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alnavasa

Bad prints

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Hi guys, I am new into this world, and I don't really know what I am doing wrong.

This is the last printout I have done, Starting from the brim that its not straight lined, and bubbling, and also problems of stringing because of retraction?

If you could suggest tips in order to get better results.

Thanks

Wrong printWrong printWrong printDSC Brim?Wrong printWrong printWrong print1 print with settings2 not that bad settings ?Two fansDSC 2000DSC 1999DSC 1998DSC 1997DSC 1996DSC 1995DSC 1994fan two fans

 

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Strings: Lack off Cooling/ you need a bigger retraction/ dirty nozzle

"Bubbling": Bad bed leveling/ uneven bedplate.... the big "bubbles" on the right are from sudden pressure release from the nozzle which has built up because it could not place it before...

 

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the big "bubbles" on the right are from sudden pressure release from the nozzle which has built up because it could not place it before...

 

Maybe. It looks just like it but it could also be slicer or something else. But if you are right then it simply means you were a tiny bit too close from nozzle to bed when you levelled.

The levelling looks quite close. What is your bottom layer height? I like to make this .3mm to compensate for my levelling errors.

 

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Stringing is tricky and I should warn you that some types of PLA will string no matter what you do. But in general you need the right retraction settings and you need to lower the temp.

There are 6 retraction related settings:

1) Make sure retraction is checked on basic/quality

2) In expert settings set minimum travel to 0mm or at least something small like 1mm.

3) In expert settings set "minimal extrusion..." to 0 or something well under .1mm. There is a 160X factor on this for .1mm layers so if you extrude .02mm filament you will get 3.2mm of straight line extruding. So the default is to not retract if you print for less than 3.2mm of linear printing (for .1mm layers).

4) In expert settings you can set "combing" on or off - it shouldn't make a huge difference for this part. Lately turning this "off" seems better in the current version of Cura but in the next version it might be best to turn it back on.

5,6) For the UM Original, you can also control the amount and speed of retraction. I recommend 40mm/sec (which works well for old and new Marlin firmware) and if you printed this part then 4.5mm retraction should be about perfect:

http://www.thingiverse.com/thing:46157

 

Without the above part you need approximately 5.5mm retraction.

STRINGING/TEMPERATURE

There is also less stringing if you print slower because the pressures are lower in the nozzle. For example 35mm/sec with .1mm layers. Be patient if you care so much about stringing.

And finally temperature - colder is better but you also have to print slower if you go colder to get that viscous stuff through the nozzle. Think toothpaste consistency when PLA is cooler and honey consistency when PLA is hotter:

http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/

 

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Some of the circled areas in your photos are vertical lines that really look like they are in the STL and also the gcode. You can prove this by loading the gcode into repetier host and seeing if you still see all the artifacts. The blobbing you see in some of the pictures can probably be reduced by printing a little slower - see pumpkin picture here (post #12):

http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/?p=24010

But I've seen Cura create some bizzarre blobs for questionable, strange STL files and they stick out big time in repetier host. Repetier host is free. Once installed simply drag and drop your gcode file into it:

repetier host - free download:

http://www.repetier.com/download/

 

 

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As gr5 already mentioned. Check if it really retracts where the strings are. Just open layerview in Cura and check if there is a blue line that goes up! (those mean retraction). If cura does not retract there you have to change minimum travel in the expert settings. set it down till the upward line appears. I would not recommend to set this to 0, because it will then retract everytime it starts a new line, even in the infill. as shown https://lh4.googleusercontent.com/R4bWf9jQhmMmcfBmGVuc4-eM7Nu27DDfeaf4llTXtw4=w1007-h865-no

 

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Strings: Lack off Cooling/ you need a bigger retraction/ dirty nozzle

"Bubbling": Bad bed leveling/ uneven bedplate.... the big "bubbles" on the right are from sudden pressure release from the nozzle which has built up because it could not place it before...

 

It may be the bad leveling the problems with the brim.

Why could not place it before? I thought that maybe the bowden tube moving may cause un even pressure, but I haven't read of this problem from anyone.

 

Maybe. It looks just like it but it could also be slicer or something else. But if you are right then it simply means you were a tiny bit too close from nozzle to bed when you levelled.

The levelling looks quite close. What is your bottom layer height? I like to make this .3mm to compensate for my levelling errors.

 

The bottom layer height its the same one.

 

Stringing is tricky and I should warn you that some types of PLA will string no matter what you do. But in general you need the right retraction settings and you need to lower the temp.

There are 6 retraction related settings:

1) Make sure retraction is checked on basic/quality

2) In expert settings set minimum travel to 0mm or at least something small like 1mm.

3) In expert settings set "minimal extrusion..." to 0 or something well under .1mm. There is a 160X factor on this for .1mm layers so if you extrude .02mm filament you will get 3.2mm of straight line extruding. So the default is to not retract if you print for less than 3.2mm of linear printing (for .1mm layers).

4) In expert settings you can set "combing" on or off - it shouldn't make a huge difference for this part. Lately turning this "off" seems better in the current version of Cura but in the next version it might be best to turn it back on.

