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perplex

How to fix printing blobs?

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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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