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Posted · Nylon printing issues

It happens when jumps to another surface, that the direction the nozzle goes in, build up some piece of “stick”, which I tried to change a lot of settings with no help. It made some great mess on the hard angle printing. It still works pretty good on regular printing. Cleaning nozzle has no help on this issue. 

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F7558DF3-E6C3-431E-9157-C14B9BDFF087.jpeg

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    Posted · Nylon printing issues
    4 hours ago, stu_le_brew said:

    This can often be improved by dropping the print temperature a few degrees, hard to say how many as it will vary by materiel and sometimes even different colors of the same materiel type

    Well I have been tried on changing degrees, but don’t understand why the printing get different on every time printing the same stuff, and, the branches are still there. 

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    Posted · Nylon printing issues

    You can also play with the retraction settings, because these strings occur when the print head is travelling and the nozzle oozes. So lowering print temp is one thing, higher retraction also, but in some cases you cannot avoid it. But such defects are often easy to remove in post processing.

     

    But keep also in mind that nylon absorbs really quickly moisture from the air. So keep your spool dry and if possible also during printing if it is a longer print job. If you just leave the spool on the printer for some hours it could be enough to get bad results. So maybe that's also the case, but you can dry your spool in the oven or overnight on the heated print bed covered with a towel.

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    Posted · Nylon printing issues
    7 hours ago, Smithy said:

    You can also play with the retraction settings, because these strings occur when the print head is travelling and the nozzle oozes. So lowering print temp is one thing, higher retraction also, but in some cases you cannot avoid it. But such defects are often easy to remove in post processing.

     

    But keep also in mind that nylon absorbs really quickly moisture from the air. So keep your spool dry and if possible also during printing if it is a longer print job. If you just leave the spool on the printer for some hours it could be enough to get bad results. So maybe that's also the case, but you can dry your spool in the oven or overnight on the heated print bed covered with a towel.

    Thanks for help, but I did tried on it, looks that the default settings are in the best issue. I found and changed the compensation part and it made it even more strange with no help. Maybe a “pre retract” will help but I did not find any settings on this. And of course I tried to keep my filament dry, at least I did not get any bubble sound during printing.. 

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    Posted · Nylon printing issues

    I had some similar issues with PETG and I tried a lot. Turning off combing helped also, so maybe you can also give it a try,

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    Posted · Nylon printing issues
    2 minutes ago, Smithy said:

    I had some similar issues with PETG and I tried a lot. Turning off combing helped also, so maybe you can also give it a try,

    Thanks for help! I’ll try it, and can you tell me where or the exact words is the section please? I am using Chinese system, not familiar with those words.. 

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    Posted · Nylon printing issues

    When you switch Cura to English then just enter "combing" in the search field and you should get it. I am currently not in front of my Cura so I cannot check the section.

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    Posted · Nylon printing issues
    Just now, Smithy said:

    When you switch Cura to English then just enter "combing" in the search field and you should get it. I am currently not in front of my Cura so I cannot check the section.

    That might help, but I’m not at my printer either. 😄 I’ll try it tonight!

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    Posted · Nylon printing issues

    The search field above the settings is a great feature, you need only a part of the name of a setting to get it and you get it in any way regardless of your visibility settings,

     

    good luck 😀

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    Posted · Nylon printing issues
    2 hours ago, Smithy said:

    The search field above the settings is a great feature, you need only a part of the name of a setting to get it and you get it in any way regardless of your visibility settings,

     

    good luck 😀

    Kind of sure I tried it, and it is making the printing worse now, the drag is crazy with this off.. 

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    Posted · Nylon printing issues

    As said, I had good success with PETG, could be different with Nylon, but that was the only idea I had left 🙂 

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    Posted · Nylon printing issues
    4 hours ago, Smithy said:

    As said, I had good success with PETG, could be different with Nylon, but that was the only idea I had left 🙂 

    Never mind, it is what it is, I just have to cut those point, where the nozzle jumps to another single surface. Except those spots, it seems has no big issues in printing!

    Thus I still want deal with it... 

