Jump to content
Ultimaker Community of 3D Printing Experts
h2befjon

Print quality degrading and prints stopping by themselves

Recommended Posts

Hello! I am new to the 3d printing seen and I just received my Ultimaker 2 about a week ago. I did everything necessary and accordingly to calibrate the bed and I have done some research understanding how different options can affect a print. Well over the past 30+hrs I had set to print a t800 skull heres the link (http://www.thingiverse.com/thing:548335) the job started to look good however as the layers got higher the fill and quality of the print degraded, I noticed this with smaller objects I printed also. I dont understand why it is doing this can anybody help me?

I used pla filament that came with the unit

settings were

.2mm layer height

.4mm shell thickness

60 heated bed

210 headed nozzle

Also has anybody experienced their prints "finishing" without the print actually being finished? When I came home from work I was expecting a finished piece not a finished partial piece....

here are some pictures:

20311603938_1ff46e15e3_c.jpg

20505968531_61f16e7e8c_c.jpg

20505969461_0308d0e8a6_c.jpg

20473424866_f6a47e6369_b.jpg

19878732923_4ebb75f7eb_b.jpg

20505971291_b1dcb5a942_b.jpg

Share this post


Link to post
Share on other sites

You have severe underextrusion - possibly ending with a nozzle clog due to the filament sitting inside the nozzle at high temp for hours but more likely ground up at the feeder and so no longer extruding.

It can be caused by many things. What is your print speed? Heck here is my standard anser to causes of underextrusion - start with #1 and print slower (half speed) *and* 10C hotter. Another item I don't think is on the list below is if you have too many retractions it can suddenly stop printing due to filament ground flat. But you typically need a hundred retractions on the same layer.

============

As far as underextrusion causes - there's just so damn many. none of the issues seem to cause more than 20% of problems so you need to know the top 5 issues to cover 75% of the possibilities and 1/4 people still won't have the right issue. Some of the top issues:

1) Print slower and hotter! Here are top recommended speeds for .2mm layers (twice as fast for .1mm layers):

20mm/sec at 200C

30mm/sec at 210C

40mm/sec at 225C

50mm/sec at 240C

The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA.

2) Isolator - this is most common if you've printed extra hot (>240C) for a few hours or regular temps (220C) for 100 hours. It warps. It's the white part touching the heater block. Test it by removing it and passing filament though it by hand.

3) Curved filament at end of spool - if you are past half way on spool, try a fresh spool as a test.

4) curved angle feeding into feeder - put the filament on the floor -makes a MASSIVE difference.

5) Head too tight? Bizarrely MANY people loosen the 4 screws on the head by just a bit maybe 1/2 mm and suddenly they can print just fine! Has to do with pressure on the white teflon isolator.

5b) Bowden pushing too hard - for the same reason you don't want the bowden pushing too hard on the isolator.

5c) Spring pushing too hard. Although you want a gap you want as small as possible a gap between teflon isolator and steel isolator nut such that the spring is compressed as little as possible.

6) clogged nozzle - the number one problem of course - even if it seems clear. There can be build up on the inside of the nozzle that only burning with a flame can turn to ash and remove. Sometimes a grain of sand gets in there but that's more obvious (it just won't print). Atomic method (cold pull) helps but occasionally you need to remove the entire heater block/nozzle assembly and use flame.

7) feeder spring issues - too tight, too loose

8) Other feeder issues, one of the nuts holding machine together often interferes with the feeder motor tilting it enough so that it still works but not very well. Other things that tilt the feeder motor, sleeve misaligned so it doesn't get a good grip. Gunk clogging the mechanism in there.

9) Filament diameter too big - 3mm is too much. 3mm filament is usually 2.85mm nominal or sometimes 2.9mm +/- .05. But some manufacturers (especially in china) make true 3.0mm filament with a tolerance of .1mm which is useless in an Ultimaker. It will print for a few meters and then clog so tight in the bowden you will have to remove the bowden from both ends to get the filament out. Throw that filament in the trash! It will save you weeks of pain

9b) Something wedged in with the filament. I was setting up 5 printers at once and ran filament change on all of them. One was slowly moving the filament through the tube and was almost to the head when I pushed the button and it sped up and ground the filament badly. I didn't think it was a problem and went ahead and printed something but there was a ground up spot followed by a flap of filament that got jammed in the bowden tube.

