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How to fix printing blobs?


perplex

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Posted · How to fix printing blobs?

ill attach a image to show you what im trying to fix

 

ive tried reading online to see what people say to fix it, but all the settings ive tried didnt work

 

things ive tried are

 

Z seam alignment from random to shortest

 

Retraction distance from 1.2 to .4

 

Travel combing mode from off to All

 

Turned off retract at layer change

 

Retraction distance from 1.2 to 2.2

 

Retract at layer change to off

 

Retract before outer wall off

none of the settings worked, is there something else i can try?

IMG_20180214_193909.jpg

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    Posted · How to fix printing blobs?

    Have you tried printing much slower and cooler? And keep the material flow as constant as possible (=print all things with equal speed)? So that there is no excess pressure build-up in the nozzle? On my UM2 I would aim for 25...30mm/s, and the lowest temp that does not give underextrusion, maybe plus 5°C. Do a test and adjust speed and temp on the fly.

     

    In my experience, some materials tend to have this more than others, especially somewhat rubbery materials like PET. The blobs often come about when the printer travels and then lands again, when the nozzle leaks due to internal pressure build-up. Or when material accumulates on the outside of the nozzle, sags, and is deposited on the print.

     

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    Posted · How to fix printing blobs?
    23 minutes ago, geert_2 said:

    Have you tried printing much slower and cooler? And keep the material flow as constant as possible (=print all things with equal speed)? So that there is no excess pressure build-up in the nozzle? On my UM2 I would aim for 25...30mm/s, and the lowest temp that does not give underextrusion, maybe plus 5°C. Do a test and adjust speed and temp on the fly.

     

    In my experience, some materials tend to have this more than others, especially somewhat rubbery materials like PET. The blobs often come about when the printer travels and then lands again, when the nozzle leaks due to internal pressure build-up. Or when material accumulates on the outside of the nozzle, sags, and is deposited on the print.

     

    ill try a slower speed and see how that goes

    1 minute ago, Job_van_gennip said:

    Can you post your settings like speed, temp etc. 

    is there a easy way to post all settings?

     

    temp was 205c PLA (this is the worst pla ive used so far as well)

    print speed was 50 (normally i do 40 but i did abit faster for the test but ill drop it back)

    outer wall speed 25

    wall count 2 + alternative extra wall ticked

     

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    Posted · How to fix printing blobs?

    Have you already tried maybe lowering the temperature? It really looks like overextrusion. It does not look like a retraction problem since it is all over the print and not just on one place in the model. Try to print in a few different temps maybe as low as 195. It could really be the fillament that you use.

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    Posted · How to fix printing blobs?
    40 minutes ago, perplex said:

    ill try a slower speed and see how that goes

    is there a easy way to post all settings?

     

    temp was 205c PLA (this is the worst pla ive used so far as well)

    print speed was 50 (normally i do 40 but i did abit faster for the test but ill drop it back)

    outer wall speed 25

    wall count 2 + alternative extra wall ticked

     

    Hi as mentioned earlier set your speeds the same - you have print speed and outer wall speed that are different. This is vital, you need to keep nozzle pressure consistent. I would drop all print speeds to 30 mm/s; your goal is to get a decent print, get that and then you can always play with speeding it up if you want to. Temp. is meaningless unless we know speed and layer height. If you are printing hot that will not help you either.

     

    Were the parts in you pic printed separately or were they all on the print bed at the same time?

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    Posted · How to fix printing blobs?
    11 hours ago, Job_van_gennip said:

    Have you already tried maybe lowering the temperature? It really looks like overextrusion. It does not look like a retraction problem since it is all over the print and not just on one place in the model. Try to print in a few different temps maybe as low as 195. It could really be the fillament that you use.

    i just lowered the temp to 195 and same issue

    10 hours ago, yellowshark said:

    Hi as mentioned earlier set your speeds the same - you have print speed and outer wall speed that are different. This is vital, you need to keep nozzle pressure consistent. I would drop all print speeds to 30 mm/s; your goal is to get a decent print, get that and then you can always play with speeding it up if you want to. Temp. is meaningless unless we know speed and layer height. If you are printing hot that will not help you either.

