"Stringing" and retraction functionality

Hi all–I found this article about ‘stringing’ to be quite interesting: https://all3dp.com/2/3d-print-stringing-easy-ways-to-prevent-it/?omhide=true&utm_source=Newsletter&utm_campaign=9e797a6119-Newsletter&utm_medium=email&utm_term=0_9dffeeddae-9e797a6119-401493393 . That said, I don’t find that I’m having any particularly great issues with ‘stringing’ (PLA only, so far for me), and I guess I wonder if the Snapmaker and/or Snapmakerjs already has ‘anti-stringing technology’ built into it? I.e., the filament ‘retraction’ functionality, say? They talk in the article about ‘direct drive extruders’ and "Bowden extruders’; do we have ‘direct drive’, I expect? Finally, the little “print temperature tower test” part is quite interesting, I may have to look into that. Though I have to say at the end of the day, I’m pretty impressed with all the PLA parts I’ve made so far with the machine, as-is (I’ve lowered my Initial Layer Print Speed to 10 mm/s and use a brim most all the time, are my only ‘permanent’ changes I’ve arrived at so far, using SMjs, only, so far). I recently printed a cylindrical part that had 48 tpi machine threads on one end, and the thing printed the threads really decently–I was impressed!

I usually print with High Quality settings. I’ve had some stringing when printing a lot of supports, but never on the actual part. My son was doing some prototype work, and he was trying to make it print faster than Fast Print. He ended up getting some stringing, but it went away when he slowed down.

Both Snapmaker3D and SnapmakerJS do have an option to “Enable Retraction”. It appears to be enabled on the 3 default print qualities. The tooltips says “Retract the filament when the nozzle is moving over a non-printed area.”

I’ve heard that “wet” or old filament can cause stringing issues. PLA will absorb humidity from the air. If it absorbs enough, the water can flash to steam in the nozzle, causing unplanned extrusions. Retraction should help with that. I live in a dry climate, so I haven’t worried about it too much. I have noticed that the PLA is getting brittle, which is a sign that it has absorbed moisture.

Yes, I do too, re: “High Quality”. I’ve also got a mill and lathe etc., and the relative magic of printing is so effortless (maybe not ‘fast’, but, ‘effortless’), that I’m pretty much never bothered by how long it takes for something to print. Ah yes, I do see ‘retraction’ in SMjs, got it, thanks. Yep, I also see stringing on supports but not on the actual part, generally. I also live in the dry world (Colorado, 5300 ft) and I don’t think PLA humidity is much of an issue for me, either.

I’ve only had stringing with PET-G. increasing the Z-Hop (i.e. retraction) improved it somewhat. I should probably reduce the speed too, which I’ll try on the next print.

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I am having considerable stringing problem. Followed some of the suggestions, and nothing.

I tried to look at the gcode, could not understand where the retraction part is.

2020-04-20-105052

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I think you want some help?- Try to print a temp.-tower first to get the right temperature of your filament.- look in the forum or www.
There are several guides on the www to help you understand what retraction does and how it could get better.

If you are looking for help here, tell us what filament at which temp. and speed you print. (PLA, Extrudr, aktik white, print with 210°C nozzel and 60°C bed)
Additionally you should write here which slicer and retraction settings do you use.

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I’ve also been having a lot of problems with stringing on my A250. I’m using Hatchbox PLA that was fresh out of the package. I’m assuming water isn’t a problem since I’m in Minnesota in winter and don’t have a humidifier on our furnace. I decide to experiment with a fast tower test with various settings to try to solve the problem. I have tried temperatures from 180C to 200C. 195C seems to have caused the least amount of stringing, but it’s still quite bad. I also have tried using retraction, but that didn’t seem to help. Does anyone have experience with this specific brand of PLA and what settings are best. I’m using Luban 4.4.0 with the ‘Precise and Strong’ setting as the base. My results have been similar to dsker’s results.

Thanks,
Eric