10) Hot weather. If air is above 30C or even possibly 25C, the air temperature combined with the extruder temperature can soften the filament inside the feeder such that it is getting squeezed flat as it passes through the feeder - this is obvious as you can see the problem in the bowden. The fix is to add a desk fan blowing on the back of the printer.

  • Like 1

Share this post


Link to post
Share on other sites

Since the underextrusion is so even; in addition to all above points could be failing temp sensor. They have been known to "read" 210 when they are actually just 195 ..

If you cannot do everything @gr5 suggests, my recommendation is:

1. cold pulls Atomic clean (Epic instructions at 3dverkstan.se)

2. speed 30-40mm/s

3. increase temp to 225

Oh yes, and if you have printed at higher temp like 250 etc (ABS, etc)

then there will be carbon buildup in nozzle and you definately need to perform cold pulls until the "end" comes out clean.

See if that fixes it.

Edited by Guest
  • Like 1

Share this post


Link to post
Share on other sites

Yes - there are many other things that can cause underextrusion so test the above things and let us know what you find. Here's how to test temp sensor:

====

Temp Sensor bad - even the good ones vary by +/- 5C and bad ones can be any amount off - they usually read high and a working sensor can fail high slowly over time. Meaning the sensor thinks you are at 220C but actually you are at 170C. At 170C the plastic is so viscous it can barely get out of the nozzle. You can verify your temp sensor using this simple video at youtube - on you tube search for this: mrZbX-SfftU

  • Like 2

Share this post


Link to post
Share on other sites

Also temp sensors that fail drastically (more than 30C) can be working fine at 20C but still - make sure it reads 20C when at room temperature. But typically they work fine at 20C and only when you heat them up do the parts start to seperate and the resistance increases fooling the UM circuitry into thinking the temp is higher.

  • Like 2

Share this post


Link to post
Share on other sites

I may be missing your point... but what is the issue? you mean the lines on the top surface?

seems there's only a tiny slope in the top, so it makes you see the layer transitions in the top surface.. to improve you can go to a lower layer height, but you probably don't want that on the complete print, it will take ages...

You could use a lower layer height only on the top layers, but probably not yet on the new cura (not sure) in old cura you can use plugins to do this..

Share this post


Link to post
Share on other sites

You need to print the inside after the outside. On the last stable nonbeta oldcura version they added that option. On the new cura I suppose there's a way to do it?

When the slicer prints the inside before the outside the inner lines (if the thickness it's low) show outside. Try making the outside shell bigger to get a cleaner outside (that if you can't change the lrint order on your slicer). Try 1.2 shell thickness or 1.6 to be sure.

Share this post


Link to post
Share on other sites

Those vertical lines are stepper motor related if i think its the lines you mean, if you print in 35mm/s they should be less, the quicker you print you'll notice weird patterns also. i print at 35 50 and 70 and the moire pattern as i call it is worst on 70 and cleanest at 35, so try a bit slower? If not then i don't know. at least you don't have a jam anymore, i'm jealous, lol.

Share this post


Link to post
Share on other sites

Interesting, as i print with 0 infill and I still get those lines. On flat faces. It all depends on the angle of the face.

I don't always get it, I think it may be bad modelling or poly normal related issues. As in faces faceing the wrong way (which really should be fine) or bad smoothing introducing subtle curves on flat faces that shouldn't have them.

I'll post some pics when i get back.

...then again i'm using an old cura where the infill 'would be' straight not diagonal like in the pics above don't know what the new one is like.

Edited by Guest

Share this post


Link to post
Share on other sites

here are what my 'flat' sides look like. no infill but with support, and quite thick walls.

doesnt bother me too much but it would be nice to be able to remove them. printed at 70mm/s um blue PLA 220dg.

I have my trusty acetone if i want them gone, lol.