     

    Were the parts in you pic printed separately or were they all on the print bed at the same time?

    i changed all speeds to 30, but kept travel speeds higher

     

    no change, im getting the same issue

     

    i know printing in straight lines is mostly fine, but printing this circle is super bad

     

    im running out of ideas

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    Posted · How to fix printing blobs?

    Once I noticed that sort of thing happened when my nozzle started to crap out from just so much usage. They do have a lifespan no matter how well you take care of them and do not use abrasives.

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    Posted · How to fix printing blobs?
    17 hours ago, geert_2 said:

    Have you tried printing much slower and cooler? And keep the material flow as constant as possible (=print all things with equal speed)? So that there is no excess pressure build-up in the nozzle? On my UM2 I would aim for 25...30mm/s, and the lowest temp that does not give underextrusion, maybe plus 5°C. Do a test and adjust speed and temp on the fly.

     

    In my experience, some materials tend to have this more than others, especially somewhat rubbery materials like PET. The blobs often come about when the printer travels and then lands again, when the nozzle leaks due to internal pressure build-up. Or when material accumulates on the outside of the nozzle, sags, and is deposited on the print.

     

    so that didnt work, i tried slower speed and lower temp, same thing

    2 hours ago, kmanstudios said:

    Once I noticed that sort of thing happened when my nozzle started to crap out from just so much usage. They do have a lifespan no matter how well you take care of them and do not use abrasives.

    i havent used it much, so i dont think that is the issue

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    Posted · How to fix printing blobs?

    If the cause is not clear, maybe you could try along this line: first try to use a "known good" filament, which gave no problems in the past. Carefully watch what happens while printing, at exact which moment the blobs appear, and why. Sometimes you can see what is going on. And then, on the fly adjust all sorts of parameters a bit up and down, one by one: temp, speed, fans, material flow? Set each one back to default before changing the next.

     

    Of course, also check if the nozzles are clean (do atomic pulls), if the feeder wheel and traject are clean, if feeder pressure is correct, and if the whole feeding traject flows smoothly. And check filament diameter. I could imagine that this sort of problems could be caused by irregular feeding: pressure somewhere in the feeding traject building up, and then suddenly jerking forward. Or a piece of filament stuck in the knurls of the feeder wheel, causing an irregular diameter.

     

    If none of this helps, maybe you could design a new model with the same outer dimensions in a simple editor of your choice? I would suggest DesignSpark Mechanical: easy to learn, powerfull, and free. But do *not* use SketchUp. See if that has the same problem? This in case weird model geometry might also play a role?

     

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    Posted · How to fix printing blobs?

    What is the diameter of your part? I have a similar one, which I will print at your diameter, and post my settings.

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    Posted · How to fix printing blobs?
    15 hours ago, yellowshark said:

    What is the diameter of your part? I have a similar one, which I will print at your diameter, and post my settings.

    26 OD

    18 ID

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    Posted · How to fix printing blobs?

    5a889ca277188_Hydrailicsleeve1.thumb.jpg.73b096d061b0969b2a81ccfbe8422b5a.jpgHi, Here is my result – it looks better in real life but close up and flash never do 3D prints any favours. As you can see there are none of your problems present.

