. My travel speed is set to 250. I purchased some new PET-G filament and tested the settings with that just to make sure that moisture isn't the cause of so much stringing.

 

 

Posted : 29/05/2021 6:49 pm
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