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    Posted · Nylon printing issues

    Printing slow, cool and in thin layers reduces the effect for PET (I have no experience with nylon), but does not eliminate it. One cause is the internal pressure of molten material in the nozzle, which then leaks a little bit while traveling. So, less speed = less pressure = less leaking. That droplet is deposited on the next wall the nozzle encounters after traveling through air. On the next pass, the droplet is deposited on the previous droplet, and so on, causing these nice "insect antennas". Watch closely and you see them growing. Another cause can be material accumulating on the outside of the nozzle, sagging, and then being deposited onto the print, but that gives bigger brown blobs usually. Sticky, rubbery materials like PET have this way more than yoghurt-like materials as PLA. And obviously, wet material that starts cooking off water in the nozzle, thus generating steam and increasing internal pressure and forcing material out, is not going to help. So keep nylon and ABS *very* dry, and even keep them in a drybox while printing. Nylon absorbs way too much moisture in only a few hours. There are threads on the forum of people who modified or built dryboxes to use them while printing.

     

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    Posted (edited) · Nylon printing issues
    17 minutes ago, geert_2 said:

    Printing slow, cool and in thin layers reduces the effect for PET (I have no experience with nylon), but does not eliminate it. One cause is the internal pressure of molten material in the nozzle, which then leaks a little bit while traveling. So, less speed = less pressure = less leaking. That droplet is deposited on the next wall the nozzle encounters after traveling through air. On the next pass, the droplet is deposited on the previous droplet, and so on, causing these nice "insect antennas". Watch closely and you see them growing. Another cause can be material accumulating on the outside of the nozzle, sagging, and then being deposited onto the print, but that gives bigger brown blobs usually. Sticky, rubbery materials like PET have this way more than yoghurt-like materials as PLA. And obviously, wet material that starts cooking off water in the nozzle, thus generating steam and increasing internal pressure and forcing material out, is not going to help. So keep nylon and ABS *very* dry, and even keep them in a drybox while printing. Nylon absorbs way too much moisture in only a few hours. There are threads on the forum of people who modified or built dryboxes to use them while printing.

     

    Your description makes a lot of sense! I had planing on making a dry box, I’m not quite sure how the humidity is now, I just feel like it is “crispy”, not soft. Did not learned if the bobble sound is the only effect when the material is wet. And still think “pre-retraction” might help on these kind of issue, it will help to limit the internal pressure in the nozzles. The plan I get from your teaching is to turn off the fan, using a lower temperature and low speed at the same time. I’ll try it tonight. And actually I feel it might not work, looks like it is the pressure remained in the end of nozzle, like a spring bouncing in and out, and made that wired sticks. 

    Edited by minercraftal
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    Posted · Nylon printing issues
    7 hours ago, geert_2 said:

    Printing slow, cool and in thin layers reduces the effect for PET (I have no experience with nylon), but does not eliminate it. One cause is the internal pressure of molten material in the nozzle, which then leaks a little bit while traveling. So, less speed = less pressure = less leaking. That droplet is deposited on the next wall the nozzle encounters after traveling through air. On the next pass, the droplet is deposited on the previous droplet, and so on, causing these nice "insect antennas". Watch closely and you see them growing. Another cause can be material accumulating on the outside of the nozzle, sagging, and then being deposited onto the print, but that gives bigger brown blobs usually. Sticky, rubbery materials like PET have this way more than yoghurt-like materials as PLA. And obviously, wet material that starts cooking off water in the nozzle, thus generating steam and increasing internal pressure and forcing material out, is not going to help. So keep nylon and ABS *very* dry, and even keep them in a drybox while printing. Nylon absorbs way too much moisture in only a few hours. There are threads on the forum of people who modified or built dryboxes to use them while printing.

     

    Tried 220 C° and a lower speed, and the branch is just moved away instead of being limited. This time I heard the bobble sound, which tells me that there is some moisture issue appears. Anyway, your suggestion do helped me learned something about my printer, and otherwise I still believe my inventory of pre-retraction might helps. But I don’t know programming, cannot help myself adding some change to Cura... 