5,6) For the UM Original, you can also control the amount and speed of retraction. I recommend 40mm/sec (which works well for old and new Marlin firmware) and if you printed this part then 4.5mm retraction should be about perfect:

http://www.thingiverse.com/thing:46157

 

Without the above part you need approximately 5.5mm retraction.

STRINGING/TEMPERATURE

There is also less stringing if you print slower because the pressures are lower in the nozzle. For example 35mm/sec with .1mm layers. Be patient if you care so much about stringing.

And finally temperature - colder is better but you also have to print slower if you go colder to get that viscous stuff through the nozzle. Think toothpaste consistency when PLA is cooler and honey consistency when PLA is hotter:

http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/

 

I think it is the yellow Ultimaker PLA, its driving me crazy!.

1) Enabled

2) Right now it is in 1.5mm (I'll change it to 0.2mm)

3) Set to 0.02mm

4) Right now it is set to ON, I'll change it to NO

5,6) Thats what I have, (and I have the clip in place ;) )

Speed I used was 80 mm/s

and this pla i printed it at 210C

Should I try 200ºC ¿?

 

Some of the circled areas in your photos are vertical lines that really look like they are in the STL and also the gcode. You can prove this by loading the gcode into repetier host and seeing if you still see all the artifacts. The blobbing you see in some of the pictures can probably be reduced by printing a little slower - see pumpkin picture here (post #12):

http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/?p=24010

But I've seen Cura create some bizzarre blobs for questionable, strange STL files and they stick out big time in repetier host. Repetier host is free. Once installed simply drag and drop your gcode file into it:

repetier host - free download:

http://www.repetier.com/download/

 

 

I see that speed affects a lot, I don't know where the gcode its right now, I deleted the file, but I'll try with the next one.

I'll check that program

 

As gr5 already mentioned. Check if it really retracts where the strings are. Just open layerview in Cura and check if there is a blue line that goes up! (those mean retraction). If cura does not retract there you have to change minimum travel in the expert settings. set it down till the upward line appears. I would not recommend to set this to 0, because it will then retract everytime it starts a new line, even in the infill. as shown here

 

Nice thing! I'll check it.

So I've checked the hole settings of that print and one I've made after:

here it is:

http://ultimaker.ipbhost.com/uploads/gallery/album_702/gallery_34510_702_3052512.jpg

 

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That last post was difficult to look at - it was wider than my monitor. But I did look closely.

80mm/sec is a reasonable print speed - for low quality. 35mm/sec is better for higher quality.

That last photo shows only 2 strings per part. And the strings *only* seem to be on the top layer. I think you must be printing these parts in "one at a time" mode. Which is fine. But a bit buggy in Cura - it doesn't handle the transition from one part to the next very well. I think it's probably not a problem - you just have to cut off two strings per part with a razor blade.

 

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That last post was difficult to look at - it was wider than my monitor. But I did look closely.

80mm/sec is a reasonable print speed - for low quality. 35mm/sec is better for higher quality.

That last photo shows only 2 strings per part. And the strings *only* seem to be on the top layer. I think you must be printing these parts in "one at a time" mode. Which is fine. But a bit buggy in Cura - it doesn't handle the transition from one part to the next very well. I think it's probably not a problem - you just have to cut off two strings per part with a razor blade.

 

Yes, I considered that last one as a good print,

But definitely there is a problem with the retraction in that yellow PLA, I'll try to play with that, maybe printing in lower temp helps too

One of the problems I had in the previos print its that a screw that I printed didn't fit into the nut it was supposed to,

And one day I noticed that a cube that I printed one of the sides was 9.8 mm and the other 10mm

As you may have seen in the settings I am printing in 98% of flow, Because at the beginning the corners where made sharp, round, I did that by eye, but I want it to be better done I would like to calibrate it, the E steps, Is there a video for that? How should it exactly be done?

 

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That last post was difficult to look at - it was wider than my monitor. But I did look closely.

 

I don't know what happened with those pictures, report it to a moderator of the forum, because I have no idea what happened, they go far far away to the right of the screen.

 

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lol. That's me. A moderator. I looked at it a little closer and didn't notice anything unusual.

Anyway - be aware that if there are only 1 or 2 strings per part, and if you are printing multiple parts then this is a completely different issue. It's code that not many people use so it doesn't get quite as much attention - it's the between-print retraction stuff. Someone should fix this with a plugin or something.

 

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I strongly recommend you don't mess with steps/mm. This thing is calibrated to be spot on and if you mess with that then the software endstops will be messed up. For example if you think it is printing 3% small due to PLA shrinkage and you increase steps/mm by 3% then if you ever print something 225 or 235mm wide it will hit the clips or the wall and your part will get messed up.

There are many factors that change the size of the part to not be what you expected. PLA shrinkage is one of the smallest effects. There are many others.

For example if the bed is too hot the lower 3mm or so will kind of shrink in. due to a stretching affect that has nothing to do with cooling/density and more to do with elasticity (think rubber band) of a strand of hot pla.