    Settings were…

    Software: Cura 2.4

    Main settings

                   Layer height: .150

                   All printing speeds:30mm/s

                   Temp. 200

    Line width 0.4

    Shell

    Walls: 0.8, i.e. 2

    Outer wall wipe distance: 0

    Outer wall inset: 0

    Outer walls before inner walls:  no

    Alternate extra wall: no

    Compensate wall overlaps: no

    Z seam alignment: random

    Infill

                   Density: 100% - on this model 100% is faster than 20%

    Infill overlap %: 15

    Skin overlap %: 5

    Infill wipe distance: 0

    Infill before walls: no

    Material

                   Flow: 100

                   Enable retraction: yes

                   Retract at layer change: no

                   Retraction distance: 5.5

                   Retraction speed: 50

    Retraction extra prime amount: 0

    Retraction minimum travel: 0.8

    Maximum retraction count: 90

    Minimum extrusion distance window: 5.5

    Travel – all settings off/no

    Fan speed

                   Regular/maximum speeds: 100

                   Initial speed: 0

                   Regular fan speed at layer: 4

    Mesh fixes – set to no/0

    Special modes

                   Surface mode: normal

    Experimental – set to no/0

    Hydrailic sleeve1.jpg

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    Posted · How to fix printing blobs?

    Sorry I seem to have dumped a copy of my pic into your initial post. I have looked for a help manual but cannot find one and have no idea how to get a pic into my post - it was so easy on the original forum.

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    Posted · How to fix printing blobs?

    I always just click and drag images into the spot after where I am typing from source folder on computer.

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    Posted · How to fix printing blobs?

    Yeah I eventually worked that out but as you can see getting it actually positioned correctly seems to require some extra dexterity*|

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    Posted · How to fix printing blobs?
    7 hours ago, yellowshark said:

    Hi, Here is my result – it looks better in real life but close up and flash never do 3D prints any favours. As you can see there are none of your problems present.

    Settings were…

     

    so i changed as many of my settings to yours and still having the issue

     

    i am running a newer version of cura but thats about it

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    Posted · How to fix printing blobs?

    Maybe not all things are equal such as printer, environment and batch/brand of material.

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    Posted · How to fix printing blobs?

    Hmn, I actually thought it was your retraction settings that were probably causing the problem - they are way out compared with anything I have ever used.

     

    Can you print any other model, even just a cube, that comes out perfectly? Or is the problem present on everything you print?

    What printer and PLA filament manufacturer are you using

    I guess you are using Cura 3.n. That will have more settings than 2.4. These will have defaults set, probably. Can I suggest you go through the settings again and if something (i.e. that I have not mentioned) is not needed then untick them or set them to 0. This needs a bit of care as I have not mentioned all my settings above - but certainly most of them - but then may just be something that is affecting it. Actually better still  use a snipping tool (Windows has one) and just copy all your settings and post here.

     

    As @kmanstudios notes, anything strange about your environment, ultra hot or cold?

    If you have them are you printing with your door open and roof off

     

    Now we will have different printers, I have a 3ntr, so you may need to run a different extruder temp than me. Perhaps you could test with 190 and 210 and see what if any difference you get.

     

    I think you mentioned that the filament was not great anyway. if so get some decent filament; Colorfabb is good or if you are in the UK then imho Faberdashery is better and you can buy it in lengths rather than reels so spend less.

     

    Also looking at your picture again the two middle reels seem to have a decent top surface but the two end ones do not. Did you kill those two prints before getting to the end?

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    Posted · How to fix printing blobs?
    3 minutes ago, yellowshark said:

    Hmn, I actually thought it was your retraction settings that were probably causing the problem - they are way out compared with anything I have ever used.

     

    Can you print any other model, even just a cube, that comes out perfectly? Or is the problem present on everything you print?

    What printer and PLA filament manufacturer are you using

    I guess you are using Cura 3.n. That will have more settings than 2.4. These will have defaults set, probably. Can I suggest you go through the settings again and if something (i.e. that I have not mentioned) is not needed then untick them or set them to 0. This needs a bit of care as I have not mentioned all my settings above - but certainly most of them - but then may just be something that is affecting it. Actually better still  use a snipping tool (Windows has one) and just copy all your settings and post here.

     

    As @kmanstudios notes, anything strange about your environment, ultra hot or cold?