20150904_203359.thumb.jpg.3fb55c4f4c37ae529d10928bfa5271de.jpg

20150904_203359.thumb.jpg.3fb55c4f4c37ae529d10928bfa5271de.jpg

Edited by Guest

Share this post


Link to post
Share on other sites

I just want to say thank you all for trying to help me out I really appreciate it. Now, I don't why the Honda valve cover is not printing smoothly I tried messing with the angles and setting in cura and it did nothing, I give up. I have yet to reprint the terminator jaw because I'm printing these Honda valve covers however, I'm running into the same issue I had on the first post, under extrusion. When I go on cura to duplicate the valve cover and then set it to print everything seems to print normal however once it starts on adding on layers there's little pla coming out. I was able to mess with the speed on the machine and set it to a slower pace and that seemed to work but I ended up canceling the print and just printing singles.

Has anyone else had this issue when printing duplicate or multiple prints?

Share this post


Link to post
Share on other sites

Has anyone else had this issue when printing duplicate or multiple prints?

 

You keep describing underextrusion which although it has about 40 possible causes (10 listed above) none of the causes I know about have anything to do with printing multiple prints. Did you check any of the 10 things above out? Like printing slower? The bottom layer prints slower so that might be why it comes out without as much underextrusion. Please re-read the very first answer to your original post. Above - up at the top. The one with the listing of causes for underextrusion which are numbered. As far as I can tell you didn't test out a single one of those 10 possible causes - when you do start experimenting there are more causes but don't give up before you start! Usually I can diagnose the cause pretty quickly.

Share this post


Link to post
Share on other sites

Personally i just think hes got a blocked nozzle. Dude, just do some atomic pulls before each print and you should be fine. And print slower if you want the surface to be better quality.

I tried the filament on the floor thing btw........never again. In a million years. Unless you are sitting with it throughout. Unless you want to spend hours cleaning out your burn nozzle that is. Iroberts feeder and a pipecleaner to clear the dust of the filament going in sounds much better. If your gonna print off the roll do it like this.

20150425_140758.thumb.jpg.2f7d7517bd0c9ce09ce1a7f4ec49e101.jpg

20150425_140758.thumb.jpg.2f7d7517bd0c9ce09ce1a7f4ec49e101.jpg

Share this post


Link to post
Share on other sites

Personally i just think hes got a blocked nozzle. Dude, just do some atomic pulls before each print and you should be fine. And print slower if you want the surface to be better quality.

I tried the filament on the floor thing btw........never again. In a million years. Unless you are sitting with it throughout. Unless you want to spend hours cleaning out your burn nozzle that is. Iroberts feeder and a pipecleaner to clear the dust of the filament going in sounds much better. If your gonna print off the roll do it like this.

20150425_140758.thumb.jpg.2f7d7517bd0c9ce09ce1a7f4ec49e101.jpg

 

It's not the nozzle I already tried the atomic method everything is clean, I used move material and the pla oozes out beautifully and even switched the ptfe coupler.

Share this post


Link to post
Share on other sites

 

Has anyone else had this issue when printing duplicate or multiple prints?

 

You keep describing underextrusion which although it has about 40 possible causes (10 listed above) none of the causes I know about have anything to do with printing multiple prints.  Did you check any of the 10 things above out?  Like printing slower?  The bottom layer prints slower so that might be why it comes out without as much underextrusion.  Please re-read the very first answer to your original post.  Above - up at the top.  The one with the listing of causes for underextrusion which are numbered.  As far as I can tell you didn't test out a single one of those 10 possible causes - when you do start experimenting there are more causes but don't give up before you start!  Usually I can diagnose the cause pretty quickly.

 

I did mess with the speed on the printer itself and a slower speed did seem to help a little with the multiple print but after awhile it started underextruding again and I stopped the print.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Announcements

  • Our picks

    • Architect Design Contest | Vehicles.
      We're open for entries! - Design and submit your 3D designs of architectural entourage - vehicles - for a chance to win a large filament pack. Presenting an idea, an architectural design or something as big as an urban project isn't easy. A scaled model can really help to get your idea across.
        • Like
      • 26 replies
    • What The DfAM?
      I'm Steve Cox, an experienced engineer familiar with 3D printing. I wanted to share some DfAM guidelines with this community to help and make stronger parts.
      I'm also an Autodesk Certified Instructor for Fusion 360, so many of the images in ...
        • Thanks
        • Like
      • 23 replies
×

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!