This same problem exists for holes in parts - they tend to be too small due to 3 factors. The 3% shrinking of PLA, the stretchy effect (the strongest effect) and the fact that CAD converts a circle into a series of lines (like a hexagon) but all cad programs *inscribe* the polygon so that it is smaller than a circle (never larger). This is fixed by doing say 40 sides instead of say 10 sides but the bigger issue is the stretchy effect anyway.

No, the best solution, and what most people do, is you print parts twice. The first time you print it as planned. Then you measure all the critical tolerances and adjust by the error back in cad so if a cube is .1mm too narrow on the length then make it .1mm longer. If a hole diameter is .7mm too small then enlarge the whole by .7mm.

After a while though you get really good at guessing the errors on the first try.

This is nothing compared to CAD for "real" plastic parts made with injection molds where you have to also muck around with angles (after they pop out of the mold all angles change!).

 

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Oh - and if you change color or manufacturer of PLA or change your printing temp or speed or fan, then all these adjustments change a tiny bit. Again. Or if you change to ABS.

 

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http://ultimaker.ipbhost.com/uploads/gallery/album_702/gallery_34510_702_3052512.jpg

(u can edit your post -> then write a text -> mark the text -> click the link icon -> copy the link above)

have you tried to enable the cooling fan? I would enable the cooling fan and dont set the fan speed to 250 at layer 0. I would youse the settings in the expert settings. Something like fan full at 1mm. This way your fan increase by 10% every layer. this helps the nozzle to heat up and hold the temp while fan is turning on.

I would also try every Temp between 185 and 230 with 10° steps to see if the quality improves.

right now im printing a multiple parts keychain. I printed out all the parts for one keychain. After 5-6 attempts i was happy with the results. today i printed multiple parts of the keychain (likem 10 times the base of the keychain), and everything looks different, suddenly combing on is better then combing off. 230° works bettet then 200. So its always different!

just hang on!

 

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Okey Guys, so, Today I've done a print of iRobert fan ducts (Which I didn't read and they don't fit my fans) (and also a gopro frame) at 50 mms speed, 200ºC, 5 mm of retraction and 35mm/s speed

 

have you tried to enable the cooling fan? I would enable the cooling fan and dont set the fan speed to 250 at layer 0. I would youse the settings in the expert settings. Something like fan full at 1mm. This way your fan increase by 10% every layer. this helps the nozzle to heat up and hold the temp while fan is turning on.

 

I had it on at the seventh layer (on the plugin settings) but I'll change it there its better and not that messy!

So here are today prints (just one or two strings, and some points on the outer shell)

Also Underneath the overhangs It looks worse

DSC 1994

DSC 1996

DSC 1997

DSC 1995

DSC 1998

DSC 1999

DSC 2000

 

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I am finally starting to get great Prints, by slowing down the speed of the shells and increasing the infill speed.

1.2 mm of shell

I still have some problems with the over hangs bending upside, and then the nozzle pushes them down, then they bend up again and like this all the time,

I think its a problem of cooling

 

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I still have some problems with the over hangs bending upside, and then the nozzle pushes them down, then they bend up again and like this all the time,

I think its a problem of cooling

 

I also still try to get rid of this. I also thinking this is related to cooling/shrinking. Normally turning print temp down helps a bit on this one.

 

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I also still try to get rid of this. I also thinking this is related to cooling/shrinking. Normally turning print temp down helps a bit on this one.

 

Hmm, I'll try that, Right now I am printing a Ultibot with a new fan, I'll post the pictures if there are differences,

 

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I would appreciate if you don't call those overhang strings "strings" as usually "strings" are problems with retraction and oozing on non-printing moves. You can calls those noodles or something to clarify.

As far as the "overhangs bending upside", this is a serious problem. The best fix is to keep things as cold as possible and crank that fan! There are several solutions and lots of work has been done on this. Here is some discussion, some slow motion video, and fixes and much more:

http://umforum.ultimaker.com/index.php?/topic/4094-raised-edges/&do=findComment&comment=33079

Please read through the whole thing as the understanding and theories are wrong at first but get more accurate after a while. The solutions also get better. It's a fascinating topic for me as I get this problem all the time.

 

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I would appreciate if you don't call those overhang strings "strings" as usually "strings" are problems with retraction and oozing on non-printing moves. You can calls those noodles or something to clarify.

As far as the "overhangs bending upside", this is a serious problem. The best fix is to keep things as cold as possible and crank that fan! There are several solutions and lots of work has been done on this. Here is some discussion, some slow motion video, and fixes and much more:

http://umforum.ultimaker.com/index.php?/topic/4094-raised-edges/&do=findComment&comment=33079

Please read through the whole thing as the understanding and theories are wrong at first but get more accurate after a while. The solutions also get better. It's a fascinating topic for me as I get this problem all the time.

 

English its not my main language, thats why I don't really know how to call it,

So the problem with the overhangs its solved by less temp and more cooling?

I've just installed a second fan, I'll try that later this days.

Is there any source files for the WHOLE extruder in order to re cut it or re print it, because I have some broken wood parts there,

In the github Ilustrator file there are not all the files from the extruder just the two hanging things ( My UM its a revision3, I don't care upgrading it to Rev 4 extruder)

 

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