    If you have them are you printing with your door open and roof off

     

    Now we will have different printers, I have a 3ntr, so you may need to run a different extruder temp than me. Perhaps you could test with 190 and 210 and see what if any difference you get.

     

    I think you mentioned that the filament was not great anyway. if so get some decent filament; Colorfabb is good or if you are in the UK then imho Faberdashery is better and you can buy it in lengths rather than reels so spend less.

     

    Also looking at your picture again the two middle reels seem to have a decent top surface but the two end ones do not. Did you kill those two prints before getting to the end?

    the top surfaces look like that coz i stop the print as i can see i still have the same issue

    i tried a different filament, and it is better but not perfect.

     

    maybe ill try resetting the cure settings to default and see what that does

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    Posted · How to fix printing blobs?

    Well you could; I have never used their standard settings and I have seen examples of them quoted on the forum with settings I consider poor. But you never know :sunglass:. If you can post your model somewhere I am happy to print it with my settings and see what happens.

     

    You did not say if this was your first model or whether you have printed other models previously which have been good?

     

    When you say you tried a different filament, which was better, was that print using my settings or did you do it before I posted them? Can you post a pic of that "better" model.

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    Posted · How to fix printing blobs?
    Just now, yellowshark said:

    Well you could; I have never used their standard settings and I have seen examples of them quoted on the forum with settings I consider poor. But you never know :sunglass:. If you can post your model somewhere I am happy to print it with my settings and see what happens.

     

    You did not say if this was your first model or whether you have printed other models previously which have been good?

     

    When you say you tried a different filament, which was better, was that print using my settings or did you do it before I posted them? Can you post a pic of that "better" model.

    sorry, this isnt my first print, square box seems fine, just the round im struggling with , also im not using the ultimaker. i did print something similar a while ago and that looks great, but i dont remember if that was before i updated cure and i had to put my setting back in.

     

     

    your settings still had the issue but made it look neater

     

    so the green is the same settings and the big gray one and the little gray one is your settings

    IMG_20180218_222712.thumb.jpg.651d3e8aafc88276c94b056aeb89ffa2.jpg

     

     

    this is a different model what i did a while ago, there is no blobs but there is a little bit of layer lifting what i also need to work out, thinking it was just to cold when printing, but it shows its some sort of setting, i just dont know what it is

    IMG_20180218_222808.thumb.jpg.a6da8bd386b6facda9c08d8e94a187bd.jpg

     

     

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    Posted · How to fix printing blobs?

    Have you tried decimating the design and reprinting? Those blobs usually result from issues with either underrun gcode caching, or fans/electrical pegging thet cause a tiny unintended delay. That would explain while placement is perfect, just results look ugly. If you exported from a pro CAD package and the resolution is over 1million polygons even though the part is simple, that would be something to encourage my theory. ;)

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    Posted · How to fix printing blobs?
    25 minutes ago, mattgriffin said:

    Have you tried decimating the design and reprinting? Those blobs usually result from issues with either underrun gcode caching, or fans/electrical pegging thet cause a tiny unintended delay. That would explain while placement is perfect, just results look ugly. If you exported from a pro CAD package and the resolution is over 1million polygons even though the part is simple, that would be something to encourage my theory. ;)

    This is a thought to pursue as we had something happen like that in this thread. The model passes all STL checks, but the actual configuration of the vertices and edges created an issue when slicing. I used a modifier in 3DS MAX to make the geometry a little different and it sliced ok after that.

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    Posted · How to fix printing blobs?
    21 hours ago, mattgriffin said:

    Have you tried decimating the design and reprinting? Those blobs usually result from issues with either underrun gcode caching, or fans/electrical pegging thet cause a tiny unintended delay. That would explain while placement is perfect, just results look ugly. If you exported from a pro CAD package and the resolution is over 1million polygons even though the part is simple, that would be something to encourage my theory. ;)

    i use autodesk inventor, any tips for that?

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