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    Posted (edited) · Nylon printing issues

    Hi minercraftal,

     

    I'll agree with others saying your filament is contaminated with water. What we see here is that water affected filament entering the hot end, create vapor that's increase the pressure inside the hot end and then lead to over extruding that's erratic. Nylon is one of the most sensitive (close to PVA), for attracting water in high humidity environment. 

    So, be there when nylon filament printing is done and store your valuable filament into sealed container with silica bag to keep it ready for next print.

    Also, a lo temp for nylon might be more like (235-240) deg. C. Normally nylon tend to string a little, so a little tuning here is often needed.

    Printing with nylon need some attention for cold draft into the lo end of the printer. Such draft can reduce the bounding between the layers of your model, very important. So cover up the lo part an the front. Also using a top hat that's have an exhaust valve to vent out fumes, however when printing with nylon the exhaust vent is closed and heat is vented on the open underside of the top hat.-

    Typical bed temp is about 75 deg. C. This temperature create a draft from lo through the upper part of the printer.

     

    In Cura there is a tools to protect your object from draft, -use it, it work very well for me.

    It's named "Draft Shield" and it's used to shield models, keep the heat and prevent models to warp.

    This one have been sometime in Cura, but still located under experimental (Cura 4.7.1).

     

    Here is it:

    Draft_Shield.thumb.jpg.fcee60f213a15aab9866d952bf1036ec.jpg

     

     

    When printing Nylon, the cooling fan for your model is off -all the time..

    Edit: Using no cooling fan is mainly true for smaller objects, -some fan use is done when printing bigger object so here it is very important to follow the producers advice and your printers capabilities in this matter. (Heat insulation, doors etc.)

     

    By the way, I'm mostly printing around (250-255) deg. C for the brand I'm using.

    So last, select a good 1 class filament for your nylon printing -that's the important thing to do here..

     

    Good luck with your nylon printing.

     

    Thanks

    Torgeir

     

    Edited by Torgeir
    Additional info.
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    Posted · Nylon printing issues
    6 hours ago, Torgeir said:

    Hi minercraftal,

     

    I'll agree with others saying your filament is contaminated with water. What we see here is that water affected filament entering the hot end, create vapor that's increase the pressure inside the hot end and then lead to over extruding that's erratic. Nylon is one of the most sensitive (close to PVA), for attracting water in high humidity environment. 

    So, be there when nylon filament printing is done and store your valuable filament into sealed container with silica bag to keep it ready for next print.

    Also, a lo temp for nylon might be more like (235-240) deg. C. Normally nylon tend to string a little, so a little tuning here is often needed.

    Printing with nylon need some attention for cold draft into the lo end of the printer. Such draft can reduce the bounding between the layers of your model, very important. So cover up the lo part an the front. Also using a top hat that's have an exhaust valve to vent out fumes, however when printing with nylon the exhaust vent is closed and heat is vented on the open underside of the top hat.-

    Typical bed temp is about 75 deg. C. This temperature create a draft from lo through the upper part of the printer.

     

    In Cura there is a tools to protect your object from draft, -use it, it work very well for me.

    It's named "Draft Shield" and it's used to shield models, keep the heat and prevent models to warp.

    This one have been sometime in Cura, but still located under experimental (Cura 4.7.1).

     

    Here is it:

    Draft_Shield.thumb.jpg.fcee60f213a15aab9866d952bf1036ec.jpg

     

     

    When printing Nylon, the cooling fan for your model is off -all the time..

    By the way, I'm mostly printing around (250-255) deg. C for the brand I'm using.

    So last, select a good 1 class filament for your nylon printing -that's the important thing to do here..

     

    Good luck with your nylon printing.

     

    Thanks

    Torgeir

     

    Thank you for your series reply. I am planing on making a dry box, so I cannot try your suggestions now, but I will take it and try it after I am done with my dry box! 

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    Posted · Nylon printing issues

    If you don't want to make your own dry box, I can also suggest the Polybox, works well for me.

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    Posted · Nylon printing issues
    7 hours ago, Smithy said:

    If you don't want to make your own dry box, I can also suggest the Polybox, works well for me.

    I like to diy, that’s why I’m playing 3d printer... tkx for suggestions 

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